Simplexml is giving me the wrong results - php

Question

I have a simple xml below:
<?xml version="1.0" encoding="utf-8"?>
<catalogue>
<category name="textbook" id="100" parent="books">
<product id="20000">
<author>Gambardella, Matthew</author>
<title>XML Developer's Guide</title>
<genre>Computer</genre>
<price>44.95</price>
<publish_date>2000-10-01</publish_date>
<description>An in-depth look at creating applications
with XML.</description>
</product>
<product id="20001">
<author>Gambardellas, Matthew</author>
<title>XML Developer's Guide</title>
<genre>Computer</genre>
<price>44.95</price>
<publish_date>2000-10-01</publish_date>
<description>An in-depth look at creating applications
with XML.</description>
</product>
</category>
<category name="fiction" id="101" parent="books">
<product id="2001">
<author>Ralls, Kim</author>
<title>Midnight Rain</title>
<genre>Fantasy</genre>
<type>Fiction</type>
<price>5.95</price>
<publish_date>2000-12-16</publish_date>
<description>A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen
of the world.</description>
</product>
</category>
</catalogue>
I am using php simplexml library to parse it as follows: (note there are two category nodes. The first category contains two 'product' children. My aim is to get an array that contains those two children of first 'category'
$xml = simplexml_load_file($xml_file) or die ("unable to load XML File!".$xml_file);
//for each product, print out info
$cat = array();
foreach($xml->category as $category)
{
if($category['id'] == 100)
{
$cat = $category;
break;
}
}
$prod_arr = $category->product;
Here is the problem. I am expecting an array with two products children but its only returning one product. What am I doing wrong or is this a php bug? Please help!

Answer 1

You can use SimpleXMLElement::xpath() to get all product elements that are children of a specific category element. E.g.
// $catalogue is your $xml
$products = $catalogue->xpath('category[#id="100"]/product');
foreach($products as $p) {
echo $p['id'], ' ', $p->title, "\n";
}
prints
20000 XML Developer's Guide
20001 XML Developer's Guide

Answer 2

For start, your XML file is not well defined. You should probably start and end it with <categories> tag.
Replace the last assignment with the following:
$prod_array = array();
foreach ($cat->product as $p) {
$prod_array[] = $p;
}

Answer 3

$cat = array();
foreach ($xml->category as $category)
{
$attributes = $category->attributes();
if(isset($attributes['id']) && $attributes['id'] == 100)
{
$cat = $category;
break;
}
}