XSL Formatting Objects

XSL Formatting Objects

XSL-FO

Why XSL-FO? Some History• The history of HTML shows that, in the

early days, both its designers and its users were confused about its purpose

• Initially, it was intended for specifying the structure of documents for the web– Its tags included <h1> <p> <ol> <ul> <li>

(See http://www.w3.org/History/19921103-hypertext/hypertext/WWW/MarkUp/Tags.html)

• These documents were then displayed using whatever rendering choices were made by the displaying program

Why XSL-FO? Some History (contd.)

• In the early days, there was some confusion

• People did not make the distinction between structure and style– Even Tim Berners-Lee made the mistake of

writing “Most of the tags are just style tags: this goes for the headings H1 to H6, the lists UL and OL with list elements LI, the glossary DL with elements DT and DD. ”

(See http://lists.w3.org/Archives/Public/www-talk/1991SepOct/0003.html)

Why XSL-FO? Some History (contd.)• This confusion caused the mistaken introduction of

rendering tags (and rendering attributes) into the language– For example: <b> <i> <tt> <font>

• Elimination of this confusion led to the introduction of Cascading Style Sheets and the deprecation of rendering tags and attributes

• It is now recognized that there should be a sharp distinction between the specification of structure and of rendering

• This distinction was already recognized by the time that XML was developed

Why XSL-FO? Some History (contd.)• The structure/rendering distinction is reflected in

the separation between XML and XSL• XML is used for specifying document structure• XSL is used for specifying document rendering• The W3 specification for XSL can be found here

http://www.w3.org/TR/xsl/

Why XSL-FO? Some History (contd.)• XSLT is able to do only part of the job of rendering XML

documents

• XSLT is for specifying how to analyse the structure of an XML document in order to compute the appropriate rendering of the document

• But XSLT must be complemented by a second notation in which we can specify the desired rendering

• We have seen that HTML is sometimes used as the second notation

• However, XSL Formatting Objects (XSL-FO) is the more general notation for specifying the desired rendering

Why XSL-FO? Some History (contd.)• It is common for XSLT to map XML documents

into HTML documents• This is because HTML has a rendering

semantics• However, HTML allows us to render XML

documents only as web pages– using browsers as the rendering engines

• Frequently, we need to render XML as other kinds of documents, including– PDF files, – Image files

• We need another notation which can be used to specify the rendering of PDF files and images

Why XSL-FO? Some History (contd.)• XSL has two parts

– XSLT can be used to analyse the structure of an XML document, in order to generate a document in some other notation

– XSL-FO is one such other notation

• XSL-FO is designed specifically for the purpose of describing the layout of documents– In this sense, its purpose is a little like that of CSS,– However, XSL-FO is quite different from CSS

• A layout description given in XSL-FO can be used to generate a growing variety of documents, including– PDF files, – Image files

XSL-FO is an XML application-specific language

• Every XSL-FO specification must be well-formed XML• For technical reasons, it is not possible to have a

comprehensive DTD for XSL-FO – However, an unofficial DTD is here http://www.cs.ucc.ie/j.bowen/usefulResources/fo2000.dtd.html

• Warning: this unofficial DTD was written by somebody from a company which produces a commercial FO processor program called XEP

• The unofficial DTD contains some commercial extensions which are associated with the namespace

http://www.renderx.com/XSL/Extensions• These extensions are identified in the DTD by use of the

prefix rx:

http://www.cs.ucc.ie/j.bowen/usefulResources/fo2000.dtd.html

XSL-FO is an XML application-specific language

• The namespace for XSL-FO ishttp://www.w3.org/1999/XSL/Format

• The prefix used is fo• The root element in XSL-FO has the tag name root• The declaration for this element in the unofficial DTD is

<!ELEMENT fo:root (fo:layout-master-set,

fo:declarations?,fo:page-sequence+)>

<!ATTLIST fo:root xmlns:fo CDATA #REQUIRED>

• Thus, the root element is of the form<fo:root

xmlns:fo="http://www.w3.org/1999/XSL/Format"> …

</fo:root>

How do we use XSL-FO?

First, let's revisit how we used XSLT to view XML files in

browsers

A reminder: viewing XML in a web browser

• The browser requests an XML document

• The XML document refers to an XSLT stylesheet– The browser then requests

the stylesheet

• The browser's XSLT Engine generates HTML from XML+XSLT

• The browser's HTML engine renders the HTML in the browser window

Using a browser's XSLT engine to generate HTML from XML ...

<?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="/"> <html><head><title>Greetings</title></head> <body><xsl:apply-templates select="./names/name"/></body></html> </xsl:template> <xsl:template match="name"> <p>Hello, <xsl:value-of select="."/>!</p> </xsl:template></xsl:stylesheet>

... Then rendering the HTML with the browser's HTML engine

<?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="/"> <html><head><title>Greetings</title></head> <body><xsl:apply-templates select="./names/name"/></body></html> </xsl:template> <xsl:template match="name"> <p>Hello, <xsl:value-of select="."/>!</p> </xsl:template></xsl:stylesheet>

What happens if we try the same thing with XSL-FO as we

just did with HTML?

Generating XSL-FO from XML

<?xml version="1.0"?><xsl:stylesheet version="1.0"xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format"> <xsl:output method="xml" indent="yes"/> <xsl:template match="/"> <fo:root><fo:layout-master-set><fo:simple-page-master master-name="A4-portrait" page-height="29.7cm" page-width="21.0cm"

margin="2cm"><fo:region-body/></fo:simple-page-master></fo:layout-master-set><fo:page-sequence master-reference="A4-portrait"><fo:flow flow-name="xsl-region-body"><xsl:apply-templates select="./names/name"/></fo:flow></fo:page-sequence></fo:root>

</xsl:template> <xsl:template match="name"><fo:block>Hello, <xsl:value-of select="."/>!</fo:block> </xsl:template></xsl:stylesheet>

How is the resultant XSL-FO rendered in the browser?

<?xml version="1.0" encoding="UTF-8"?>

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">

<fo:layout-master-set><fo:simple-page-master margin="2cm" page-width="21.0cm" page-height="29.7cm" master-name="A4-portrait"><fo:region-body/></fo:simple-page-master></fo:layout-master-set><fo:page-sequence master-reference="A4-portrait">

<fo:flow flow-name="xsl-region-body">

<fo:block> Hello, Tom! </fo:block>

<fo:block> Hello, Dick! </fo:block>

<fo:block> Hello, Harry! </fo:block>

</fo:flow></fo:page-sequence></fo:root>


• The browser cannot render XSL-FO










• The browser cannot render XSL-FO• The fo: tags are simply ignored










• The browser cannot render XSL-FO• The fo: tags are simply ignored• We just see the included text









What went wrong?

• The problem is that web browsers do not have engines for rendering XSL-FO

• Instead, web browsers have engines for rendering HTML

So how do we render XSL-FO?

So how do we render XSL-FO?

• We need a different kind of program

• We need a program which contains an FO engine

• These programs are called FO processors

• Usually they also contain an XSLT engine

• They can generate various kinds of output, including PDF and image files

Generating XSL-FO from XML and then rendering the XSL-FO

• Apache FOP is a commonly-used FO processor• fop contains both an XSLT engine and an FO engine• Example usage on the cs1 server:

cs1> fop -xml names2.xml -xsl names2.xsl -pdf names2.pdf• This example command tells fop to apply an XSL

stylesheet to an XML document and output a PDF file• The XML file need/should not contain an xml-

stylesheet instruction

Starting to write XSL-FO

First stage of an XSLT stylesheet for generating XSL-FO from XML

<?xml version="1.0"?><xsl:stylesheet version="1.0"xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format"> <xsl:output method="xml" indent="yes"/> <xsl:template match="/"> <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">

… </fo:root> </xsl:template></xsl:stylesheet>

Contents of the fo:root element• Element declaration:

<!ELEMENT fo:root (

fo:layout-master-set,

fo:declarations?,

fo:page-sequence+ )>

• Thus, the minimum contents of an fo:root element are:• fo:layout-master-set a description of the page layouts

that are used in the document being specified• fo:page-sequence+ a set of specifications for one or

more sequences of actual pages in the document

Minimum fo:root element• Example XSL-FO document

<?xml version="1.0"?>

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> <fo:layout-master-set> … </fo:layout-master-set>

<fo:page-sequence … > … </fo:page-sequence></fo:root>

The layout-master-set• Declaration in the unofficial DTD is

<!ELEMENT fo:layout-master-set

( fo:page-sequence-master*, fo:simple-page-master,

( fo:simple-page-master | fo:page-sequence-master )* ) >

• Thus, the layout-master-set must contain at least one element of type fo:simple-page-master

• Example XSL-FO document<?xml version="1.0"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">

<fo:layout-master-set> <fo:simple-page-master master-name=“…"> … </fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence … > … </fo:page-sequence></fo:root>

Page sequences refer to page masters• Each page sequence must refer to a page master



<fo:layout-master-set> <fo:simple-page-master master-name="someName"> … </fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence master-reference="someName"> … </fo:page-sequence>

</fo:root>

How pages are modelled in XSL-FO

• In the XSL-FO page model, a page in the document being specified contains several areas

• The part of the page where the content will be placed is called the page-reference-area

• There are four margins around the page-reference-area

• These margins can be zero

How pages are modelled in XSL-FO (contd.)• The page-reference-area can

be divided into five regions• Only the region-body is

required• Most content will be placed in

the region-body• The other regions may or may

not be present• If the other regions are not

present, the regions-body will be the same size as the page-reference-area

How pages are modelled in XSL-FO (contd.)• Unofficial DTD declaration for fo:simple-page-master is

<!ELEMENT fo:simple-page-master

(fo:region-body,fo:region-before?,

fo:region-after?,fo:region-start?,fo:region-end?)>

How pages are modelled in XSL-FO (contd.)• Unofficial DTD declaration for fo:simple-page-master is


(fo:region-body,fo:region-before?,

fo:region-after?,fo:region-start?,fo:region-end?)>

<!ATTLIST fo:simple-page-master

%margin-properties-CSS;

master-name CDATA #REQUIRED

page-height CDATA #IMPLIED

page-width CDATA #IMPLIED

media-usage CDATA #IMPLIED

size CDATA #IMPLIED reference-orientation

( 0 | 90 | 180 | 270 | -90 | -180 | -270 | 0deg | 90deg | 180deg | 270deg | -90deg| - 180deg | -270deg | inherit ) #IMPLIED

writing-mode ( lr-tb | rl-tb | tb-rl | lr | rl | tb | inherit ) #IMPLIED >

How pages are modelled in XSL-FO (contd.)

• The definition, in the unofficial DTD, of the CSS-type margin properties is

How pages are modelled in XSL-FO (contd.)

