Best way to check xml link?

Question

I have many links in my xml files, for example:

<name id="key1"></name> 
<ref to="key1"></ref>

so the best way to check ref / @ to is defined in the name / @ id.

Xsd? DTD? or programming using XPATH?

Answer 1

The XML-schema : , , , - see. The this example. ID IDREF IDREFS xs:key

In XPath : a function. id()

In XSLT : and . <xsl:key> key()

Answer 2

Xml IDREF. . , xml, xml . XSLT/XPath.