How to check IDREFS length in xPath

问题

I have the next DTD definition

    <!ELEMENT testNode EMPTY>
    <!ATTLIST testNode
          listOfNodes IDREFS #REQUIRED
          bestNode IDREF #REQUIRED
    >

when I get /testNode/@listOfNodes I have to check if there are more then one ref in listOfNodes. How can I do this ?

回答1:

If you have multiple IDREF vlues in attribute listOfNodes, it must be separated by space as per DTD rules. So, you may follow this example to check multiple values:

let $x := <testNode listOfNodes="d1 d2"/>
return
  if(contains($x/@listOfNodes, ' '))
  then "Yes"
  else "No"

For multiple value it will return "Yes" otherwise "No"

来源：https://stackoverflow.com/questions/16980015/how-to-check-idrefs-length-in-xpath