• The definition, in the unofficial DTD, of the CSS-type margin properties is

<!ENTITY % margin-properties-CSS "

margin CDATA #IMPLIED

margin-bottom CDATA #IMPLIED

margin-left CDATA #IMPLIED

margin-right CDATA #IMPLIED

margin-top CDATA #IMPLIED

margin-after CDATA #IMPLIED

margin-start CDATA #IMPLIED

margin-end CDATA #IMPLIED

margin-before CDATA #IMPLIED ">

Example XSL-FO document<?xml version="1.0"?>

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> <fo:layout-master-set>

<fo:simple-page-master master-name="myPageType" page-height="29.7cm" page-width="21.0cm" margin="2cm">

<fo:region-body/>

</fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence master-reference="myPageType"> ...... </fo:page-sequence></fo:root>

The region-body element• Declaration in the unofficial DTD is

<!ELEMENT fo:region-body EMPTY>

<!ATTLIST fo:region-body

%region-properties;


column-count CDATA #IMPLIED

column-gap CDATA #IMPLIED >

The region-body element• Declaration in the unofficial DTD is

<!ELEMENT fo:region-body EMPTY>

<!ATTLIST fo:region-body

%region-properties;


column-count CDATA #IMPLIED

column-gap CDATA #IMPLIED ><!ENTITY % region-properties "

%border-padding-background-properties;

%area-properties;

region-name CDATA #IMPLIED">

<!ENTITY % area-properties " clip CDATA #IMPLIED overflow ( visible | hidden | scroll | auto | error-if-overflow | inherit ) #IMPLIED display-align ( auto | before | center | after | inherit ) #IMPLIED reference-orientation ( 0 | 90 | 180 | 270 | -90 | -180 | -270 | 0deg | 90deg | 180deg | 270deg | -90deg | -180deg | -270deg | inherit ) #IMPLIED writing-mode ( lr-tb | rl-

tb | tb-rl | lr | rl | tb | inherit ) #IMPLIED ">

The fo:page-sequence element• Declaration in the unofficial DTD

<!ELEMENT fo:page-sequence (fo:title?, fo:static-content*, fo:flow)><!ATTLIST fo:page-sequence id CDATA #IMPLIED master-name CDATA #REQUIRED initial-page-number CDATA #IMPLIED force-page-count ( auto | even | odd | end-on-even | end-on-odd | no-force | inherit) #IMPLIED format CDATA #IMPLIED letter-value ( auto | alphabetic | traditional ) #IMPLIED grouping-separator CDATA #IMPLIED grouping-size CDATA #IMPLIED %inheritable-properties; >

• Thus a minimal fo:page-sequence must have a master-name and must contain an fo:flow

The fo:flow element• Declaration in the unofficial DTD

<!ELEMENT fo:flow ( %blocks; )+ >

<!ATTLIST fo:flow %flow-properties; >

<!ENTITY % blocks " %basic-blocks; | %out-of-lines; | %wrappers; ">

<!ENTITY % flow-properties "

id CDATA #IMPLIED

flow-name CDATA #REQUIRED

%inheritable-properties; ">

<!ENTITY % basic-blocks " fo:block | fo:block-container | fo:table-

and-caption | fo:table | fo:list-block "> • Thus a minimal fo:flow must have a flow-name (which

specifies the region in which its content will be placed) and must contain at least one blocks entity

• The simplest instance of blocks is an fo:block element

The fo:block element• Declaration in the unofficial DTD

<!ELEMENT fo:block

( #PCDATA

| fo:initial-property-set

| %basic-inlines;

| %basic-blocks;

| %out-of-lines;

| %wrappers; )* >

<!ATTLIST fo:block %block-properties;>

• The simplest content for an fo:block element is just some text

Example XSL-FO document<?xml version="1.0"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> <fo:layout-master-set> <fo:simple-page-master master-name="myPageType" page-height="29.7cm" page-width="21.0cm" margin="2.0cm"> <fo:region-body/> </fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence master-reference="myPageType"> <fo:flow flow-name="xsl-region-body"> <fo:block>Hello world</fo:block> </fo:flow> </fo:page-sequence></fo:root>

Specifying lengths in XSL-FO

• A length in XSL-FO is written as a real number followed by a unit qualification

• Section 5.9.13 of the XSL specificationhttp://www.w3.org/TR/xsl/#d0e5752

lists the allowable units as• cm• mm• in• pt (1/72 in)• pc (12 pt)• px• em (size of capital M in current font size)

The fop processor accepts XSL-FO files as input

• Place the text on the previous slide in a file called demo.fo

• Then run the command

fop -fo demo.fo -pdf demo.pdf

• A pdf file will be generated

The fop processor can output several types of file

• Assume that demo.fo contains the source code shown on the previous slide

• The command fop -fo demo.fo -png demo.png

will output the document as png image

• To see the full range of file types that can be generated, run the command

fop -out list

Using XSLT to generate XSL-FO• Suppose we have the

XML file shown • Suppose we want to

generate the XSL-FO for the PDF document shown

• Our XSLT program must – generate the "boiler-plate"

XSL-FO when it finds the root node

– and generate a sentence when it finds each country node

• We will need two templates

The "boiler-plate" template<xsl:template match="/">

<fo:root>

<fo:layout-master-set>

<fo:simple-page-master master-name="A4-portrait"

page-height="29.7cm" page-width="21.0cm" margin="2cm">

<fo:region-body/>

</fo:simple-page-master>

</fo:layout-master-set>

<fo:page-sequence master-reference="A4-portrait">


<xsl:apply-templates select="./countries/country"/>

</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>

The country template

<xsl:template match="country">

<fo:block>

<xsl:value-of select="."/> is a country.

</fo:block>

</xsl:template>

The complete XSLT stylesheet<?xml version="1.0"?>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

xmlns:fo="http://www.w3.org/1999/XSL/Format">

<xsl:output method="xml" indent="yes"/>

<xsl:template match="/">

<fo:root>




<fo:region-body/>






</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>


<fo:block>

<xsl:value-of select="."/> is a country.

</fo:block>

</xsl:template>

</xsl:stylesheet>

Using FOP• Assume the XML file is called countries.xml• Assume the XSLT file is called countries.xsl• We can generate the PDF file thus

fop -xml countries.xml -xsl countries.xsl -pdf countries.pdf

• We can see the XSL-FO thus

fop -xml countries.xml -xsl countries.xsl -foout countries.fo

The XSL-FO that was generated<?xml version="1.0" encoding="UTF-8"?>



<fo:simple-page-master margin="2cm" page-width="21.0cm"

page-height="29.7cm" master-name="A4-portrait">

<fo:region-body/>





<fo:block>France is a country.</fo:block>

<fo:block>Germany is a country.</fo:block>

<fo:block>Ireland is a country.</fo:block>

</fo:flow>

</fo:page-sequence>

</fo:root>

Block attributes• In the unofficial DTD, many attributes are defined for

blocks


blocks• We will consider just a a few at this stage <!ATTLIST fo:block %block-properties;> <!ENTITY % block-properties " id CDATA #IMPLIED %inheritable-properties; "> <!ENTITY % inheritable-properties " color CDATA #IMPLIED relative-align ( before | baseline | inherit ) #IMPLIED span ( none | all | inherit ) #IMPLIED %accessibility-properties; %absolute-or-relative-position-properties;

%border-padding-background-properties; %border-precedence-properties; %aural-properties; %box-size-properties; %margin-properties-inline; %area-properties; %area-alignment-properties-inline; %character-properties; %table-properties; %list-properties; %float-properties; %line-related-properties; %leader-properties; %keeps-and-breaks-properties-block; %hyphenation-properties-block;

%visibility-properties; ">


blocks• We will consider just a a few at this stage <!ATTLIST fo:block %block-properties;> <!ENTITY % block-properties " id CDATA #IMPLIED %inheritable-properties; "> <!ENTITY % inheritable-properties " color CDATA #IMPLIED relative-align ( before | baseline | inherit ) #IMPLIED span ( none | all | inherit ) #IMPLIED %accessibility-properties; %absolute-or-relative-position-properties;

%border-padding-background-properties; %border-precedence-properties; %aural-properties; %box-size-properties;

%margin-properties-inline; %area-properties; %area-alignment-properties-inline; %character-properties; %table-properties; %list-properties; %float-properties; %line-related-properties; %leader-properties; %keeps-and-breaks-properties-block; %hyphenation-properties-block;


A diagram of some block sttributes

Block attributes (contd.)• Like a <p> or a <div> in

HTML, a <block> in XSL-FO specifies that some content should be displayed in a rectangular area that is visually separated by a new line

• Like a CSS area, an XSL-FO block area has attributes that we can control with CSS-like expressions

• However, XSL-FO provides many more attributes than CSS

• Before surveying all the attributes, let’s look at an example use

Example use of block attributes in XSLT<?xml version="1.0"?>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"




<fo:root>




<fo:region-body/>






</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>


<fo:block border-width="3mm" border-color="red" border-style="solid" space-before="5mm"> <xsl:value-of select="."/> is a country.

</fo:block>

</xsl:template>

</xsl:stylesheet>

Example contd: the XSL-FO generated<?xml version="1.0" encoding="UTF-8"?>



<fo:simple-page-master margin="2cm" page-width="21.0cm"

page-height="29.7cm" master-name="A4-portrait">

<fo:region-body/>





<fo:block space-before="5mm" border-style="solid" border-color="red" border-width="3mm"> France is a country.</fo:block>

<fo:block space-before="5mm" border-style="solid" border-color="red" border-width="3mm">Germany is a country.</fo:block>

<fo:block space-before="5mm" border-style="solid" border-color="red" border-width="3mm">Ireland is a country.</fo:block>

</fo:flow>

</fo:page-sequence>

</fo:root>

PDF based on new XSL-FO output

Block area attributes (page 1)• Block space-before

and space-after– These specify

minimum, optimum and maximum amounts of space that must be separate a block from the blocks just before and after the current block

– Will be considered in detail later

Block area attributes (page 2)• Block Margin

– margin – margin-top – margin-bottom – margin-left – margin-right

Block area attributes (page 3)• Block Border

– Border style attributes:• Overall border

– border-style

• Side borders (Absolute Orientation) – border-top-style – border-bottom-style – border-left-style – border-right-style

• Sides borders (Orientation relative to writing-mode) – border-before-style (sometimes same as border-top) – border-after-style (sometimes same as border-bottom) – border-start-style (sometimes same as border-left) – border-end-style (sometimes same as border-right)

– Possible valuesnone | dotted | dashed | solid | double | groove | ridge

Block area attributes (page 4)• Block Border (contd.)

– Border color attributes:• border-color • border-before-color • border-after-color • border-start-color • border-end-color • border-top-color (sometimes same as border-before) • border-bottom-color (sometimes same as border-after) • border-left-color (sometimes same as border-start) • border-right-color (sometimes same as border-end)

– Possible values• any predefined colour name• rgb(0-255,0-255,0-255)


– Border width attributes:• border-width • border-before-width • border-after-width • border-start-width • border-end-width • border-top-width (sometimes same as border-before) • border-bottom-width (sometimes same as border-after) • border-left-width (sometimes same as border-start) • border-right-width (sometimes same as border-end)


– Block Padding• padding • padding-before • padding-after • padding-start • padding-end • padding-top (sometimes same as padding-before) • padding-bottom (sometimes same as padding-after) • padding-left (sometimes same as padding-start) • padding-right (sometimes same as padding-end)


– Block Background• background-color • background-image • background-repeat • background-attachment (scroll or

fixed)

Specifying versus constraining properties• Some properties, for example border-color, can specify

an exact value which will appear in the output document• However, the space-before and space-after properties

can only constrain the set of possible values that will appear in the output document without being able to specify the exact value that will appear– The actual value will depend on the way that the FO engine

handles conflicting constraints

• We will now consider these two properties in some detail

The space-before and space-after properties

Example XML document

• This is ex.xml. It contains a text element, which contains ten paragraph elements:


<text>

<paragraph> This is a sentence in paragraph1. This is a sentence. ... This is a sentence.

</paragraph>

....

<paragraph> This is a sentence in paragraph10. This is a sentence. ... This is a sentence.

