XML/XPath: Difference between revisions

<lang AutoHotkey>

FileRead, inventory, xmlfile.xml

MsgBox % names

</lang>

<lang AutoHotkey>

#Include xpath.ahk

MsgBox % xpath(doc, "/inventory/section/item/name")

</lang>

<lang csharp> XmlReader XReader;

// Either read the xml from a string ...

XReader = XmlReader.Create(new StringReader("<inventory title=... </inventory>"));

// ... or read it from the file system.

XReader = XmlReader.Create("xmlfile.xml");

// Create a XPathDocument object (which implements the IXPathNavigable interface)

// which is optimized for XPath operation. (very fast).

IXPathNavigable XDocument = new XPathDocument(XReader);

// Create a Navigator to navigate through the document.

XPathNavigator Nav = XDocument.CreateNavigator();

Nav = Nav.SelectSingleNode("//item");

// Move to the first element of the selection. (if available).

if(Nav.MoveToFirst())

{

Console.WriteLine(Nav.OuterXml); // The outer xml of the first item element.

}

// Get an iterator to loop over multiple selected nodes.

XPathNodeIterator Iterator = XDocument.CreateNavigator().Select("//price");

while (Iterator.MoveNext())

{

Console.WriteLine(Iterator.Current.Value);

}

Iterator = XDocument.CreateNavigator().Select("//name");

// Use a generic list.

List<string> NodesValues = new List<string>();

while (Iterator.MoveNext())

{

NodesValues.Add(Iterator.Current.Value);

}

// Convert the generic list to an array and output the count of items.

Console.WriteLine(NodesValues.ToArray().Length);</lang>

<lang C++>#include <vector>

}

</lang>

<cfsavecontent variable="xmlString">

<inventory

...

</inventory>

</cfsavecontent>

<cfset xml = xmlParse(xmlString)>

&lt;!--- First Task --->

<cfset itemSearch = xmlSearch(xml, "//item")>

&lt;!--- item = the first Item (xml element object) --->

<cfset item = itemSearch[1]>

&lt;!--- Second Task --->

<cfset priceSearch = xmlSearch(xml, "//price")>

&lt;!--- loop and print each price --->

<cfloop from="1" to="#arrayLen(priceSearch)#" index="i">

#priceSearch[i].xmlText#&lt;br/>

</cfloop>

&lt;!--- Third Task --->

&lt;!--- array of all the name elements --->

<cfset names = xmlSearch(xml, "//name")>

&lt;!--- visualize the results --->

<cfdump var="#variables#">

<lang d>

import kxml.xml;

}

</lang>

<lang javascript> //create XMLDocument object from file

var xhr = new XMLHttpRequest();

xhr.open('GET', 'file.xml', false);

xhr.send(null);

var doc = xhr.responseXML;

//get first <item> element

var firstItem = doc.evaluate( '//item[1]', doc, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null ).singleNodeValue;

alert( firstItem.textContent );

//output contents of <price> elements

var prices = doc.evaluate( '//price', doc, null, XPathResult.ANY_TYPE, null );

for( var price = prices.iterateNext(); price != null; price = prices.iterateNext() ) {

alert( price.textContent );

}

//add <name> elements to array

var names = doc.evaluate( '//name', doc, null, XPathResult.ANY_TYPE, null);

var namesArray = [];

for( var name = names.iterateNext(); name != null; name = names.iterateNext() ) {

namesArray.push( name );

}

alert( namesArray );</lang>

<lang javascript> //create XML object from file

var xhr = new XMLHttpRequest();

xhr.open('GET', 'file.xml', false);

xhr.send(null);

var doc = new XML(xhr.responseText);

//get first <item> element

var firstItem = doc..item[0];

alert( firstItem );

//output contents of <price> elements

for each( var price in doc..price ) {

alert( price );

}

//add <name> elements to array

var names = [];

for each( var name in doc..name ) {

names.push( name );

}

alert( names );</lang>

<lang perl> use XML::XPath qw();

my $x = XML::XPath->new('<inventory ... </inventory>');

[$x->findnodes('//item[1]')->get_nodelist]->[0];

print $x->findnodes_as_string('//price');

$x->findnodes('//name')->get_nodelist;</lang>

<lang php>

<?php

//PHP5 only example due to changes in XML extensions between version 4 and 5 (Tested on PHP5.2.0)

$doc = DOMDocument::loadXML('<inventory title="OmniCorp Store #45x10^3">...</inventory>');

//Load from file instead with $doc = DOMDocument::load('filename');

$xpath = new DOMXPath($doc);

/*

1st Task: Retrieve the first "item" element

*/

$nodelist = $xpath->query('//item');

$result = $nodelist->item(0);

/*

2nd task: Perform an action on each "price" element (print it out)

*/

$nodelist = $xpath->query('//price');

for($i = 0; $i < $nodelist->length; $i++)

{

//print each price element in the DOMNodeList instance, $nodelist, as text/xml followed by a newline

print $doc->saveXML($nodelist->item($i))."\n";

}

/*

3rd Task: Get an array of all the "name" elements

*/

$nodelist = $xpath->query('//name');

//our array to hold all the name elements, though in practice you'd probably not need to do this and simply use the DOMNodeList

$result = array();

//a different way of iterating through the DOMNodeList

foreach($nodelist as $node)

{

$result[] = $node;

}

</lang>

<lang python>

# Python has basic xml parsing built in

namesArray = xmldoc.getElementsByTagName("name")

</lang>

<lang R>

## Require the XML package you can download from http://www.omegahat.org/RSXML/

(namesArray <- sapply(getNodeSet(doc, "//name"), xmlValue))

</lang>

<lang ruby> #Example taken from the REXML tutorial (http://www.germane-software.com/software/rexml/docs/tutorial.html)

require "rexml/document"

include REXML

#create the REXML Document from the string (%q is Ruby's multiline string, everything between the two @-characters is the string)

doc = Document.new(

%q@<inventory title="OmniCorp Store #45x10^3">

...

</inventory>

@

)

# The invisibility cream is the first <item>

invisibility = XPath.first( doc, "//item" )

# Prints out all of the prices

XPath.each( doc, "//price") { |element| puts element.text }

# Gets an array of all of the "name" elements in the document.

names = XPath.match( doc, "//name" )</lang>

<lang scala>

scala> val xml = <inventory title="OmniCorp Store #45x10^3">

values: Array[String] = Array(Invisibility Cream, Levitation Salve, Blork and Freen Instameal, Grob winglets)

</lang>

Dim first_item = xml.XPathSelectElement("//item")

Console.WriteLine(first_item)

For Each price In xml.XPathSelectElements("//price")

Console.WriteLine(price.Value)

Next

Dim names = (From item In xml.XPathSelectElements("//name") Select item.Value).ToArray

<lang xquery>

(:

</result>

</lang>

<lang>

<?xml version="1.0" encoding="UTF-8"?>

</result>

</lang>

<pre><nowiki>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

</xsl:stylesheet>

</nowiki></pre>