Question

Given the following xml-snippet:

<Environment>
...
    <MySqlConfiguration>
      <ActiveServer>1@db1</ActiveServer>
      <PassiveServer>2@db1</PassiveServer>
      <Replicate from="1@db1" to="2@db1" />
      <Replicate from="2@db1" to="1@db1" />
    </MySqlConfiguration>
...
</Environment>

I want to restrict from/to values to those specified in ActiveServer or PassiveServer

in XSD, I try the following:

 <xs:element name="Environment" type="environment" >
    <xs:key name="ServerKey">
      <xs:selector xpath=".//ActiveServer|PassiveServer"/>
      <xs:field xpath="*"/>
    </xs:key>
    <xs:keyref name="ServerKeyRef" refer="ServerKey">
      <xs:selector xpath=".//Replicate"/>
      <xs:field xpath="@from"/>
    </xs:keyref>
    ...
  </xs:element>

However, the xpath="*" field selector in the key does not work (it does not get the text node of the Active/PassiveServer elements). xpath="text()" does not work either. Doing something like:

<xs:element name="Environment" type="environment" >
    <xs:key name="ServerKey">
      <xs:selector xpath="Environment"/>
      <xs:field xpath="ActiveServer|PassiveServer"/>
    </xs:key>
    <xs:keyref name="ServerKeyRef" refer="ServerKey">
      <xs:selector xpath=".//Replicate"/>
      <xs:field xpath="@from"/>
    </xs:keyref>
    ...
  </xs:element>

Does not work (field must refer to one instance; specifying just one of those would work).

Is there some way I’m overlooking on how to grab an element’s text content in a field xpath value?

Answer 1

I would expect the following to work:

  <xs:selector xpath=".//ActiveServer|.//PassiveServer"/>
  <xs:field xpath="."/>

Note “|” has lowest precedence so the “.//” needs to be repeated. The BNF from XSD Rec:

 Selector  ::=  Path ( '|' Path )*