NOTE: These slides have not been updated since 2003. They have been superseded by the book An Introduction to XML and Web Technologies Addison-Wesley, and the accompanying online material. Please see http://www.brics.dk/ixwt/ for more information. Anders Møller and Michael Schwartzbach, February 2006

THE XML REVOLUTION  -  TECHNOLOGIES FOR THE FUTURE WEB

Constructing complex types

• attribute declarations:
  • <attribute name="..." type=".." use=".."/>
    where type refers to a simple type definition and use is either optional (the default), required, or prohibited (used with type derivations)

  • <anyAttribute ... />

• one of the following content model kinds:
  • empty content (the default)

  • simple content: <simpleContent> ... </simpleContent> (only character data is allowed)

  • regexp content: a (restricted) combination of
    • <sequence> ... </sequence>
    • <choice> ... </choice>
    • <all> ... </all>

    containing element references of the form

    • <element ref="..." minOccurs=".." maxOccurs=".."/>
      where ref refers to an element definition, and minOccurs and maxOccurs constrain the number of occurences (default: 1)
    • <any .../>

    (if complexType has the attribute mixed="true", arbitrary character data is also allowed)

Example:

<complexType name="order_type" mixed="true"> <choice> <element ref="n:address"/> <sequence> <element ref="n:email" minOccurs="0" maxOccurs="unbounded"/> <element ref="n:phone"/> </sequence> </choice> <attribute name="id" type="unsignedInt" use="required"/> </complexType>

• grouping of definitions:
  • attribute groups: groups of attribute declarations can be defined with <attributeGroup name="..."> ... </...> and used with <attributeGroup use="..."/>.

  • element groups: similarly, groups of regexp content model descriptions can be defined and used with the group construct.

• anyType is a built-in type that allows anything

• within a complexType, the content model must appear before all attribute declarations

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