How to select the first element with a specific attribute using XPath

ripper234_11236 0
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The XPath bookstore/book[1] selects the first book node under bookstore.

How can I select the first node that matches a more complicated condition, e.g. the first node that matches /bookstore/book[@location='US']

xpath
9 Answers

Use:

(/bookstore/book[@location='US'])[1]

This will first get the book elements with the location attribute equal to 'US'. Then it will select the first node from that set. Note the use of parentheses, which are required by some implementations.

Note, this is not the same as /bookstore/book[1][@location='US'] unless the first element also happens to have that location attribute.

user_671680

As an explanation to Jonathan Fingland's answer:

  • multiple conditions in the same predicate ([position()=1 and @location='US']) must be true as a whole
  • multiple conditions in consecutive predicates ([position()=1][@location='US']) must be true one after another
  • this implies that [position()=1][@location='US'] != [@location='US'][position()=1]
    while [position()=1 and @location='US'] == [@location='US' and position()=1]
  • hint: a lone [position()=1] can be abbreviated to [1]

You can build complex expressions in predicates with the Boolean operators "and" and "or", and with the Boolean XPath functions not(), true() and false(). Plus you can wrap sub-expressions in parentheses.

Tomalak_187710

if namespace is provided on the given xml, its better to use this.

(/*[local-name() ='bookstore']/*[local-name()='book'][@location='US'])[1]
user_64290720
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