</paragraph>

</text>

• The next slide contains ex1.xsl, an XSLT stylesheet for processing this XML

ex1.xsl generates a header block and paragraph blocks<?xml version="1.0" encoding="utf-8"?>

<xsl:stylesheet version="1.0"

xmlns:xsl="http://www.w3.org/1999/XSL/Transform"




<fo:root> <fo:layout-master-set> <fo:simple-page-master master-name="A4-portrait"

page-height="29.7cm" page-width="21.0cm" margin="2cm"><fo:region-body/></fo:simple-page-master> </fo:layout-master-set>



<fo:block font-size="50pt" border="solid blue 3mm">Some text</fo:block>

<xsl:apply-templates select="./text/paragraph"/>

</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>

<xsl:template match="paragraph">

<fo:block border="red solid 3mm"> <xsl:value-of select="."/></fo:block>

</xsl:template>

</xsl:stylesheet>

Result of processing XML with ex1.xsl• Result is a two page PDF file

fop -xml ex.xml -xsl ex1.xsl -pdf ex1.pdf • Notice that the sixth

paragraph is split across the page boundary

• The block specifications do not require any space between the blocks

• Header block specification <fo:block font-size="50pt"

border="solid blue 3mm">

Some text

</fo:block>

• Paragraph block specification

<fo:block border="red solid 3mm">

<xsl:value-of select="."/>

</fo:block>

ex2.xsl Preventing paragraph blocks from crossing page boundaries

<?xml version="1.0" encoding="utf-8"?>






<fo:root>

<fo:layout-master-set> <fo:simple-page-master master-name="A4-portrait"






</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>


<fo:block border="red solid 3mm" keep-together.within-page="always">


</fo:block>

</xsl:template>

</xsl:stylesheet>

Result of processing XML with ex2.xsl• The entire sixth paragraph is now on the second page

The keep-together property• This property has three components, referring to three different

contexts– within-line, – within-column, – within-page

• Possible values– auto, which imposes no keep-together requirement– always, which always keeps the formatting object keep-together– <some integer>, which imposes a keep-together requirement of

the specified strength, with bigger integers being stronger if there is ever a conflict

• A description of how conflicts are resolved is given athttp://www.w3.org/TR/xsl/#keepbreak

ex3.xsl Requiring space-before the paragraph blocks







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>


<fo:block border="red solid 3mm" keep-together.within-page="always"

space-before="4cm" >


</fo:block>

</xsl:template>

</xsl:stylesheet>

Result of processing XML with ex3.xsl

• The output now occupies 4 pages in PDF• There is 4 cm of space before each paragraph

– except for a paragraph at the start of a page

• Why is there no 4 cm space before a paragraph at the start of a page?

Space specifiers• The space-before property specifies the space required before the

area generated by an XSL-FO object• The space-after property specifies the space required after the area

generated by an XSL-FO object• Each space-specifier has five components, with the default values

indicated in parentheses– minimum (0 pt)

– optimum (0 pt)

– maximum (0 pt)

– conditionality (discard)

– precedence (0)

• A space specifier like space-before="4cm" is actually a shorthand for space-before.minimum="4cm"

space-before.optimum="4cm"

space-before.maximum="4cm"

space-before.conditionality="discard"

space-before.precedence="0"

The conditionality component of space specifiers• Even if a space-specifier exists for an XSL-FO object, the space

may sometimes not be rendered• A space specifier is normally used to generate a space between the

area generated by an XSL-FO object and the nearest visible mark on the page before of after that area

• The nearest visible mark may come from– the content of a non-empty content rectangle

– a non-zero border • the border need not belong to the next or previous area• it could belong to an embracing block

– some padding (because padding may contain background)• the padding need not belong to the next or previous area• it could belong to an embracing block

• If the area generated by an XSL-FO object is at the top of a page, there is no visible mark on the page before the area, so a space-before could be discarded

• Similarly, if the area generated is at the bottom of a page, a space-after could be discarded

Conditionality component of space specifiers (contd.) • The conditionality component of a space specifier can have one of

two values:discard

• this means that the space-before/after is not required if there is no visible mark on the page before/after the XSL-FO object which has this space specifier

retain• this means that the space-before/after must always be generated, even if

there is no visible mark on the page before/after the XSL-FO object which has this space specifier

ex4.xsl Always requiring space-before the paragraph blocks







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>


<fo:block border="red solid 3mm" keep-together.within-page="always"

space-before="4cm" space-before.conditionality="retain" >


</fo:block>

</xsl:template>

</xsl:stylesheet>


• Now, there is a 4 cm space before each paragraph at the start of a page

Precedence of space specifiers• Sometimes, when two boxes follow each other, the first box may

have a space-after and the second box may have a space-after• The formatting program does not automatically produce both of

these spaces– the result would almost certainly be too much space between the

boxes• Instead, the formatting program uses space precedence rules to

decide which space to generate on the page• The value of the precedence component for a space specifier can

be either– <some integer>

– or the word force

• By default, the precedence for a space specifier is 0• The space precedence rules are on the next slide

Space precedence rules• When two space specifiers are in conflict, the following rules are

used• If either space precedence is force, the formatting program will

generate a space equal to the sum of all specifiers with a precedence of force

• Otherwise, the formatting program will use the numeric space precedences to decide what to do

• If the specifiers have different numeric precedences, the specifier with the higher precedence is used

• If the specifiers have the same numeric precedence, – the formatting program will generate a space somewhere in the range

[smaller-minimum, bigger maximum]

– initially, the formatting program will try to generate a space equal to the bigger-maximum

ex5.xsl A force precedence wins







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>


<fo:block border="red solid 3mm"

space-before="4cm" space-before.precedence="force"

space-after="8cm" space-after.precedence="4" >


</fo:block>

</xsl:template>

</xsl:stylesheet>


• The 4cm space-before, with precedence=force beats the 8cm space-after

• There is a 4 cm space between each pair of paragraphs

ex6.xsl Two neighbouring specifiers with precedence=force







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



space-before="4cm" space-before.precedence="force"

space-after="8cm" space-after.precedence="force" >


</fo:block>

</xsl:template>

</xsl:stylesheet>


• Both the 4cm space-before and 8 cm space-after have precedence=force

• Each pair of paragraphs on the same page are separated by 12 cm

ex7.xsl Two neighbouring specifiers with different numeric precedences







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



space-before="4cm" space-before.precedence="4"



</fo:block>

</xsl:template>

</xsl:stylesheet>


• The 4cm space-before, with precedence=4, is beaten by the 8 cm space-after with precedence=5


ex8.xsl Two neighbouring specifiers with different numeric precedences







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>






</fo:block>

</xsl:template>

</xsl:stylesheet>


• The 4cm space-before, with precedence=5, beats by the 8 cm space-after with precedence=4


ex9.xsl Two neighbouring specifiers with equal numeric precedences







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>






</fo:block>

</xsl:template>

</xsl:stylesheet>


• Both the 4cm space-before and the 8cm space-after have precedence=4

• The actual space must be in the interval [4,8]

• The larger optimum is 8cm, so it is tried

• It is possible everywhere, so it is used everywhere

A digression: the keep-with-previous and keep-with-next properties

• Each of these properties has three components, referring to three different contexts– within-line, – within-column, – within-page

• Possible values– auto, which imposes no keep-with-previous/next requirement– always, which always keeps the formatting object with the

previous/next object– <some integer>, which imposes a keep-with-previous/next

requirement of the specified strength, with bigger integers being stronger if there is ever a conflict

• A description of how conflicts are resolved is given athttp://www.w3.org/TR/xsl/#keepbreak

ex10.xsl Generating a space different from the optimum







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



keep-together.within-page="always" keep-with-previous.within-page="5"


space-after.minimum="5cm" space-after.optimum="12cm" space-after.maximum="12cm" space-after.precedence="4" >


</fo:block>

</xsl:template>

</xsl:stylesheet>


• Both the 4cm space-before and the 5-12cm space-after have precedence=4

• The actual space must be in the interval [4,12]

• The larger optimum is 12cm, so it is tried everywhere

• However, the keep-together and keep-with-previous requirements mean that the optimum is possible only on the last page

• On the earlier pages, a smaller space is generated

ex11.xsl Using a negative space-before to cause overwriting







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



space-before="-8mm" > <xsl:value-of select="."/>

</fo:block>

</xsl:template>

</xsl:stylesheet>


• Each paragraph block, except that for paragraph 8, overwrites part of the previous block

ex12.xsl Conflict between negative and positive space







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



space-before.maximum="-8mm" space-after.optimum="4mm" > <xsl:value-of select="."/>

</fo:block>

</xsl:template>

</xsl:stylesheet>


• The first paragraph is moved back 8mm, because there is no space conflict

• However, when a sequence of two paragraphs are on the same page, there is a space conflict

• For space-before, max=-8mm forces minimum and optimum to be -8mm, because they cannot exceed the maximum

• For space-after, opt=4mm forces the max to be 4mm as well, because optimum cannot exceed maximum. Minimum is the default of 0.

• Space generated must be in range [smaller-min, bigger-max]; that is, in [-8mm,4mm]

• The bigger optimum, of 4mm is tried everywhere and can be used everywhere

ex13.xsl Another conflict between negative and positive space







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



space-before.maximum="-8mm" space-after.optimum="8cm" > <xsl:value-of select="."/>

</fo:block>

</xsl:template>

</xsl:stylesheet>


• The first paragraph is moved back 8mm, because there is no space conflict


• For space-before, max=-8mm forces minimum and optimum to be -8mm, because they cannot exceed the maximum

• For space-after, opt=8cm forces the max to be 8cm as well, because optimum cannot exceed maximum. Minimum is the default of 0.

• Space generated must be in range [smaller-min, bigger-max]; that is, in [-8mm,8cm]

• The bigger optimum, of 8cm is tried everywhere

• However, in all cases on the first page, a smaller value must be used

ex14.xsl Another conflict involving negative space







<fo:root>







</fo:flow>

</fo:page-sequence>

</fo:root>

</xsl:template>



space-before.maximum="-8mm" space-after.optimum="0mm" > <xsl:value-of select="."/>

</fo:block>

</xsl:template>

</xsl:stylesheet>

A problem: the result of processing XML with ex14.xsl• The processing by fop does not agree

with what appears to be the rules

• The first paragraph should be moved back 8mm, because there is no space conflict


• For space-before, max=-8mm should force minimum and optimum to be -8mm, because they cannot exceed the maximum

• For space-after, opt=0mm should force the max to be 0mm as well, because optimum cannot exceed maximum. Minimum should be default of 0.

• Space generated should be in range [smaller-min, bigger-max]; that is, in [-8mm,0mm]

• The bigger optimum, of 0mm, should be tried everywhere

• However,

A problem: the result of processing XML with ex14.xsl• The processing by fop does not agree

with what appears to be the rules

• The first paragraph should be moved back 8mm, because there is no space conflict


• For space-before, max=-8mm should force minimum and optimum to be -8mm, because they cannot exceed the maximum

• For space-after, opt=0mm should force the max to be 0mm as well, because optimum cannot exceed maximum. Minimum should be default of 0.

• Space generated should be in range [smaller-min, bigger-max]; that is, in [-8mm,0mm]

• The bigger optimum, of 0mm, should be tried everywhere

• However, in all cases, -8mm is used

• Why? Dunno?

The Area Model

The Area Model• Almost everything in XSL-FO can be

regarded as being placed in a rectangular box on the page– the page itself is a box– the regions with the page are boxes– the blocks within a region are boxes– each block contains boxes for lines– lines contain boxes for text and inline areas

• This nesting of boxes is called the Area Model

Box directions• Earlier, it was said that

– border-before-color is sometimes the same as border-top-color, – border-after-color is sometimes the same as border-bottom-color, – border-start-color is sometimes the same as border-left-color,

– border-end-color is sometimes the same as border-right-color,

– etc.

