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ACG 4401
XML SchemasXML NamespacesXMLink
+The XML Foundation
Many participants – an extended family! XML Instance documents – carry data in context
Each must be parsed into its component parts XML Schemas – define the rules a class of documents
must follow Can be used to validate documents & contents
XSLT – provide processing instructions Can be used to process XML documents
Namespaces – qualify elements & attributes Differentiate & associate them with a URI
XPath … XLink … XQuery … XML Processors are not designed equally!
+ XML Schema Language
Language used to create Schema Documents
Schema Used to define the structure and content of Instance documents
Well-formatted XML document Definition: “provide a means for defining the structure, content and
semantics of XML documents.” (W3C)
Defines structure and contents of Instance Document Similar to an ER-Diagram for databases Defines Each Element and Attribute Its Structure
Includes Business Rules Cardinalities
Used to Validate Instance Document Means Instance Document conforms to Schema Rules
+XML Schema
.xsd extension But won’t open in IE so use .xml if using that browser
Defines each attribute and extension
+Vocabularies & Schemas
XBRL & UBL are vocabularies XBRL for Financial Reporting UBL for Business Documents
Vocabularies are designed using Agreed upon element names Agreed upon element types Agreed upon element sequence/structure
Defined by Schemas
6+Namespaces
Each XML Vocabulary is associated with a unique NameSpace A unique identifier (think, primary key) Universal Resource Identifier
Local Name (e.g. TeeTimeResevations.xml) URL (http://www……)
Used to prevent naming collisions (more later)
+ Vocabularies and Namespaces
Namespace
A Unique Identifier
Unique Prefix refers to URI
Points to where information in an XML Document can be found. (URI)
Attribute of Root Element
Definition: “XML namespace: In XML, a namespace is a collection of names, identified by a URI reference, that are used in XML documents as element types and attribute names. In order for XML documents to be able to use elements and attributes that have the same name but come from different sources, there must be a way to differentiate between the markup elements that come from the different sources.” (Webopeida) (Technical Information from W3.org)
Used to preclude naming collisions
Method for distinguishing between the same element name for different elements
<inv:id>10001</inv:id> ...
<employee:id>18897</employee:id>
8+Types of Elements Simple
contain only data
<SalesOrderID>98765</SalesOrderID>
Complex
contain other elements (i.e. Root & Parent)
<PartyName>
<Name>Bicycles Online, Inc.</Name></PartyName>
contain attributes
<PriceAmount currencyID="USD">730.55</PriceAmount>
+Simple Element Definition
Declare Name
Declare Type
<xs:element name=“ID” type=“xs:string”/>
Type= Defines the data type:
string Integer date decimal other types
+Complex Element (Parent)
Declares Name
Declares type
Declares Structure
11+Complex Element (Parent) xml
<xs:element name="Party">
<xs:complexType>
<xs:sequence>
<xs:element ref="PartyName" minOccurs="1" maxOccurs="1"/>
<xs:element ref="PostalAddress" minOccurs="1" maxOccurs="1"/>
<xs:element ref="Contact" minOccurs="0" maxOccurs="1"/>
</xs:sequence>
</xs:complexType>
</xs:element>
+Complex Element (attribute)
Declare Name
Declare Type
Define element and attribute(s)
13+Complex (Attribute) xml
<xs:element name="PriceAmount">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:decimal">
<xs:attribute name="currencyID" type="xs:string”use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
+Create a Schema from a non-vocabulary instance document
Identify types of elements Simple Complex – Parent Complex – Attribute
Create Prolog
Create Root element
Work down from 1st element to last
15+Root Element
Root element is used to declare namespace(s)
<xs:schema xmlns:xs=“http://www.w3.org/2001/XMLSchema”>
xs: = namespace prefix
xmlns:xs defines prefix to use for namespace
“http:www.w3.org/2001/XMLSchema” location of Namespace, where the dictionary is
Prefix is used before each tag xs:tagname
+
Creating Schema from Instance DocumentPizzaOrders
16
+UBL Schemas
Schemas for each document type
Common Basic Components Defines Simple Elements Defines Complex (attribute) Elements Prefix: cbc (Namespace prefix)
Common Aggregate Components Defines Complex (Parent) Elements Prefix: cac (Namespace prefix)
+Creating UBL Document Schemas
1. Declare NameSpaces and qualifiers
2. Import necessary Schemas
3. Define Root Element
1. Reference Reusable data components
2. Declare Cardinalities
+Declaring a Namespace (in the UBL instance document)
<Catalogue xmlns="UBLCatalogueDocument"
xmlns:cbc="UBLCommonBasicComponents"
xmlns:cac="UBLCommonAggregateComponents">
Since UBLCatalogueDocument does NOT have a prefix any element in the instance document without a prefix relates to this namespace.
UBL Catalogue Instance with namespaces
+1. UBL Namespace Declaration in Root Element
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="UBLCatalogueDocument"
xmlns="UBLCatalogueDocument"
xmlns:cbc="UBLCommonBasicComponents"
xmlns:cac="UBLCommonAggregateComponents"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
+Namespace Clarification
targetNamespace="UBLCatalogueDocument“ The schema being created/used is applied to the
UBLCatalogueDocument namespace
elementFormDefault="qualified“ Element names will use a namespace prefix
CAC: CBC:
attributeFormDefault="unqualified“ Attribute names will not use a namespace prefix
+2. UBL Import
<xs:import namespace="UBLCommonBasicComponents"
schemaLocation="http://www.buec.udel.edu/whitec/UBLCommonBasicComponents/UBLCommonBasicComponentsSchema.xsd"/>
<xs:import namespace="UBLCommonAggregateComponents"
schemaLocation="http://www.buec.udel.edu/whitec/UBLCommonAggregateComponents/UBLCommonAggregateComponentsSchema.xsd"/>
+3. UBL Root Element (Catalogue)
<xs:element name="Catalogue">
<xs:complexType>
<xs:sequence>
<xs:element ref="cbc:ID" minOccurs="1" maxOccurs="1"/>
<xs:element ref="cbc:Name" minOccurs="1" maxOccurs="1"/>
<xs:element ref="cbc:IssueDate" minOccurs="1" maxOccurs="1"/>
<xs:element ref="cac:ProviderParty" minOccurs="1" maxOccurs="1"/>
<xs:element ref="cac:ReceiverParty" minOccurs="1" maxOccurs="1"/>
<xs:element ref="cac:CatalogueLine" minOccurs=”1” maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
Put it all together: The Entire Schema
+Validating XML
Ensure that Instance Document Follows business rules Data types are correct Data is properly sequenced
+XML Linking Language
XLink Uses attributes to describe relationships between
elements Simple: HTML type links Extended: More complex Relationship links
27+Simple links
Unidirectional and always Outbound
Link to list of approved Vendor
<InventoryItem xlink:type”simple” xlink:href=“http://….”/>
28+Extended Links
Attributes: xlink:type=“extended”
Used in Parent element Xlink:type=“locator”
Remote resource In Child element
Xlink:href=“http://….” In Child Element
