Getting element names/values with XML/Xpath/PHP - php

Question

I have an XML schema that looks as follows:
<xml>
<user id="1">
<first_name>Bill</first_name>
<last_name>Steve</last_name>
<phone_numbers>
<work>xxx-xxx-xxxx</work>
<home>xxx-xxx-xxxx</home>
</phone_numbers>
</user>
<user id="2">
........
</user>
</xml>
Im working on parsing all of this information into PHP using DOM. Ex.
$userInfo = $doc->getElementsByTagName( "user" );
foreach($userInfo as $row)
{
$first_name = $row->getElementsByTagName("first_name");
}
When I try to nest this to select the phone numbers however I get an error. I've tried using XPath to select the phone numbers with equal problems. I tried something along the lines of
$userInfo = $doc->getElementsByTagName( "user" );
foreach($userInfo as $row)
{
$phoneInfo = $row->getElementsByTagName("phone_numbers");
foreach($phoneInfo as $row2)
{
$work = $row2->getElementsByTagName("work");
}
}
Im curious if Im doing something fundamentally wrong, or how to get this going. I've been tearing my hair out for a few hours now.

Answer 1

You can't get the value directly from a DOMNodeList Object, try this :
$userInfo = $doc->getElementsByTagName( "user" );
foreach($userInfo as $row)
{
$phoneInfo = $row->getElementsByTagName("phone_numbers");
foreach($phoneInfo as $row2)
{
// get the value from the first child
$work = $row2->getElementsByTagName("work")->item(0)->nodeValue;
$home = $row2->getElementsByTagName("home")->item(0)->nodeValue;
}
}

Answer 2

Well, you could switch it to SimpleXml which makes this type of parsing easier:
$userInfo = $doc->getElementsByTagName( "user" );
foreach ($userInfo as $user) {
$node = simplexml_import_dom($user);
$id = (string) $node['id'];
$first = (string) $node->first_name;
$last = (string) $node->last_name;
$workPhone = (string) $node->phone_numbers->work;
$homePhone = (string) $node->phone_numbers->home;
}
Now, in DomDocument, you could do this by using DomXpath:
$userInfo = $doc->getElementsByTagName( "user" );
$xpath = new DomXpath($doc);
foreach ($userInfo as $user) {
$id = $user->getAttribute('id');
$first = $xpath->query('//first_name', $user)->item(0)->textContent;
$last = $xpath->query('//last_name', $user)->item(0)->textContent;
$work = $xpath->query('//phone_numbers/work', $user)->item(0)->textContent;
$home = $xpath->query('//phone_numbers/home', $user)->item(0)->textContent;
}
Note that the above code (both parts) require that the format is exactly that. If you have conditionals, you might want to change it to something like this (the firstname conditional only):
$userInfo = $doc->getElementsByTagName( "user" );
$xpath = new DomXpath($doc);
foreach ($userInfo as $user) {
$id = $user->getAttribute('id');
$firstQuery = $xpath->query('//first_name', $user);
if ($firstQuery->length > 0) {
$first = $firstQuery->item(0)->textContent;
} else {
$first = '';
}
}