@xpath() Function

@xpath() function is used to query an XML string or a pre-parsed Node object.

(since v5.0)

Syntax:

@xpath(xml-input, xpath-expression [,encoding])
 

xml-input

It can either be a plain XML string or pre-parsed Node object to query.

xpath-expression

The XPath expression that queries the XML Input. Note that the XPath query should return a string result NOT a NodeList.

encoding

Default 'UTF-8'

Examples:

@parsexml('<root><item><PRICE>1200</PRICE></item></root>',v:NODE)  

@xpath(v:NODE, '//PRICE')  @// result: 1200

@xpath(<root><item><PRICE curr="USD">1200</PRICE></item></root>, '//PRICE/@curr')  @// result: USD

Prefix usage in an XPath expression:

v:XML

 
<root>

  <cns:customer id="1" xmlns:cns="http://www.localhost.com/customer">        

    <ons:order xmlns:ons="http://www.localhost.com/order">

      <date>01-01-2011</date>

      <product>

        <name>Notebook</name>

        <price>1000</price>

        <quantity>1</quantity>

      </product>

      <product>

        <name>Notebook</name>

        <price>1000</price>

        <quantity>1</quantity>

      </product>

    </ons:order>

  </cns:customer>

  <cns2:customer id="2" xmlns:cns2="http://www.localhost.com/customer2">        

    <ons:order xmlns:ons="http://www.localhost.com/order">

      <date>01-01-2011</date>

      <product>

        <name>Desktop Computer</name>

        <price>750</price>

        <quantity>2</quantity>

      </product>

    </ons:order>

  </cns2:customer>

</root>

@parsexml(v:XML, v:NODE)

@xpath(v:NODE, '/root/cns2:customer[@id = 2]/ons:order/product/name') @// result: Desktop Computer

@xpath(v:NODE, '/root/cns2:customer/ons:order/product/name') @// result: Notebook  

An XPath expression without namespace prefix can also be used for the above example. To make it happen, @parsexml() function should be used as follows or an XML string should be used as the input. For the both of the cases the namespace prefixes will be ignored and the value of the first node that matches will be returned.

@set(v:XML,'<root><cns:customer id="1" ... </cns2:customer></root>')

@parsexml(v:XML, v:NODE,, false)

@xpath(v:NODE, '/root/customer[@id = 2]/order/product/name') @// result: Desktop Computer

or

@xpath(v:XML, '/root/customer[@id = 2]/order/product/name') @// result: Desktop Computer

Default Namespace Usage:

v:XML

 
<root>

  <cns:customer id="1" xmlns:cns="http://www.localhost.com/customer">        

    <order xmlns="http://www.localhost.com/order">

      <date>01-01-2011</date>

      <product>

        <name>Notebook</name>

        <price>1000</price>

        <quantity>1</quantity>

      </product>

      <product>

        <name>Notebook</name>

        <price>1000</price>

        <quantity>1</quantity>

      </product>

    </order>

  </cns:customer>

  <cns2:customer id="2" xmlns:cns2="http://www.localhost.com/customer2">        

    <order xmlns="http://www.localhost.com/order">

      <date>01-01-2011</date>

      <product>

        <name>Desktop Computer</name>

        <price>750</price>

        <quantity>2</quantity>

      </product>

    </order>

  </cns2:customer>

</root>

@parsexml(v:XML, v:NODE)

@xpath(v:NODE, '/root/cns2:customer[@id = 2]/:order/:product/:name') @// result: Desktop Computer

If a namespace is defined on a node and there is no namespace prefix used for it (the default namespace) ":" should be used as the prefix as in the case above.

See @parsexml()