Can relaxng specify an unordered set of elements with the same name, but different attributes?

Question

Im working to automate the testing of an API which takes and returns XML, so I want to translate the documented return data of the API into schema as much as possible. I cho

Answer 1

See if the following schema helps

<grammar xmlns="http://relaxng.org/ns/structure/1.0">
<start>
    <element name="item">
        <interleave>
            <element name="id"><text/>
            </element>
            <element name="name"><text/></element>
            <oneOrMore>
                <ref name="link"/>
            </oneOrMore>
        </interleave>
    </element>
</start>

<define name="link">
    <element name="link">
        <attribute name="href"/>
        <choice>
            <group>
                <attribute name="rel"><value>self</value></attribute>
                <attribute name="type"><value>type1</value></attribute>
            </group>
            <group>
                <attribute name="rel"><value>download</value></attribute>
                <attribute name="type"><value>type2</value></attribute>
            </group>
            <group>
                <attribute name="rel"><value>relatedData</value></attribute>
                <attribute name="type"><value>type3</value></attribute>
            </group>
        </choice>
    </element>
</define>
</grammar>

Answer 2

It looks like you have stumbled upon a restriction on interleave in RELAX NG. I would try to do this in Schematron, or perhaps a combination of RELAX NG and Schematron.

Here is a snippet that checks your <link> elements using the version of Schematron that is supported by Jing:

<schema xmlns="http://www.ascc.net/xml/schematron">
  <pattern name="link pattern">
    <rule context="item">
      <assert test='count(link) = 3'>There must be 3 link elements.</assert>
      <assert test="count(link[@rel = 'self' and @type ='type1']) = 1">There must be 1 link element wwhere @rel='self' and @type='type1'.</assert>
      <assert test="count(link[@rel = 'download' and @type ='type2']) = 1">There must be 1 link element where @rel='download' and @type='type2'.</assert>
      <assert test="count(link[@rel = 'relatedData' and @type = 'type3']) = 1">There must be 1 link element where @rel='relatedData' and @type='type3'.</assert>
    </rule>
  </pattern>
</schema>