用php和xpath解析xml

Question

I'm trying to parse an xml file to return a item with a specific id only, but having trouble making it work.

here's what I have in php

$xml_str = file_get_contents("test.xml");
$xml = simplexml_load_string($xml_str);
$albid = $_GET['id'];

$nodes = $xml->xpath('//library/book[@id=1]');

foreach($nodes as $node) {
echo $node['title'].'<br/>';
}

First, the php is not returning anything from the xml file.

What would I need to fix to return the data?

Also, how would I enter $albid into the xpath so that the id will be retrieved from the link?

Any pointers in the right direction would be appreciated.

Thanks!

--and here's the sample xml file--

<library>
<book id="1">
    <title>PHP and MySQL</title>
    <author fname="miguel" lname="alvarez">Miguel Alvarez</author>
</book>
<book id="2">
    <title>JAVA 123</title>
    <author fname="william" lname="vega">WIlliam Vega</author>
</book>

Answer 1

First, you must close the <library> tag, otherwise the XML is malformed and parsing will fail.

SimpleXMLElement::xpath() returns an object (ref), so inside the loop do: echo $node->title.'<br/>';

Getting $albid into string.. well, use string concatenation: $nodes = $xml->xpath('//library/book[@id='.$albid.']');