xpath expression from xml with namespace prefix

Question

I could not get the following xpath expression to work when the xml path namespace prefix set.

/bk:BookStore/bk:Books/bk:Book[text()='Time Machine']

XML is:

<BookStore xmlns:bk="http://www.bookstore.com/book#">
  <bk:Books>
    <bk:Book id="1">Time Machine></bk:Book>
  </bk:Books>
</bk:BookStore>

You need to pass the prefix/namespace-URI binding to your XPath engine. Why? Because prefixes are not important for name test, but namespace URI are. So a:node could select b:node as long as a and b prefixes are binding to the same namespace URI. — user357812
– user357812, Commented Oct 14, 2010 at 12:46

Ivivi Vavava · Accepted Answer · 2011-11-18 13:31:52Z

42

Or even better (and more portable), without the unnecessary prefix:

/*/*[local-name()='Books'] ... and so on

The function local-name ignores any prefix, which, as correctly stated by commenters, can vary.

edited Nov 18, 2011 at 13:31

answered Nov 18, 2011 at 11:14

Ivivi Vavava

7731 gold badge8 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Arne Over a year ago

Why did someone downvote this? I found this an excellent solution to avoid dealing with namespaces, which are just annoying and unnecessary 99% of the time.

joachim Over a year ago

If the namespaces are just a hurdle you have to get past, imposed on you externally -- as they often are -- then this is definitely the way to go.

javanna · Accepted Answer · 2012-07-24 12:44:50Z

21

Without more information about the host language (in which you attempt to evaluate XPath expressions) it is not possible to provide an useful recommendation.

Generally, one needs to "register" a namespace with a namespace manager and this also associates a prefix to the registered namespace. Then, using this NamespaceManager object as an argument to the XPath-evaluation method, one can specify as argument to this method an XPath expression that contains names prefixed by that particular prefix.

Workarounds:

/*/*[name()='bk:Books']/*[name()='bk:Book' and text()='Time Machine']

edited Jul 24, 2012 at 12:44

javanna

60.4k14 gold badges147 silver badges125 bronze badges

answered Oct 14, 2010 at 18:01

Dimitre Novatchev

244k27 gold badges307 silver badges438 bronze badges

4 Comments

Ashwin Over a year ago

I am using xml signature in java. I wan to select the elements to be signed using xpath in the trasnforms section. How do I give the xpath expression when I have prefixes and namespaces in my xml document.

Dimitre Novatchev Over a year ago

@Ashwin: This answer shows exactly how to do this (one of the possible ways), without registering namespaces. The second possible way is to register the namespace to prefix bindings in which element names referenced in the XPath expression are -- then the XPath expression can contain prefixes and be more readable. This second way requires to use for the namespace registering implementation-provided APIs and one needs to read the appropriate documentation.

David L. Over a year ago

More proper 'workaround' is something like: //*[fn:namespace-uri()="http://www.bookstore.com/book#" and local-name()='Book']. Actually, it is not even a workaround, just a verbose xpath. For brevity there are the prefixes and the environment that you use to execute xpath should provide you with a way of specifying them (the prefixes used in the xpath can be different from those used in the XML file).

Dimitre Novatchev Over a year ago

@DavidL.This is a useful workaround. However, it hardcodes the namespace-uri and must always be modified, if the namespace itself is modified. Imagine having to maintain many such expressions. The advantage of using a specific namespace prefix is that in such cases only a single modification would be necessary.

Collectives™ on Stack Overflow

xpath expression from xml with namespace prefix

2 Answers 2

2 Comments

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related