• These statements use the word "sometimes", because whether "before" means the same as "top", and so on, depends on the directions in which content is being added to a box

• Content is added to a box using two directions, which will be illustrated on the next few slides– the block-progression direction– the inline-progression direction

Box directions for normal Western text• In normal Western documents, the block-progression direction is top-

to-bottom, so– before means the same as top– after means the same as bottom

Box directions for normal Western text• In normal Western documents, the inline-progression direction is left-

to-right, so– start means the same as left– end means the same as right

Box directions for Semitic languages

• In Semitic languages, the block-progression direction is the same as in Western languages: top-to-bottom

• However, the inline-progression direction is right-to-left, so– start means the same as right

– end means the same as left

One set of directions for Japanese

• Japanese can be written in various ways



• One possible way is to start at the top-right corner and write downwards– so the inline-progression direction is

top-to-bottom• so start means the same as top• so end means the same as bottom





• And then





• And then move to the left for the next column of characters





• And then move to the left for the next column of characters– so the block progression direction is

right-to-left• so before means the same as right• so after means the same as left

Writing-mode• The order in which a language appears on the page is called the

writing-mode • The writing-mode for English is left-to-right, top-to-bottom (lr-tb)• Writing mode affects the direction of block-progression and inline-

progression • We can change these directions by using a style property called

writing-mode• The values defined in the XSL-FO specification are

lr-tb | rl-tb | tb-rl | tb-lr | bt-lr | bt-rl | lr-bt | rl-bt | lr-alternating-rl-bt | lr-alternating-rl-tb | lr-inverting-rl-bt | lr-inverting-rl-tb | tb-lr-in-lr-pairs | lr | rl | tb

• The first letter-pair specifies the inline-progression direction• The second letter-pair specifies the block-progression direction• Not all of these writing modes are supported by all XSL-FO engines

– for example, tb-lr gives an error message in Apache FOP

• The next dew slides show some example usage

We can set writing-mode in the simple-page-master tag <?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">

<fo:layout-master-set><fo:simple-page-master margin="2cm" page-width="21.0cm" page-height="29.7cm" master-name="A4-portrait" writing-mode="rl-tb" ><fo:region-body/></fo:simple-page-master></fo:layout-master-set>

<fo:page-sequence master-reference="A4-portrait"><fo:flow flow-name="xsl-region-body"><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block></fo:flow></fo:page-sequence>

</fo:root>

Writing-mode example 1<fo:simple-page-master margin="2cm"

page-width="21.0cm" page-height="29.7cm"

master-name="A4-portrait" writing-mode="rl-tb" >

Writing-mode example 2<fo:simple-page-master margin="2cm"


master-name="A4-portrait" writing-mode="tb-rl" >

Page regions and box directions

A reminder: regions of a page

• Earlier, we saw that XSL-FO treats a page as a collection of regions

• But region-body is the only required region

• If we want to use the optional regions,

we must define them in the order specified in this DTD element definition


(fo:region-body,

fo:region-before?,

fo:region-after?,

fo:region-start?,

fo:region-end?

)>

The location of the regions

• The regions do not always appear on the page in the positions show here

• The locations shown here are simply those that the regions have in normal Western documents

Location of the optional regions in normal Western layout

• In normal Western documents, the writing-mode is lr-tb

• So before/after/start/end have the meanings shown in this image







<fo:simple-page-master margin="2cm"

page-width="21.0cm"

page-height="29.7cm"

master-name="A4-portrait"

writing-mode="lr-tb" >

<fo:region-body margin="2cm"/>

<fo:region-before extent="1.5cm"

background-color="green" />

<fo:region-after extent="1.5cm"

background-color="brown" />

<fo:region-start extent="1.5cm"

background-color="blue" />

<fo:region-end extent="1.5cm"

background-color="red" />


Location of the optional regions in normal Semitic layout

• In normal Semitic documents, the writing-mode is rl-tb

• So before and after have the same meanings as in Western documents

• But the meanings of start and end are the reverse of their meaning in Western style documents




• But the meanings of start and end are the reverse of their meaning in Western style documents– the blue and red regions are

reversed from the previous slide




• But the meanings of start and end are the reverse of their meaning in Western style documents– the blue and red regions are

reversed from the previous slide<fo:simple-page-master margin="2cm"



writing-mode="rl-tb" >











Western versus Semitic layout

• The before (green) and after (brown) regions are in the same place• But the start (blue) and end (red) regions are reversed

Apache FOP cannot handle optional regions in Japanese layout

• We have seen that Japanese sometimes uses writing-mode=tb-rl

• Apache FOP seems able to handle the text placement

• But it does not seem able to handle the placement of the optional before/after/start/end regions




writing-mode="tb-rl" >











Margins and regions

body-region margins are measured from ...

• When using the optional regions,

it is essential to remember that margins for the content of

the region-body

are actually measured from

the outside edges of

body-region margins are measured from ...

• When using the optional regions,

it is essential to remember that margins for the content of

the region-body

are actually measured from

the outside edges of

the page-reference-area

Margins and regions, Example 1<fo:simple-page-master margin="0cm" …><fo:region-body margin="1cm"/><fo:region-before extent="0.5cm" background color="green" /><fo:region-after extent="0.5cm" background-color="yellow" /><fo:region-start extent="0.5cm" background-color="blue" /><fo:region-end extent="0.5cm“ background-color=“red" />

Margins and regions, Example 1<fo:simple-page-master margin="0cm" …><fo:region-body margin="1cm"/><fo:region-before extent="0.5cm" background color="green" /><fo:region-after extent="0.5cm" background-color="yellow" /><fo:region-start extent="0.5cm" background-color="blue" /><fo:region-end extent="0.5cm“ background-color=“red" />• The simple-page-master margin

surrounds the page-reference-area, which is divided into five regions



• In this example we have a zero margin in the simple-page-master– so, here, the page-reference-area

covers the entire page




covers the entire page• The margin for the region-body pushes

the content in from the outer edge of the page-reference-area




covers the entire page• The margin for the region-body pushes

the content in from the outer edge of the page-reference-area

• The reason there is white space above and to the left of the content is that the region-body margin is wider than region-before and region-start

Margins and regions, Example 2

<fo:simple-page-master margin=“2cm" …><fo:region-body margin="1cm"/><fo:region-before extent="0.5cm background color="green" /><fo:region-after extent="0.5cm“ background-color="yellow" /><fo:region-start extent="0.5cm" background-color="blue" /><fo:region-end extent="0.5cm“ background-color=“red" />


<fo:simple-page-master margin=“2cm" …><fo:region-body margin="1cm"/><fo:region-before extent="0.5cm background color="green" /><fo:region-after extent="0.5cm“ background-color="yellow" /><fo:region-start extent="0.5cm" background-color="blue" /><fo:region-end extent="0.5cm“ background-color=“red" />• The page-reference area is smaller than

the page, because the margin in the simple-page-master is greater than zero


<fo:simple-page-master margin=“2cm" …><fo:region-body margin="1cm"/><fo:region-before extent="0.5cm background color="green" /><fo:region-after extent="0.5cm“ background-color="yellow" /><fo:region-start extent="0.5cm" background-color="blue" /><fo:region-end extent="0.5cm“ background-color=“red" />• The page-reference area is smaller than

the page, because the margin in the simple-page-master is greater than zero

• The content is 3cm inside the edge of the page because

– the simple-page-master margin is 2cm– the region-body also has a margin, of

1cm


• Margins for region-body must exceed the extents of the region-before, region-after, region-start and region-end

• If not, the content of the region-body will appear in these other regions

<fo:simple-page-master margin=“2cm" …><fo:region-body margin="1cm"/><fo:region-before extent=“1.5cm background color="green“ /><fo:region-after extent=“1.5cm“ background-color="yellow“ /><fo:region-start extent=“1.5cm" background-color="blue“ /><fo:region-end extent=“1.5cm“ background-color=“red“ />

More on writing-mode

Putting writing-mode in a different place

• We have specified writing-mode as an attribute of a simple-page-master element




writing-mode="tb-rl" >

• However, instead, we could specify it as an attribute of the region-body element



master-name="A4-portrait" >

<fo:region-body margin="2cm" writing-mode="tb-rl" /><fo:region-before extent="1.5cm" background-color="green"/>

<fo:region-after extent="1.5cm" background-color="yellow"/>

<fo:region-start extent="1.5cm" background-color="blue"/>

<fo:region-end extent="1.5cm" background-color="red"/>


Writing-mode for region-body, Example 1

• Notice that setting writing-mode in the region-body does not affect the placement of the other regions• unlike setting writing-

mode in the simple-page-master, which did affect all the regions

<fo:region-body margin="2cm“ writing-mode="rl-tb“ /><fo:region-before extent="1.5cm" background-color="green"/><fo:region-after extent="1.5cm" background-color="yellow"/><fo:region-start extent="1.5cm" background-color="blue"/><fo:region-end extent="1.5cm" background-color="red"/>

Writing-mode for region-body, Example 2

<fo:region-body margin="2cm“ writing-mode="tb-rl“ /><fo:region-before extent="1.5cm" background-color="green"/><fo:region-after extent="1.5cm" background-color="yellow"/><fo:region-start extent="1.5cm" background-color="blue"/><fo:region-end extent="1.5cm" background-color="red"/>

Where can writing-mode be specified?

• The XSL-FO specification says that a writing-mode can be specified for the following elements:

fo:simple-page-master,

fo:region-*,

fo:table,

fo:block-container,

fo:inline-container

• However, not all of these element types are supported by all FO processors

– For example, as of 2010, Apache FOP does not support fo:inline-container

• However, let's use it in fo:block-container

Using writing-mode in fo:block-container



<fo:layout-master-set><fo:simple-page-master margin="2cm"

page-width="21.0cm" page-height="29.7cm" master-name="A4-portrait">

<fo:region-body margin="2cm" writing-mode="lr-tb" /> </fo:simple-page-master>




<fo:block-container writing-mode="lr-tb">

<fo:block>Hello, Tom!</fo:block>

<fo:block>Hello, Dick!</fo:block>

</fo:block-container>

<fo:block-container writing-mode="rl-tb">

<fo:block>Hello, Harry!</fo:block>

<fo:block>Hello, Mick!</fo:block>


</fo:flow></fo:page-sequence>

</fo:root>

Using writing-mode in fo:block-container

















</fo:flow></fo:page-sequence>

</fo:root>

We can, of course, specify other attributes in fo:block-container









<fo:block-container writing-mode="lr-tb" color="red">




<fo:block-container writing-mode="rl-tb" color="blue">



</fo:block-container></fo:flow>

</fo:page-sequence>

</fo:root>

Now we can see why XSL-FO provides before/start/end/after


• They let us specify style properties without worrying which writing-mode will be used

<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">

<fo:layout-master-set><fo:simple-page-master margin="2cm" page-width="21.0cm" page-height="29.7cm" master-name="A4-portrait"><fo:region-body margin="2cm" writing-mode="lr-tb" /> </fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence master-reference="A4-portrait"><fo:flow flow-name="xsl-region-body">

<fo:block-container>

<fo:block border-start-style="solid" border-start-width="3mm">

Hello, Tom!</fo:block>


Hello, Dick!</fo:block>




Hello, Harry!</fo:block>


Hello, Mick!</fo:block>























• Below, each block is given a border at the start of the text



















• Below, each block is given a border at the start of the text

• In normal Western documents, these borders will be at the left side<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
















In Western documents start borders are at the left-hand side

But in Semitic documents start borders should be at the right-hand side

Why before/start/end/after are useful

Why before/start/end/after are useful• We can specify style in a language-

independent way






















independent way and then add writing-mode






















independent way and then add writing-mode





















Static versus flow content• The definition of fo:page-sequence in the unofficial DTD is

<!ELEMENT fo:page-sequence

( fo:title?, fo:static-content*, fo:flow ) >• The fo:title is intended for use in interactive user agents, so is not

useful at present• The fo:flow defines content which is often longer than would fit on

one page, so it flows along a sequence of pages• An fo:page-sequence can have several fo:static-content children• fo:static-content elements are used to define content that appears

in the same place on each page• usually static content is placed in regions other than the region-body • for example, static content is often used to define headers and

footers for pages

Consider this two-page document• Each page has three

regions– region-body– region-before (silver)– region-start (grey/gray)

• The region-body contains flowing content

• The region-start is empty• But the region-before has

content– this content is the same

on all pages– it is static content

Larger view

Specifying static content<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"><fo:layout-master-set>

<fo:simple-page-master margin="2cm" page-width="21.0cm" page-height="29.7cm" master-name="A4-portrait">


<fo:region-before extent="2cm" background-color="silver"/>

<fo:region-start extent="2cm" background-color="gray"/>

</fo:simple-page-master></fo:layout-master-set>


<fo:static-content flow-name="xsl-region-before">

<fo:block font-size="30pt">Greetings</fo:block>

</fo:static-content>

<fo:flow flow-name="xsl-region-body"> <fo:block>Hello, Tom!</fo:block>

<fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>

<fo:block>Hello, Mick!</fo:block> .... <fo:block>Hello, Mick!</fo:block>

</fo:flow>

</fo:page-sequence>

</fo:root>

Location-dependent static content: page numbering<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"><fo:layout-master-set>




