How do I iterate through DOM elements in PHP?

Question

I have an XML file loaded into a DOM document, I wish to iterate through all 'foo' tags, getting values from every tag below it. I know I can get values via

$element = $dom->getElementsByTagName('foo')->item(0);
foreach($element->childNodes as $node){
    $data[$node->nodeName] = $node->nodeValue;
}

However, what I'm trying to do, is from an XML like,

<stuff>
  <foo>
    <bar></bar>
      <value/>
    <pub></pub>
  </foo>
  <foo>
    <bar></bar>
    <pub></pub>
  </foo>
  <foo>
    <bar></bar>
    <pub></pub>
  </foo>
  </stuff>

iterate over every foo tag, and get specific bar or pub, and get values from there. Now, how do I iterate over foo so that I can still access specific child nodes by name?

roryf · Accepted Answer · 2008-10-10T18:03:45.597

45

Not tested, but what about:

$elements = $dom->getElementsByTagName('foo');
$data = array();
foreach($elements as $node){
    foreach($node->childNodes as $child) {
        $data[] = array($child->nodeName => $child->nodeValue);
    }
}

edited Oct 10 '08 at 18:03

answered Oct 10 '08 at 15:56

roryf

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1

No need for $elementCount. Just append to $data like this: $data[] = array($child->nodeName => $child->nodeValue); – troelskn Oct 10 '08 at 16:01
1

That did the trick! I was thinking too complicated. Must be tired. – Esa Oct 10 '08 at 16:08
Updated the code based on comment from troelskn, is that what you meant? – roryf Oct 10 '08 at 18:04
@Rory: Yes, that's what I meant. – troelskn Oct 10 '08 at 22:30

score 4 · Answer 2 · answered Oct 10 '08 at 20:23

It's generally much better to use XPath to query a document than it is to write code that depends on knowledge of the document's structure. There are two reasons. First, there's a lot less code to test and debug. Second, if the document's structure changes it's a lot easier to change an XPath query than it is to change a bunch of code.

Of course, you have to learn XPath, but (most of) XPath isn't rocket science.

PHP's DOM uses the xpath_eval method to perform XPath queries. It's documented here, and the user notes include some pretty good examples.

score 2 · Answer 3 · edited May 09 '14 at 13:32

2

Here's another (lazy) way to do it.

$data[][$node->nodeName] = $node->nodeValue;

edited May 09 '14 at 13:32

Chris

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answered Dec 09 '08 at 16:29

Daniele Orlando · Answer 4 · 2016-03-07T16:33:25.540

-2

With FluidXML you can query and iterate XML very easly.

$data = [];

$store_child = function($i, $fooChild) use (&$data) {
    $data[] = [ $fooChild->nodeName => $fooChild->nodeValue ];
};

fluidxml($dom)->query('//foo/*')->each($store_child);

https://github.com/servo-php/fluidxml

edited Mar 07 '16 at 16:33

answered Jan 24 '16 at 01:15

Daniele Orlando

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How do I iterate through DOM elements in PHP?

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