Question

I am getting this error,

Warning: SimpleXMLElement::xpath() [simplexmlelement.xpath]: Invalid expression.

Searched in internet but could not remove this error. That is im posting it one more time.

Here is my php code:

<?php
            $file = $_POST['id'];
            $xml = simplexml_load_file('test.xml');

            $user = $xml->xpath("user[user_id == $id]");             
            $name = $user->name;
            $file = $user->file;
            echo 'Name' . $name;
            echo 'File Name' . $file;
?>
        <form action='<?php echo $_SERVER['PHP_SELF']?>' method="POST">
            Login ID: <input type="text" name="id" />
            <input type="submit" name="submit" value="Submit"/>               
        </form> 

And my test.xml file is:

<?xml version="1.0" encoding="ISO-8859-1"?>
<document>
    <user>
        <user_id>0121</user_id>
        <name>Tim</name>
        <file>0121.file</file>
    </user>
    <user>
        <user_id>0178</user_id>
        <name>Henry</name>
        <file>0178.file</file>
    </user>
    <user>
        <user_id>0786</user_id>
        <name>Martin</name>
        <file>0786.file</file>
    </user>
    <user>
        <user_id>1239</user_id>
        <name>Jan</name>
        <file>1239.file</file>
    </user>
</document>

Any reason?

Thanks
Raaks

Answer 1

== is the invalid expression. Try this:

 $user = $xml->xpath("user[user_id=$id]");