How to extract elements with XMLReader - php

Question

I have a large XML file (4GB) which I'm parsing and importing in to a database. I've been playing with XMLReader but can't seem to get it to work and the PHP documentation doesn't have many examples to work with.
My goal is to extract combinations of "url" and "text" from the following (simplified) version of the XML file I'm working with:
<everything>
<doc>
<field1>...</field2>
<url>www.theurlthatIwant.com</url>
<text>This is some text which I want to extract with the url</text>
<random>
<subrandom> </subrandom>
<subrandom> </subrandom>
<subrandom> </subrandom>
</random>
</doc>
<doc>
<field1>...</field2>
<url>www.anotherurl.com</url>
<text>This is some more text which I want to extract with the url</text>
<random>
<subrandom> ... </subrandom>
<subrandom> ... </subrandom>
<subrandom> ... </subrandom>
</random>
</doc>
...
</everything>
What's the pseudocode for grabbing "url" and "text" and ignoring the rest using XMLReader? I plan on outputting the pairs to a CSV file for further (much easier) processing. Thank you!
Updated:
Figured it out, posting answer below for future readers.

Answer 1

I got it working finally. What I didn't understand is that read() doesn't just move to the next element, it moves to the next TOKEN, which could be text, a closing tag, or any XML element. Here's the working code for future readers:
$xml = new XMLReader;
$xml->open('data.xml');
$xml->read(); // One read to skip the "everything" element
while ($xml->read()) {
if ($xml->nodeType == XMLReader::ELEMENT) {
if ($xml->name == 'url') {
$xml->read();
if ($xml->nodeType == XMLReader::TEXT) {
print 'got url: ' . $xml->value.PHP_EOL;
}
}elseif ($xml->name == 'text') {
$xml->read();
if ($xml->nodeType == XMLReader::TEXT) {
print 'got text: ' . $xml->value.PHP_EOL;
}
}
}
}