使用PHP DOMXpath遍历子节点？

Question

I'm having some trouble understanding what exactly is stored in childNodes. Ideally I'd like to do another xquery on each of the child nodes, but can't seem to get it straight. Here's my scenario: Data:

<div class="something">
    <h3>
        <a href="link1.html">Link text 1</a>
    </h3>
    <div class"somethingelse">Something else text 1</div>
</div>
<div class="something">
    <h3>
        <a href="link2.html">Link text 2</a>
    </h3>
    <div class"somethingelse">Something else text 2</div>
</div>
<div class="something">
    <h3>
        <a href="link3.html">Link text 3</a>
    </h3>
    <div class"somethingelse">Something else text 3</div>
</div>

And the code:

$html = new DOMDocument();
$html->loadHtmlFile($local_file);
$xpath = new DOMXPath( $html );
$nodelist = $xpath->query( "//div[@class='something']");
foreach ($nodelist as $n) {
    Can I run another query here? }

For each element of "something" (ie, $n) I want to access the values of the two pieces of text and the href. I tried using childNode and another xquery but couldn't get anything to work. Any help would be greatly appreciated!

Answer 1

Yes you can run another xpath query, something like that :

foreach ($nodelist as $n)
{
    $other_nodes = $xpath->query('div[@class="somethingelse"]', $n);

    echo $other_nodes->length;
}

This will get you the inner div with the class somethingelse, the second argument of the $xpath->query method tells to query to take this node as context, see more http://fr2.php.net/manual/en/domxpath.query.php

Answer 2

Trexx had it but he missed the last sentence of the question:

foreach ($nodelist as $n){
    $href = $xpath->query('h3/a', $n)->item(0)->getAttribute('href');
    $a_text = $xpath->query('h3/a', $n)->item(0)->nodeValue;
    $div_text = $xpath->query('div', $n)->item(0)->nodeValue;
}

Answer 3

If I understand your question correctly, it worked when I used the descendant:: expression. Try this:

foreach ($nodelist as $n) {
    $other_nodes = $xpath->query('descendant::div[@class="some-descendant"]', $n);

    echo $other_nodes->length;
    echo $other_nodes->item(0)->nodeValue;
}

Although sometimes it's just enough to combine queries using the // path expression for narrowing your search. The // path expression selects nodes in the document starting from the current node that match the selector.

$nodes = $xpath->query('//div[@class="some-descendant"]//div[@class="some-descendant-of-that-descendant"]');

Then loop through those for the stuff you need. Hope this helps.

Answer 4

Here is a code snippet that allows you to access the information contained within each of the nodes with class attribute "something":

$nodes_tracker = 0;
$nodes_array = array();
foreach($nodelist as $n){
    $info = $xpath->query('//h3//a', $n)->item($nodes_tracker)->nodeValue;
    $extra_info = $xpath->query('//div[@class="somethingelse"', $n)->item($nodes_tracker)->nodeValue;
    array_push($nodes_array, $info. ' - '. $extra_info . '<br>'); //Add each info to array  
    $nodes_tracker++;
}
print_r($nodes_array);`