How to parse/extract url from an xml file? - php

Question

I have an XML file that contains the following type of data
<definition name="/products/phone" path="/main/something.jsp" > </definition>
There are dozens of nodes in the xml file.
What I want to do is extract the url under the 'name' parameter so my end result will be:
http://www.mysite.com/products/phone.jsp
Can I do this with a so called XML parser? I have no idea where to begin. Can someone steer me to a direction. What tools do I need to achieve something like that?
I am particularly interested in doing this with PHP.

Answer 1

It should be easy to append a path to an existing URL and expected resource type given the above basic XML.
If you are comfortable with C#, and you know there is one and only one "definition" element, here is a self contained little program that does what you require (and assumes you are loading the XML from a string):
using System;
using System.Xml;
public class parseXml
{
private const string myDomain = "http://www.mysite.com/";
private const string myExtension = ".jsp";
public static void Main()
{
string xmlString = "<definition name='/products/phone' path='/main/something.jsp'> </definition>";
XmlDocument doc = new XmlDocument();
doc.LoadXml(xmlString);
string fqdn = myDomain +
doc.DocumentElement.SelectSingleNode("//definition").Attributes["name"].ToString() +
myExtension;
Console.WriteLine("Original XML: {0}\nResultant FQDN: {1}", xmlString, fqdn);
}
}
You are going to need to be careful with SelectSingleNode above; the XPath expression assumes there is only one "definition" node and that you are searching from the document root.
Fundamentally, it's worthwhile to read a primer on XML. Xml is not difficult, it's a self describing hierarchical data format - lots of nested text, angle brackets, and quotation marks :).
A good primer would probably be that at the W3 Schools:
http://www.w3schools.com/xml/xml_whatis.asp
You may also want to read up on streaming (SAX/StreamReader) vs. loading (DOM/XmlDocument) Xml:
What is the difference between SAX and DOM?
I can provide a Java example too, if you feel that would be helpful.

Answer 2

Not sure if you solved your problem, so here is a PHP solution:
$xml = <<<DATA
<?xml version="1.0"?>
<root>
<definition name="/products/phone" path="/main/something.jsp"> </definition>
<definition name="/products/cell" path="/main/something.jsp"> </definition>
<definition name="/products/mobile" path="/main/something.jsp"> </definition>
</root>
DATA;
$arr = array();
$dom = new DOMDocument('1.0', 'UTF-8');
$dom->loadHTML($xml);
$xpath = new DOMXPath($dom);
$defs = $xpath->query('//definition');
foreach($defs as $def) {
$attr = $def->getAttribute('name');
if ($attr != "") {
array_push($arr, $attr);
}
}
print_r($arr);
See IDEONE demo
Result:
Array
(
[0] => /products/phone
[1] => /products/cell
[2] => /products/mobile
)