<fo:region-after extent="2cm" background-color="silver"/>

<fo:region-start extent="2cm" background-color="gray"/></fo:simple-page-master></fo:layout-master-set>





<fo:static-content flow-name="xsl-region-after">

<fo:block font-size="25pt">Page <fo:page-number/></fo:block>

</fo:static-content> <fo:flow flow-name="xsl-region-body">

<fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block>

<fo:block>Hello, Mick!</fo:block><fo:block>Hello, Mick!</fo:block> .... <fo:block>Hello, Mick!</fo:block>

</fo:flow>

</fo:page-sequence>

</fo:root>

Location-dependent static content: page numbering

Page numbering• The page-sequence element has several attributes for page numbering

• In the unofficial DTD, this element's attributes are <!ATTLIST fo:page-sequence

id CDATA #IMPLIED

master-name CDATA #REQUIRED

initial-page-number CDATA #IMPLIED

force-page-count

( auto | even | odd | end-on-even | end-on-odd | no-force | inherit) #IMPLIED

format CDATA #IMPLIED

letter-value ( auto | alphabetic | traditional ) #IMPLIED

grouping-separator CDATA #IMPLIED

grouping-size CDATA #IMPLIED

%inheritable-properties; >

• The attributes coloured red above control the values of the page numbers in the sequence

• The attributes coloured blue above control the appearance of the page numbers,– by controlling how these numbers are converted into strings

Specifying initial-page number<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"><fo:layout-master-set>








<fo:page-sequence master-reference="A4-portrait" initial-page-number="999" > <fo:static-content flow-name="xsl-region-before">








<fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>

<fo:block>Hello, Mick!</fo:block> .... <fo:block>Hello, Mick!</fo:block>

</fo:flow>

</fo:page-sequence>

</fo:root>

Specifying initial-page number (contd.)<fo:page-sequence master-reference="A4-portrait" initial-page-number="999">

Specifying initial-page number (contd.)• In the example just shown, we set the initial-page-number to a

specified number <fo:page-sequence master-reference="A4-portrait" initial-page-number="999">

• However, initial-page-number can also have one of these symbolic values

auto | auto-odd | auto-even • The meaning of these depends on whether or not the current page-

sequence is the first page-sequence in the document• They will not be considered at this stage

Specifying the format for page numbers• format="1" specifies that page numbers should be expressed in decimal

notation and should use the minimum possible number of digits

• Example

<fo:page-sequence master-reference="A4-portrait"

initial-page-number="9" format="1" >

Specifying the format for page numbers• format="1" specifies that page numbers should be expressed in decimal

notation and should use the minimum possible number of digits

• Example



Specifying the format for page numbers (contd.)• format="0...1" specifies that page numbers should be expressed in decimal

notation and should use at least the number of digits given

• Example



Specifying the format for page numbers (contd.)• format="0...1" specifies that page numbers should be expressed in decimal

notation and should use at least the number of digits given

• Example



Specifying the format for page numbers (contd.)• format="i" specifies that page numbers should be expressed in lower-case

Roman numerals

• Example


initial-page-number="9" format="i" >

Specifying the format for page numbers (contd.)• format="i" specifies that page numbers should be expressed in lower-case

Roman numerals

• Example


initial-page-number="9" format="i" >

Specifying the format for page numbers (contd.)• format="I" specifies that page numbers should be expressed in upper-case

Roman numerals

• Example


initial-page-number="9" format="I" >

Specifying the format for page numbers (contd.)• format="I" specifies that page numbers should be expressed in upper-case

Roman numerals

• Example



Specifying the format for page numbers (contd.)• Roman numerals can, of course, be used for large numbers

• Example



Specifying the format for page numbers (contd.)• Roman numerals can, of course, be used for large numbers

• Example



Specifying the format for page numbers (contd.)• format="a" specifies that page numbers should be expressed in lower-case

Latin letters

• Example


initial-page-number="9" format="a" >

Specifying the format for page numbers (contd.)• format="a" specifies that page numbers should be expressed in lower-case

Latin letters

• Example


initial-page-number="9" format="a" >

Specifying the format for page numbers (contd.)• format="A" specifies that page numbers should be expressed as upper-case

Latin letters

• Example


initial-page-number="9" format="A" >

Specifying the format for page numbers (contd.)• format="A" specifies that page numbers should be expressed as upper-case

Latin letters

• Example



Specifying the format for page numbers (contd.)• Although it is rarely done, Latin letters can be used for large numbers

• Example



Specifying the format for page numbers (contd.)• Although it is rarely done, Latin letters can be used for large numbers

• Example



Specifying the format for page numbers (contd.)

• The are three other number formatting attributes that we have not examined yet: letter-value ( auto | alphabetic | traditional ) #IMPLIED

grouping-separator CDATA #IMPLIED

grouping-size CDATA #IMPLIED

• The meaning of these three attributes is not yet implemented by Apache FOP

• So we will not consider them at this stage

Forcing page count• The force-page-count attribute of a page-sequence element is used to

impose a constraint on the number of pages in a page-sequence • If this constraint is not satisfied, an additional page will be added to the

end of the sequence – This page becomes the "last" page of the sequence

• The values that this attribute can have are

• even - force an even number of pages in this page-sequence • odd - force an odd number of pages in this page-sequence• end-on-even - force the last page in this page-sequence to be an even page• end-on-odd - force the last page in this page-sequence to be an even page• no-force - do not force either an even or odd number of pages• auto - the meaning of this depends on whether or not the current page-sequence is

the last page-sequence in the document; it will not be considered at this stage

Forcing page count, Example 1

• This document really needs only two pages

• But it has three pages, ...• Because we forced the page count

to be odd<fo:page-sequence

master-reference="A4-portrait"

force-page-count="odd" >

Forcing page count, Example 2

• This document really needs only two pages

• But it has three pages, ... • Because we forced the page count

to end on an even numberforce-page-count="end-on-even"

• Since there are only two pages of content, we would still have needed only two pages

• But we had specified that the first page number should be 100

<fo:page-sequence

master-reference="A4-portrait"

initial-page-number="100"

force-page-count="end-on-even" >

Accessing the current page number• The element <fo:page-number> produces an inline-area whose

content is the page-number for the page on which the inline-area is placed

Accessing the current page number• The element <fo:page-number> produces some inline text

representing the page-number of the page on which the inline text is located

<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"><fo:layout-master-set>








<fo:page-sequence master-reference="A4-portrait" initial-page-number="999" >

<fo:static-content flow-name="xsl-region-before"><fo:block font-size="30pt">Greetings</fo:block></fo:static-content>

<fo:static-content flow-name="xsl-region-after"><fo:block font-size="25pt">Page <fo:page-number/></fo:block></fo:static-content>


<fo:block>Hello, Tom! This is page <fo:page-number> </fo:block>

<fo:block>Hello, Dick! This is page <fo:page-number> </fo:block>

<fo:block>Hello, Harry! This is page <fo:page-number> </fo:block>

<fo:block>Hello, Mick! This is page <fo:page-number> </fo:block>


....


</fo:flow>

</fo:page-sequence>

</fo:root>

Accessing the current page number (contd.)

Accessing the current page number (contd.)• The text produced by the <fo:page-number> element depends on

the page numbering format that is being used


• The text produced by the <fo:page-number> element depends on the page numbering format that is being used










initial-page-number="999" format="I" > <fo:static-content flow-name="xsl-region-before"><fo:block font-size="30pt">Greetings</fo:block></fo:static-content>



<fo:block>Hello, Tom! This is page <fo:page-number> </fo:block>

<fo:block>Hello, Dick! This is page <fo:page-number> </fo:block>

<fo:block>Hello, Harry! This is page <fo:page-number> </fo:block>



....


</fo:flow>

</fo:page-sequence></fo:root>


Cross-referencing pages

Cross-referencing pages• The last line of this document refers to the page containing the

first line

Cross-referencing pages• The last line of this document refers to the page containing the

first line

Cross-referencing pages (contd.)

• The XSL-FO source-code for the document is shown below• It will be explained on the next slide



<fo:region-body margin="3cm"/><fo:region-before extent="2cm" background-color="silver"/><fo:region-after extent="2cm" background-color="silver"/><fo:region-start extent="2cm" background-color="gray"/>







<fo:block id="tomGreeting" >Hello, Tom!</fo:block> <fo:block>Hello, Dick! </fo:block><fo:block>Hello, Harry! </fo:block><fo:block>Hello, Mick! </fo:block>

<fo:block>Hello, Mick! </fo:block>

....


<fo:block>Hello, Thomas! Are you related to Tom?

(See page <fo:page-number-citation ref-id="tomGreeting"/> ) </fo:block> </fo:flow>

</fo:page-sequence>

</fo:root>

Cross-referencing pages (contd.)

• The important part of the source code is<fo:block id="tomGreeting"> Hello, Tom! </fo:block>

...

See page <fo:page-number-citation ref-id="tomGreeting"/>

• The fo:page-number-citation element generates the cross-reference

• This element can be contrasted with the fo:page-number element as follows

• The fo:page-number element produces some inline text representing the number of the page on which the element itself is located

(more precisely, the page containing the text generated by the element itself)

• The fo:page-number-citation element produces some inline text representing the number of the page which contains some other element

(more precisely, the page containing the text generated by the other element)

• The other element is the element whose id attribute has a value equal to the value of the ref-id attribute of the fo:page-number-citation element

Using cross-referencing in the page footer (contd.)• In the following document, each page has a footer of the form

Page number1 of number2

• The second number is generated by a cross-reference to the page containing the last text in the document

Using cross-referencing in the page footer (contd.)• In the following document, each page has a footer of the form

Page number1 of number2

• The second number is generated by a cross-reference to the page containing the last text in the document

Using cross-referencing in the page footer (contd.)

• The source-code for the document is shown below



<fo:region-body margin="3cm"/><fo:region-before extent="2cm" background-color="silver"/><fo:region-after extent="2cm" background-color="silver"/><fo:region-start extent="2cm" background-color="gray"/>






<fo:block font-size="25pt">

Page <fo:page-number/> of <fo:page-number-citation ref-id="endOfText"/>

</fo:block>

</fo:static-content> <fo:flow flow-name="xsl-region-body">


<fo:block>Hello, Dick! </fo:block><fo:block>Hello, Harry! </fo:block><fo:block>Hello, Mick! </fo:block>


....

<fo:block id="endOfText">Hello, Mick!</fo:block></fo:flow>

</fo:page-sequence>

</fo:root>

Multiple page masters

Multiple page masters• Until now, each document had only one simple-page-master

• This is because all our pages were intended to have the same layout

• However, frequently, we need to have different page layouts in a single document

• For example, if we are formatting a booklet which will be stapled, ...

• ... we will need to leave space for the stapling

• Left-hand pages will need a bigger margin on the right-hand side

• Right-hand pages will need a bigger margin on the left-hand-side

Multiple page masters• Until now, each document had only one simple-page-master

• This is because all our pages were intended to have the same layout

• However, frequently, we need to have different page layouts in a single document

• For example, if we are formatting a booklet which will be stapled, ...

