为xpath标识符使用in-exact字符串

Question

I am finding I need to locate an almost regexp type string using an xpath query but have not been able to see how to manage it. The current query I am using is:

  $result = $xpath->query('//ul/li[starts-with(@id, "message-")]');

Which is resulting in some false positives. It should really be looking for message-123 or message-987 etc. Is there a way to tell xpath to use something similar to a \d (digit) in regexps?

Answer 1

Use this XPath 1.0 expression for 'message-' + integer pattern:

//ul/li[
   @id[
      starts-with(., 'message-') 
    and
      number(
         substring-after(., 'message-')
      ) 
    = floor(
         substring-after(., 'message-')
      )
   ] 
]