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Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
XSLT and XHTML Demos for XML.Gov
Ken Sall Consulting
Ken Sall, Principal
September 18, 2002
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Goals
To illustrate how using XHTML and XSLT on XML.Gov can facilitate different views of data (or documents).
To briefly compare/contrast several approaches to XSLT use:– server-side and client-side
– browser-specific and cross-browser.
Part of XML.Gov vision: to use XML on site.
"The Medium is the Message"
Demo Home Page: http://kensall.com/gov
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Non-Goals
Flash and Wow factor.
Demonstrate a wide variety of XSLT capabilities.
Code review.
Instead, we'll focus on inputs/outputs and sorting/displaying capabilities, relatively simple ways to increase value of XML.Gov as more and more documents are posted and data is captured.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
HTML to Valid XHTML 1.0 Convert HTML to XHTML using HTML Tidy.
Use W3C HTML Validation Service to identify errors (e.g., tag overlap, missing quotes, deprecated elements and attributes not in XHTML 1.0, etc.).
Fix errors. May take some time but once fixed, maintenance is easy.
Brand with W3C "Valid XHTML 1.0" logo.
Simply click logo after editing to re-validate.Valid XHTML Demo
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Sorting Government XML Efforts
Begin with HTML version.
Convert to structured XHTML (e.g., using HTML Tidy).
Use XSLT to extract inner table and sort.– By organization
– By name of effort
Added Benefit: Clean up inconsistencies in pathnames (absolute vs. relative) which can be detected and adjusted using XSLT.
Efforts Sort Demo
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Government XML Efforts: XHTML
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Sorting Government XML Efforts
XHTML "mined" to extract tabular data. Links generated from XML using XSLT.
XHTML "mined" to extract tabular data. Links generated from XML using XSLT.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
XML WG Participants Sort
Defined DTD describing Working Group participant. Strictly strawman.
Only Name and Organization are required. Other optional elements include: Title, URL, ExtraURL, SpecialInterests, and ContactInfo.
Sort by Name and Organization.
Server-side and client-side transformations.
WG Participants Sort Demo
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
DTD for XML WG Participants <!ELEMENT Participants (Participant+)>
<!ATTLIST Participants
meetingDate CDATA #IMPLIED meetingName CDATA #IMPLIED
meetingLocation CDATA #IMPLIED >
<!ELEMENT Participant (Name, Title?, Organization, URL?, ExtraURL?, SpecialInterests?, ContactInfo?)>
<!ATTLIST Participant workingGroupMember (yes | no) "yes" >
<!ELEMENT Name (First, Initial?, Last)>
<!ELEMENT Title (#PCDATA)> <!-- participant's title, if known -->
<!ELEMENT First (#PCDATA)> <!ELEMENT Initial (#PCDATA)>
<!ELEMENT Last (#PCDATA)>
<!ELEMENT Organization (#PCDATA)>
<!ATTLIST Organization detail CDATA #IMPLIED
type (gov | com | edu | mil | other) "gov" >
<!ELEMENT URL (#PCDATA)> <!-- URL of organization -->
<!ELEMENT ExtraURL (#PCDATA)>
<!ELEMENT SpecialInterests (Interest+)> <!-- ETC -->
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
XML WG Participants Sort
Different sorts may extract different numbers of columns, as well as different ordering.
Different sorts may extract different numbers of columns, as well as different ordering.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Server-side vs. Client-side
Server-side: XSLT transformations executed on the Web server, either in realtime or at pre-defined time. Browser is sent (X)HTML.– Pro: Works in all browsers since XSLT is server-side.– Con: If done in realtime, heavy server load for popular sites.
Client-side: Browser is sent XML which references an XSLT stylesheet. The XSLT transformation is executed by the browser in realtime.– Pro: Lightens server load.– Potential Pro: Multiple sorts (in-place DOM manipulation) without additional
server requests.– Con: Built-in XSLT processor required. Only works in IE 5.5+ and NS 6+. DOM
manipulation requires latest browsers.
UPDATEDUPDATED
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Client-Side Sorting: xml.house.gov
Very impressive in IE 6.
Looks nice in Moz 1.0 and NS 7 but sort doesn't work due to Microsoft-specific hooks.
Doesn't work at all in NS 6.2.3.
Doesn’t work in Moz 1.1? [TBD]
Very impressive in IE 6.
Looks nice in Moz 1.0 and NS 7 but sort doesn't work due to Microsoft-specific hooks.
Doesn't work at all in NS 6.2.3.
Doesn’t work in Moz 1.1? [TBD]
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Client-Side: Browser DetectionAccessibility: If browser detection is added, different pages can be served as needed. IE users can experience the in-place sort; NS users can view an alternative.
Accessibility: If browser detection is added, different pages can be served as needed. IE users can experience the in-place sort; NS users can view an alternative.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Client-Side Sorting: IE Only
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Client-Side Sorting: JavaScript
By Manos BatsisBy Manos Batsis
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Client-Side: Cross-Browser XML API
API that models Microsoft's XMLDocument and XSLDocument so that in-place sorting will work with Netscape 6 & 7 and Mozilla 1.x, as well as in IE.
DOMDocument implementation; emulates IE extensions (i.e., "xml" property, transformNode(), transformNodeToObject(), etc.) in NS/Moz.
Implemented entirely in JavaScript; requires detailed knowledge of IE and NS browser internals.
Developers simply use the JavaScript API.
Under development (XMLHTTP); snapshot demo.
By Manos BatsisBy Manos BatsisUPDATEDUPDATED
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Cross-Browser XML API
ADDEDADDED
By Manos BatsisBy Manos Batsis
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Multi-Page Sorting of Brainstorming Ideas
Start with Owen Ambur's HTML table as input.
Convert to XHTML.
Create a simple XML vocabulary (with DTD) to better describe the tabular data.
Convert the XHTML to custom XML using XSLT.
Use one XSLT stylesheet per sort criterion to sort XML data in several ways, displaying the results as HTML. [Next step: re-use]
Brainstorming Sort Demo
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Brainstorming: Original HTML
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Brainstorming: XML Data Rep.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Brainstorming: In XML Spy
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Sorting of Brainstorming Ideas
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Sorting of Brainstorming Ideas Client: 4.23 sec.
Server: 1.43 sec.
Client: 4.23 sec.
Server: 1.43 sec.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Recommendations for XML.Gov1. Convert key pages to XHTML to facilitate
future transformations (data extraction). Brand with W3C Valid XHTML 1.0 logo. Re-validate after editing.
2. Consider using HTML editors that support XHTML, Tidy, and validation (e.g., Macromedia HomeSite, XML Spy, etc.).
3. If data is specialized and/or reusable, write a DTD or XML Schema to describe data, mainly to clarify what information is required, optional, constrained to a certain data type, etc.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
Recommendations for XML.Gov [cont.]
4. Handle browser differences a) Detect browser vendor/version (JavaScript)
b) Provide alternatives (client-side, server-side, alternate pages)
c) Accessibility always matters.
5. Use XSLT for server-side and eventually client-side processing.
Copyright © 2002. Kenneth B. Sall. All Rights Reserved.
301-725-2859www.KenSall.com
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