• ... we will need to leave space for the stapling

• Left-hand pages will need a bigger margin on the right-hand side

• Right-hand pages will need a bigger margin on the left-hand-side

Multiple page masters (contd.)• The layout-master-set must contain a simple-page-master for each

type of page payout that we need• We will also need to specify when each of these simple page

masters should be used• This is done using a new type of element called a

page-sequence-master

• Elements of this type are declared in the layout-master-set• Remember that its definition in the unofficial DTD was

<!ELEMENT fo:layout-master-set

( fo:page-sequence-master*, fo:simple-page-master,

( fo:simple-page-master | fo:page-sequence-master )* ) >

• So our layout-master-set will look something like this<fo:layout-master-set>

<fo:simple-page-master ...> ... </fo:simple-page-master>

<fo:simple-page-master ...> ... </fo:simple-page-master>

<fo:page-sequence-master ...> ... </fo:page-sequence-master>


Multiple page masters: the leftPage<fo:layout-master-set>

<fo:simple-page-master master-name="leftPage"


margin-left="1.0cm" margin-right="4.5cm"

margin-top="1.0cm" margin-bottom="1.0cm">

<fo:region-before extent="1cm"/>

<fo:region-after extent="1cm"/>

<fo:region-body margin-top="1.5cm" margin-bottom="1.5cm" background-color="silver"/>


<fo:simple-page-master master-name="rightPage"






<fo:region-body margin-top="1.5cm" margin-bottom="1.5cm" />


<fo:page-sequence-master master-reference="..."> ... </fo:page-sequence-master>


Multiple page masters: the rightPage<fo:layout-master-set>

















<fo:page-sequence-master master-reference="contents"> ... </fo:page-sequence-master>


Multiple page masters: the page-sequence-master<fo:layout-master-set>

















<fo:page-sequence-master master-name="contents"> ... </fo:page-sequence-master>


fo:page-sequence-master• Its definition in the unofficial DTD is

<!ELEMENT fo:page-sequence-master

( ( fo:single-page-master-reference |

fo:repeatable-page-master-reference |

fo:repeatable-page-master-alternatives )+ ) >

<!ATTLIST fo:page-sequence-master master-name CDATA #REQUIRED > • The different types of child element for a page-sequence-master serve

different purposes• We need to specify when to use members of a set of alternative simple

page masters• So we need to use the child element called

fo:repeatable-page-master-alternatives

fo:repeatable-page-master-alternatives• The definition of this element in the unofficial DTD is

<!ELEMENT fo:repeatable-page-master-alternatives ( fo:conditional-page-master-reference+ ) >

<!ATTLIST fo:repeatable-page-master-alternatives maximum-repeats CDATA #IMPLIED >

• We see that it can contain multiple children elements of typefo:conditional-page-master-reference

• Each of these specifies when to use a particular page master

fo:conditional-page-master-reference• The definition of this element in the unofficial DTD is slightly wrong• It should be

<!ELEMENT fo:conditional-page-master-reference EMPTY>

<!ATTLIST fo:conditional-page-master-reference master-reference CDATA #REQUIRED page-position ( first | last | rest | any | inherit ) #IMPLIED odd-or-even ( odd | even | any | inherit ) #IMPLIED blank-or-not-blank ( blank | not-blank | any | inherit ) #IMPLIED >

• This element specifies when a particular page master (identified by the master-reference attribute) should be used

• The other attributes describe the conditions that must be satisfied when the particular page master is used

Example page-sequence-master• Suppose we want the first page to be a rightPage• This means we want odd-numbered pages to use the rightPage master• And even-numbered pages to use the leftPage master

Example page-sequence-master• Suppose we want the first page to be a rightPage• This means we want odd-numbered pages to use the rightPage master• And even-numbered pages to use the leftPage master

<fo:page-sequence-master master-name="booklet">

<fo:repeatable-page-master-alternatives>

<fo:conditional-page-master-reference

master-reference="leftPage"

odd-or-even="even" />

<fo:conditional-page-master-reference

master-reference="rightPage"

odd-or-even="odd" />

</fo:repeatable-page-master-alternatives>

</fo:page-sequence-master>

The page-sequence • Make the page-sequence refer to the booklet page-sequence-master

<fo:page-sequence master-reference="booklet" initial-page-number="1" format="1" >








<fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block>

<fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>

<fo:block>Hello, Mick!</fo:block> ... <fo:block>Hello, Mick!</fo:block>

</fo:flow>

</fo:page-sequence>

The result• See that Page 1 is a rightPage and Page 2 is a leftPage

Including images

Including images• One way of including an image in a document is to use the

fo:external-graphic element

• Its definition in the unofficial DTD is<!ELEMENT fo:external-graphic EMPTY >

<!ATTLIST fo:external-graphic

%graphic-properties; src CDATA #IMPLIED >

• The graphic properties are:<!ENTITY % graphic-properties "

id CDATA #IMPLIED content-type CDATA #IMPLIED

%accessibility-properties;

%relative-position-properties;

%aural-properties;

%border-padding-background-properties;

%margin-properties-inline;

%area-alignment-properties-inline;

%box-size-properties;

%font-properties;

%line-height-properties;

%keeps-and-breaks-properties-atomic;

content-height CDATA #IMPLIED

content-width CDATA #IMPLIED

scaling ( uniform | non-uniform | inherit ) #IMPLIED

scaling-method ( auto | integer-pixels | resample-any-method | inherit ) #IMPLIED

overflow ( visible | hidden | scroll | auto | error-if-overflow | inherit ) #IMPLIED ">

Including images (contd.)• Example usage

<fo:block text-align="end">

<fo:external-graphic src=“URL-or-path/to/some/image-file“/>

content-width="99px" content-height="109px" />

</fo:block>

Graphic inclusion, example 1<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">

<fo:layout-master-set> <fo:simple-page-master master-name="ordinaryPage"page-width="21.0cm" page-height="29.7cm“ margin-left="1.0cm" margin-right="2.0cm"margin-top="1.0cm" margin-bottom="2.0cm">

<fo:region-body margin-top="1.5cm" margin-bottom="1.5cm“ background-color="silver" /> <fo:region-before extent="1cm"/><fo:region-after

extent="1cm"/></fo:simple-page-master></fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" ><fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Greetings</fo:block>

</fo:static-content><fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page

<fo:page-number/></fo:block></fo:static-content><fo:flow flow-name="xsl-region-body">

<fo:block><fo:external-graphic src="man.gif" content-height="150pt" /></fo:block><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>… <fo:block>Hello, Mick!</fo:block></fo:flow></fo:page-sequence>

</fo:root>

Graphic inclusion, example 1 (contd.)

• Image in default position, at start/left side of block



<fo:region-body margin-top="1.5cm" margin-bottom="1.5cm“ background-color="silver" /> <fo:region-before extent="1cm"/><fo:region-after

extent="1cm"/></fo:simple-page-master></fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" ><fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Greetings</fo:block>

</fo:static-content><fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page

<fo:page-number/></fo:block></fo:static-content><fo:flow flow-name="xsl-region-body">

<fo:block text-align="end”><fo:external-graphic src="man.gif" content-height="150pt" /></fo:block><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>… <fo:block>Hello, Mick!</fo:block></fo:flow></fo:page-sequence>

</fo:root>


• Image aligned to end/right side of block

Images: floating• The definition of XSL-FO includes various

elements and attributes which are designed for floating parts of a document

• Unfortunately, these are not implemented in Apache FOP at present

• So, if you really want to wrap text around an image you must emulate floating by using tables or by using negative space-before



<fo:region-body margin-top="1.5cm" margin-bottom="1.5cm“ background-color="silver" /> <fo:region-before extent="1cm"/><fo:region-after extent="1cm"/></fo:simple-page-master></fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" ><fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Greetings</fo:block> </fo:static-content><fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page <fo:page-number/></fo:block></fo:static-content><fo:flow flow-name="xsl-region-body">

<fo:block text-align="end”><fo:external-graphic src="man.gif" content-height=“75pt" /></fo:block><fo:block space-before=“-75pt" margin-right="80pt">This is a sentence. This is another sentence. This is another sentence. And this is another sentence. … And this is another sentence.</fo:block><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>… <fo:block>Hello, Mick!</fo:block></fo:flow></fo:page-sequence>

</fo:root>


• Negative space-before used to make text blocks “wrap” around image

Hotlinks

Hotlinks• Hotlinks can be created by using the fo:basic-link element• Its specification in the unofficial DTD is

<!ELEMENT fo:basic-link ( %mixed-level; )* > <!ATTLIST fo:basic-link %inline-properties; external-destination CDATA #IMPLIED internal-destination CDATA #IMPLIED indicate-destination ( true | false ) #IMPLIED show-destination ( replace | new ) #IMPLIED destination-placement-offset CDATA #IMPLIED target-processing-context CDATA #IMPLIED target-presentation-context CDATA #IMPLIED target-stylesheet CDATA #IMPLIED >

• Either the external-destination and internal-destination should be specified.– If both are specified, the system may either report an error or

use the internal-destination property

Hotlinks, example 1<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"><fo:layout-master-set> <fo:simple-page-master master-name="ordinaryPage"page-width="21.0cm" page-height="29.7cm“ margin-left="1.0cm" margin-

right="2.0cm"margin-top="1.0cm" margin-bottom="2.0cm"> <fo:region-body margin-top="1.5cm" margin-bottom="1.5cm“ background-color="silver" /> <fo:region-before extent="1cm"/><fo:region-after extent="1cm"/></fo:simple-page-master></fo:layout-master-set><fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" ><fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Greetings</fo:block> </fo:static-content><fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page <fo:page-number/></fo:block></fo:static-content><fo:flow flow-name="xsl-region-body">

<fo:block><fo:basic-link internal-destination="endOfText">Click-here-to-go-to-the-end-of-the-text</fo:basic-link><fo:basic-link external-destination=“url('http://www.ucc.ie')">Click-here-to-go-to-the-UCC-website</fo:basic-link></fo:block><fo:block text-align="end”><fo:external-graphic src="man.gif" content-height=“75pt" /></fo:block><fo:block space-before=“-75pt" margin-right="80pt">This is a sentence. This is another sentence. This is another sentence. And this is another sentence. … And this is

another sentence.</fo:block> <fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>…

<fo:block id=“endOfText”>Hello, Mick!</fo:block></fo:flow></fo:page-sequence>

</fo:root>

Hotlinks example 1 (contd.)• Notice how the areas generated by the fo:basic-link elements

- are inline areas and - have no decoration

Hotlinks, example 2 – highlighting links

Hotlinks, example 2 – highlighting links<?xml version="1.0" encoding="UTF-8"?><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"><fo:layout-master-set> <fo:simple-page-master master-name="ordinaryPage"page-width="21.0cm" page-height="29.7cm“ margin-left="1.0cm" margin-

right="2.0cm"margin-top="1.0cm" margin-bottom="2.0cm"> <fo:region-body margin-top="1.5cm" margin-bottom="1.5cm“ background-color="silver" /> <fo:region-before extent="1cm"/><fo:region-after extent="1cm"/></fo:simple-page-master></fo:layout-master-set><fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" ><fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Greetings</fo:block> </fo:static-content><fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page <fo:page-number/></fo:block></fo:static-content><fo:flow flow-name="xsl-region-body">

<fo:block><fo:basic-link color="blue" text-decoration="underline" internal-destination="endOfText">Click here to go to the end of the text</fo:basic-link><fo:basic-link color="blue" text-decoration="underline" external-destination=“url('http://www.ucc.ie')">Click here to go to the UCC website</fo:basic-link></fo:block><fo:block text-align="end”><fo:external-graphic src="man.gif" content-height=“75pt" /></fo:block><fo:block space-before=“-75pt" margin-right="80pt">This is a sentence. This is another sentence. This is another sentence. And this is another sentence. … And this is

another sentence.</fo:block> <fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block><fo:block>Hello, Tom!</fo:block><fo:block>Hello, Dick!</fo:block><fo:block>Hello, Harry!</fo:block><fo:block>Hello, Mick!</fo:block>…

<fo:block id=“endOfText”>Hello, Mick!</fo:block></fo:flow></fo:page-sequence>

</fo:root>

Hotlinks example 2 (contd.)• The appearance of links below is like the default in HTML• However, we can specify a completely different appearance if we

wish

Tables

HTML versus FO tables• HTML tables have this hierarchy

<table>

<caption>

<colgroup>

<col>

<thead>

<tr>

<th>

<tbody>

<tr>

<td>

<tfoot>

<tr>

<td>

• XSL-FO tables have this hierarchy <fo:table-and-caption>

<fo:table-caption>

<fo:table>

<fo:table-column>

<fo:table-header>

<fo:table-row>

<fo:table-cell>

<fo:table-body>

<fo:table-row>

<fo:table-cell>

<fo:table-footer>

<fo:table-row>

<fo:table-cell>

Example table<fo:table table-layout="fixed" border-width="1px" border-style="solid">

<fo:table-column column-width="3cm"/>



<fo:table-header text-align="center" background-color="red">

<fo:table-row>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block font-weight="bold">City</fo:block></fo:table-cell>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block font-weight="bold">Location</fo:block></fo:table-cell>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block font-weight="bold">Population</fo:block></fo:table-cell>

</fo:table-row>

</fo:table-header>

<fo:table-body background-color="blue">

<fo:table-row>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block>Dublin</fo:block></fo:table-cell>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block>East coast</fo:block></fo:table-cell>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block>1,200,00</fo:block></fo:table-cell>

</fo:table-row>

<fo:table-row>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block>Cork</fo:block></fo:table-cell>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block>South coast</fo:block></fo:table-cell>

<fo:table-cell padding="1mm" border-width="1px" border-style="solid"><fo:block>200,000</fo:block></fo:table-cell>

</fo:table-row>

</fo:table-body>

</fo:table>

The result

Table properties<!ENTITY % table-properties "

border-collapse ( collapse | separate | inherit ) #IMPLIED

border-spacing CDATA #IMPLIED

border-separation CDATA #IMPLIED

border-separation.inline-progression-dimension CDATA #IMPLIED

border-separation.block-progression-dimension CDATA #IMPLIED

caption-side

( before | after | start | end | top | bottom | left | right | inherit ) #IMPLIED

empty-cells ( show | hide | inherit ) #IMPLIED

table-layout ( auto | fixed | inherit ) #IMPLIED

table-omit-header-at-break ( true | false | inherit ) #IMPLIED

table-omit-footer-at-break ( true | false | inherit ) #IMPLIED

">

Lists

Lists• We create lists using the fo:list-block element• Its specification in the unofficial DTD

<!ELEMENT fo:list-block ( fo:list-item+ ) > <!ATTLIST fo:list-block %block-properties;>

• The specification for the fo:list-item is <!ELEMENT fo:list-item ( fo:list-item-label, fo:list-item-body ) >

<!ATTLIST fo:list-item %block-properties;>

• The specification for the fo:list-item-label is

<!ELEMENT fo:list-item-label ( %blocks; )+ >

<!ATTLIST fo:list-item-label %block-properties;>

• The specification for the fo:list-item-body is

<!ELEMENT fo:list-item-body ( %blocks;)+ > <!ATTLIST fo:list-item-body %block-properties;>

List, example 1• Here is a simple list

List, example 1• Here is a simple list

<fo:list-block>

<fo:list-item>

<fo:list-item-label>

<fo:block>1</fo:block>

</fo:list-item-label>

<fo:list-item-body>

<fo:block>Hello Tom!</fo:block>

</fo:list-item-body>

</fo:list-item>

<fo:list-item>

<fo:list-item-label><fo:block>2</fo:block></fo:list-item-label>

<fo:list-item-body><fo:block>Hello Dick!</fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

List, example 1• Here is a simple list• However, it is too simple, as the next slide shows<fo:list-block>

<fo:list-item>

<fo:list-item-label>

<fo:block>1</fo:block>

</fo:list-item-label>

<fo:list-item-body>

<fo:block>Hello Tom!</fo:block>

</fo:list-item-body>

</fo:list-item>

<fo:list-item>

<fo:list-item-label><fo:block>2</fo:block></fo:list-item-label>

<fo:list-item-body><fo:block>Hello Dick!</fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

The layout is wrong

The layout is wrong

What's wrong?• There are some attributes whose values we must

consider• Before we continue with lists, we should look

again at the attributes that are defined for blocks

Block attributes (revisited)• Here, again, are the block attributes in the unofficial DTD <!ATTLIST fo:block %block-properties;> <!ENTITY % block-properties " id CDATA #IMPLIED %inheritable-properties; "> <!ENTITY % inheritable-properties " color CDATA #IMPLIED relative-align ( before | baseline | inherit ) #IMPLIED span ( none | all | inherit ) #IMPLIED %accessibility-properties; %absolute-or-relative-position-properties;

%border-padding-background-properties; %border-precedence-properties; %aural-properties; %box-size-properties;

%margin-properties-inline; %area-properties; %area-alignment-properties-inline; %character-properties; %table-properties; %list-properties; %float-properties; %line-related-properties; %leader-properties; %keeps-and-breaks-properties-block; %hyphenation-properties-block;


margin-properties-inline

<!ENTITY % margin-properties-inline "

%margin-properties-block;

space-start CDATA #IMPLIED

space-start.minimum CDATA #IMPLIED

space-start.optimum CDATA #IMPLIED

space-start.maximum CDATA #IMPLIED

space-start.precedence CDATA #IMPLIED

space-start.conditionality ( retain | discard ) #IMPLIED

space-end CDATA #IMPLIED

space-end.minimum CDATA #IMPLIED

space-end.optimum CDATA #IMPLIED

space-end.maximum CDATA #IMPLIED

space-end.precedence CDATA #IMPLIED

space-end.conditionality ( retain | discard ) #IMPLIED ">

margin-properties-block

<!ENTITY % margin-properties-block "


space-after CDATA #IMPLIED

space-after.minimum CDATA #IMPLIED

space-after.optimum CDATA #IMPLIED

space-after.maximum CDATA #IMPLIED

space-after.precedence CDATA #IMPLIED

space-after.conditionality ( retain | discard ) #IMPLIED

space-before CDATA #IMPLIED

space-before.minimum CDATA #IMPLIED

space-before.optimum CDATA #IMPLIED

space-before.maximum CDATA #IMPLIED

space-before.precedence CDATA #IMPLIED

space-before.conditionality ( retain | discard ) #IMPLIED

start-indent CDATA #IMPLIED

end-indent CDATA #IMPLIED ">

start-indent and end-indent

• The start-indent attribute of a block-area specifies

the distance from

the start-edge of the content-rectangle of the containing reference-area

to

the start-edge of the content-rectangle of the block-area

• The end-indent attribute of a block-area specifies

the distance from

the end-edge of the content-rectangle of the containing reference-area

to

the end-edge of the content-rectangle of the block-area

start-indent, example<?xml version="1.0" encoding="UTF-8"?>


<fo:layout-master-set>...</fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage"






<fo:block font-size="20pt">Page <fo:page-number/>

</fo:block>



<fo:block>

This is an example sentence.

</fo:block>

<fo:block start-indent="1cm">

This is another example sentence.

</fo:block></fo:flow>

</fo:page-sequence>

</fo:root>

end-indent, example<?xml version="1.0" encoding="UTF-8"?>


<fo:layout-master-set>...</fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage"



<fo:block font-size="20pt">Greetings</fo:block></fo:static-content>


<fo:block font-size="20pt">Page <fo:page-number/>

</fo:block></fo:static-content>


<fo:block>

This is an example paragraph....This is an example paragraph.

</fo:block>

<fo:block background-color="red"

start-indent="1cm"

end-indent="1cm">

This is yet another example paragraph. ...This is yet another example paragraph.

</fo:block></fo:flow></fo:page-sequence></fo:root>

Indents for for list item labels and bodies• The labels and bodies of list item can have

indents• This gives us four attributes for controlling layout

Example, to motivate producing "definition lists"

• Suppose we want to render some of its content as an XSL-FO list which looks like a HTML definition list


• Consider this XML document• Suppose we want to render some of its content as an XSL-FO list which

looks like a HTML definition list




<towns>

<town>

<name>Dublin</name>

<location>East coast of Ireland</location>

<population>1,200,000</population>

</town>

<town>

<name>Cork</name>

<location>South coast of Ireland</location>

<population>200,000</population>

</town>

</towns>




<towns>

<town>

<name>Dublin</name>

<location>East coast of Ireland</location>

<population>1,200,000</population>

</town>

<town>

<name>Cork</name>

<location>South coast of Ireland</location>

<population>200,000</population>

</town>

</towns>

Example, using FO lists to produce "definition lists"<fo:flow flow-name="xsl-region-body">

<fo:block>Dublin</fo:block>

<fo:list-block>

<fo:list-item>

<fo:list-item-label><fo:block> location: </fo:block></fo:list-item-label>

<fo:list-item-body><fo:block> East coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>

<fo:list-item-label><fo:block> population: </fo:block> </fo:list-item-label>

<fo:list-item-body><fo:block> 1,200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

<fo:block>Cork</fo:block>

<fo:list-block>

<fo:list-item>

<fo:list-item-label"><fo:block> location: </fo:block></fo:list-item-label>

<fo:list-item-body"><fo:block> South coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>

<fo:list-item-label><fo:block> population: </fo:block></fo:list-item-label>

<fo:list-item-body><fo:block> 200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

</fo:flow>

Poor layout

Poor layout

"Definition" lists example (contd.)

• Let's add some background-color, to help see where we are



<fo:list-block start-indent="1cm" end-indent="1cm" background-color="red" > <fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>





</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>

</fo:flow>


• Let's add some background-color, to help see where we are






</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>





</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>

</fo:flow>

The red areas are the list-blocks


• We can avoid the overlap by giving a start-indent to the bodies



<fo:list-block start-indent="1cm" end-indent="1cm" background-color="red" >

<fo:list-item>


<fo:list-item-body start-indent="4cm"> <fo:block> East coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>


<fo:list-item-body start-indent="4cm"><fo:block> 1,200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>



<fo:list-item>


<fo:list-item-body start-indent="4cm"> <fo:block> South coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>


<fo:list-item-body start-indent="4cm"> <fo:block> 200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

</fo:flow>


• We can avoid the overlap by giving a start-indent to the bodies




<fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>



<fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>

</fo:flow>

A bit better, but not good enough

• Before

• After


• To avoid overlap, the bodies need a bigger start-indent




<fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>



<fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>

</fo:flow>


• To avoid overlap, the bodies need a bigger start-indent




<fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>



<fo:list-item>



</fo:list-item>

<fo:list-item>



</fo:list-item>

</fo:list-block>

</fo:flow>

No overlap, but perhaps the separation is too large?

Controlling layout of list items

• As we have seen, we can control the layout of list items by specifying the required indents for the labels and bodies of these items

• But this can require a lot of experimentation, especially with "definition" lists

• XSL-FO provides two functions to reduce the work• These are

– label-end(), used to compute the end-indent for labels– body-start(), used to compute the start-indent for bodies

• Let's try using body-start


• Using body-start to set the start-indent for the list item bodies




<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> East coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> 1,200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>



<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> South coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> 200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

</fo:flow>

Better than nothing, but not good enough

• We need to use something else as well

Block attributes (revisited)• Here, again, are the block attributes in the unofficial DTD <!ATTLIST fo:block %block-properties;> <!ENTITY % block-properties " id CDATA #IMPLIED %inheritable-properties; "> <!ENTITY % inheritable-properties " color CDATA #IMPLIED relative-align ( before | baseline | inherit ) #IMPLIED span ( none | all | inherit ) #IMPLIED %accessibility-properties; %absolute-or-relative-position-properties;

%border-padding-background-properties; %border-precedence-properties; %aural-properties; %box-size-properties; %margin-properties-inline; %area-properties; %area-alignment-properties-inline; %character-properties; %table-properties;

%list-properties; %float-properties; %line-related-properties; %leader-properties; %keeps-and-breaks-properties-block; %hyphenation-properties-block;


list-properties

• Here are the list-property attributes in the unofficial DTD <!ENTITY % list-properties "

provisional-distance-between-starts CDATA #IMPLIED

provisional-label-separation CDATA #IMPLIED ">

• The values of these attributes are used by label-end() and body-start()• The initial value of provisional-label-separation is 6.0pt• The initial value of provisional-distance-between-starts is 24.0pt

Computing label-end() and body-start()

• label-end() =

width of the content-rectangle of the reference-area into which the list-block is placed

- (the value of the provisional-distance-between-starts

+ the value of the start-indent

+ start-intrusion-adjustment

- the value of the provisional-label-separation)

of the closest ancestor fo:list-block

• body-start() = the value of the start-indent

+ start-intrusion-adjustment

+ the value of the provisional-distance-between-starts

of the closest ancestor fo:list-block


• Setting provisional-distance-between-starts



<fo:list-block start-indent="1cm" end-indent="1cm" background-color="red" provisional-distance-between-starts="3cm" > <fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> East coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> 1,200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>


<fo:list-block start-indent="1cm" end-indent="1cm" background-color="red" provisional-distance-between-starts="3cm">

<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> South coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>


<fo:list-item-body start-indent="body-start()"> <fo:block> 200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

</fo:flow>

The result

This works, but …• The body-start() function worked but we still had to specify a value

for provisional-distance-between-starts• The main advantage is that we did not need to specify this value in

each of the list item bodies– We need to specify it only once for each list-block

• But we still had to decide what the value should be and this required some experimentation, in order to find a distance which was long enough to prevent overlap with the longest label

• It would be better if we could automatically compute the required distance

• We can, indeed, automate the computation• But it must be done in XSLT, at the time the XSL-FO document is

being generated

A digression, back to XSLT

Computing required provisional-distance-between-starts for FO list blocks

• We need to compute a distance which will prevent overlap with the longest list-item-label

• Since list-item-labels are derived from the tag names in the source XML document, we need to compute the length of the longest tag name


• Consider this XML document• Suppose we want to automatically compute the length of the longest

tag name for the child elements of the <town> elements• The XSLT stylesheet on the next slide will do it<towns> <town> <name>Dublin</name> <location>East coast of Ireland</location> <population>1,200,000</population> </town> <town> <name>Cork</name> <location>South coast of Ireland</location> <population>200,000</population> </town></towns>










XSL stylesheet to compute longest tagname<?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format">


<xsl:template match="/"> <fo:root>  <xsl:apply-templates select="./towns/town[position()=1]“ /> </fo:root></xsl:template>

 <xsl:template match="town"><xsl:for-each select="./*"><xsl:sort select="string-length(name())" order="descending"/><xsl:if test="position()=1">maxLabelLength=<xsl:value-of select="string-length(name())"/></xsl:if></xsl:for-each></xsl:template>

</xsl:stylesheet>

Unfortunately, …

• Unfortunately, there is a problem• Apache FOP seems to have a bug in it• The stylesheet shown on the previous slide is correct• We can see this if we execute the stylesheet with

another XSLT processor, the Saxon processorhttp://saxon.sourceforge.net/

• But Apache FOP does not execute it correctly• We will see this on the next few slides

http://saxon.sourceforge.net/

Executing the stylesheet with Apache FOP

• Assume the XML document is in a file called towns.xml• Assume the XSLT stylesheet is in a file called towns.xsl• Use Apache FOP to place the output in a file called towns.fo

fop -xml towns.xml -xsl towns.xsl -foout towns.fo

• The resultant content in towns.fo is<?xml version="1.0" encoding="UTF-8"?>

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">maxLabelLength=8</fo:root>

• But this is wrong

• The longest tagname is population, which is 10 characters long

• However, there is nothing wrong with the stylesheet, as we can see if we execute it with the Saxon processor

• The result is shown on the next slide

Executing the stylesheet with Saxon

• Again, assume the XML document is in a file called towns.xml• Again, assume the XSLT stylesheet is in a file called towns.xsl• Use Saxon to place the output in a file called towns.fo

java -jar /usr/local/saxon/saxon9he.jar towns.xml towns.xsl > towns.fo

• The resultant content in towns.fo is<?xml version="1.0" encoding="UTF-8"?>

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">maxLabelLength=10</fo:root>

• This is correct

• The longest tagname is population, which is 10 characters long

Using both Saxon and FOP• Since there is an error in FOP, we could use Saxon and FOP

together• We could Saxon to generate an XSL-FO file from an XML file and

an XSLT filejava -jar /usr/local/saxon/saxon9he.jar towns.xml towns.xsl > towns.fo

• We could then use Apache FOP to generate a PDF file from the XSL-FO file which was created by Saxonfop -fo towns.fo -pdf towns.pdf

Back to generating XSL-FO lists

A stylesheet which calculates the max label length

• The next two slides provide an XSLT stylesheet which calculates the number of characters in the longest tagname

• It then specifies that number of em units as the provisional distance between starts

• The stylesheet uses three templates– One template generates the top-level structure of the XSL-FO

document and calls a template which generates the XSL-FO output for each individual town

– The template which generates the XSL-FO output for an individual town uses a third template to determine the provisional distance between starts which should be used in the list block for the town

– The third template examines the does not consider the <name> child when trying to determine the length of the longest child tag

– Note that the second and third templates both match <town> elements, but are distinguished from each other by having different mode attritbutes

































Stylesheet, page 1<?xml version="1.0"?><xsl:stylesheet version="1.0“ xmlns:xsl=http://www.w3.org/1999/XSL/Transform xmlns:fo="http://www.w3.org/1999/XSL/Format">




<fo:layout-master-set> <fo:simple-page-master master-name="ordinaryPage“ page-width="21.0cm" page-height="29.7cm" margin-left="4.5cm" margin-right="1.0cm“ margin-top="1.0cm" margin-bottom="1.0cm"> <fo:region-body margin-top="1.5cm" margin-bottom="1.5cm background-color="silver" /> <fo:region-before extent="1cm"/> <fo:region-after extent="1cm"/> </fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" > <fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Towns</fo:block></fo:static-content> <fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page

<fo:page-number/></fo:block></fo:static-content> <fo:flow flow-name="xsl-region-body"> <!– process each town using the template for outputFO mode --> <xsl:apply-templates select="./towns/town" mode="outputFO“ /> </fo:flow> </fo:page-sequence>

</fo:root>

</xsl:template>

http://www.w3.org/1999/XSL/Transform

Stylesheet, page 2<xsl:template match="town" mode="outputFO" > <fo:block><xsl:value-of select="name"/></fo:block> <fo:list-block> <xsl:attribute name="provisional-distance-between-starts"> <xsl:apply-templates select="." mode="getMaxLabel" />em </xsl:attribute> <xsl:for-each select="./*[not(name()='name')]"> <fo:list-item> <fo:list-item-label> <fo:block> <xsl:value-of select="name()"/>: </fo:block> </fo:list-item-label> <fo:list-item-body start-indent="body-start()"> <fo:block> <xsl:value-of select="."/> </fo:block> </fo:list-item-body> </fo:list-item> </xsl:for-each> </fo:list-block></xsl:template>

<xsl:template match="town" mode="getMaxLabel" > <xsl:for-each select="./*[not(name()='name')]"> <xsl:sort select="string-length(name())" order="descending"/> <xsl:if test="position()=1"><xsl:value-of select="string-length(name())"/></xsl:if> </xsl:for-each></xsl:template>

</xsl:stylesheet>

The resultant output• Use Saxon to get the XSL-FO output• Use fop to process the XSL-FO into PDF• The result is shown below• The separation is too long because we are using em units and this

produces a length greater than that actually rendered for proportional fonts, in which different letters have different widths– Some people have introduced extensions to XSLT processors like Saxon

in order to better estimate the actual rendered length of text– See, for example,

http://www.innodata-isogen.com/knowledge_center/tools_downloads/saxon_extensions

Another stylesheet which calculates max label length

• The next two slides provide a different XSLT stylesheet which calculates the number of characters in the longest tagname

• It differs from the previous one in that it assumes that all towns have the same set of child elements– so the length of the longest child tagname need be calculated only once, for

the first town

• The stylesheet uses three templates• One template generates the top-level structure of the XSL-FO document • This calls another template which examines the first town, to get the

length of the longest child tagname• Then it calls yet another template which generates the XSL-FO output

for each individual town• This stylesheet actually generates exactly the same XSL-FO as the

previous one• The only difference is that it calculates the length of the provisional

distance between starts just once, puts this value in a variable and passes it as a parameter to the template which processes individual towns

Another stylesheet which calculates max label length<?xml version="1.0"?><xsl:stylesheet version="1.0“ xmlns:xsl=http://www.w3.org/1999/XSL/Transform xmlns:fo="http://www.w3.org/1999/XSL/Format">


<xsl:template match="/"><fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> <fo:layout-master-set> <fo:simple-page-master master-name="ordinaryPage“ page-width="21.0cm" page-height="29.7cm" margin-left="4.5cm" margin-right="1.0cm“ margin-top="1.0cm" margin-bottom="1.0cm"> <fo:region-body margin-top="1.5cm" margin-bottom="1.5cm background-color="silver" /> <fo:region-before extent="1cm"/> <fo:region-after extent="1cm"/> </fo:simple-page-master> </fo:layout-master-set>

<fo:page-sequence master-reference="ordinaryPage“ initial-page-number="1" format="1" > <fo:static-content flow-name="xsl-region-before"><fo:block font-size="20pt">Towns</fo:block></fo:static-content> <fo:static-content flow-name="xsl-region-after"><fo:block font-size="20pt">Page

<fo:page-number/></fo:block></fo:static-content> <fo:flow flow-name="xsl-region-body">

<xsl:variable name="provisional-distance">



<xsl:apply-templates select="./towns/town[position()=1]" mode="getMaxLabel"/>em</xsl:variable>

<xsl:apply-templates select="./towns/town" mode="outputFO">

<xsl:with-param name="provisional" select="$provisional-distance" />

</xsl:apply-templates> </fo:flow> </fo:page-sequence></fo:root></xsl:template>

http://www.w3.org/1999/XSL/Transform

Another stylesheet which calculates max label length<xsl:template match="town" mode="outputFO" > <xsl:param name="provisional-distance"/> <fo:block><xsl:value-of select="name"/></fo:block> <fo:list-block> <xsl:attribute name="provisional-distance-between-starts"> <xsl:value-of select="$provisional-distance"/> </xsl:attribute> <xsl:for-each select="./*[not(name()='name')]"> <fo:list-item> <fo:list-item-label> <fo:block> <xsl:value-of select="name()"/>: </fo:block> </fo:list-item-label> <fo:list-item-body start-indent="body-start()"> <fo:block> <xsl:value-of select="."/> </fo:block> </fo:list-item-body> </fo:list-item> </xsl:for-each> </fo:list-block></xsl:template>

<xsl:template match="town" mode="getMaxLabel" > <xsl:for-each select="./*[not(name()='name')]"> <xsl:sort select="string-length(name())" order="descending"/> <xsl:if test="position()=1"><xsl:value-of select="string-length(name())"/></xsl:if> </xsl:for-each></xsl:template>

</xsl:stylesheet>

Bulleted lists

"Bulleted" lists example

• Just using body-start; no usage of provisional-distance-between-starts



<fo:list-block start-indent="1cm" end-indent="1cm" background-color="red">

<fo:list-item>

<fo:list-item-label><fo:block> • </fo:block></fo:list-item-label>

<fo:list-item-body start-indent=" body-start() "> <fo:block>Location: East coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>

<fo:list-item-label><fo:block> • </fo:block> </fo:list-item-label>

<fo:list-item-body start-indent=" body-start() "> <fo:block>Population: 1,200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>


<fo:list-block start-indent="1cm" end-indent="1cm" background-color="red">

<fo:list-item>

<fo:list-item-label"><fo:block> • </fo:block></fo:list-item-label>

<fo:list-item-body start-indent=" body-start() "> <fo:block>Location: South coast of Ireland </fo:block></fo:list-item-body>

</fo:list-item>

<fo:list-item>

<fo:list-item-label><fo:block> • </fo:block></fo:list-item-label>

<fo:list-item-body start-indent=" body-start() "> <fo:block>Population: 200,000 </fo:block></fo:list-item-body>

</fo:list-item>

</fo:list-block>

</fo:flow>

The result

A useful website

• Seehttp://www.stylusstudio.com/w3c/xslfo/

Documents

XSL Formatting Objects