PHP returns element with name instead of ID

Question

In the following PHP code DOMDocument::getElementById returns the node <a name="test">instead of the node <div id="test">:

<?php
$doc = new DOMDocument();
$doc->loadHTML('<a name="test"></a><div id="test"></div>'); // triggers duplicate ID warning
echo $doc->getElementById("test")->nodeName; // outputs "a"
?>

This happens only for <a>nodes. Is this intended?

JavaScript handles it as I expected:

<script>
window.addEventListener('DOMContentLoaded', function() {
    document.body.innerHTML = '<a name="test"></a><div id="test"></div>';
    console.log(document.getElementById('test'));
});
</script>

EDIT (question was marked as duplicate): This question is not about wether I should use name or id and also not about using both name and id, but why PHP finds nodes with name attribute when I search for an id.

See: https://stackoverflow.com/questions/3614586/dom-error-id-someanchor-already-defined-in-entity-line-x — Kazz, Feb 22 '18 at 15:27
Possible duplicate of [HTML Anchors with 'name' or 'id'?](https://stackoverflow.com/questions/484719/html-anchors-with-name-or-id) — Krzysztof Raciniewski, Feb 22 '18 at 15:51
Kenneth Bregat This would just get me the id of the document. I try to get the node with an specific id. Unfortunately I can not change the HTML, but have to parse it and there is another `` node with the name attribute. It is not hard to work around, but I was wondering why it is not working as I expected it. — Toxiro, Feb 22 '18 at 20:45

score 1 · Accepted Answer · answered Feb 22 '18 at 15:32

1

As of HTML5, the name attribute isn't supported in a tags so it looks like it's changed to an id attribute.

answered Feb 22 '18 at 15:32

joelrosenthal

471
4
10

The page I am trying parse is XHTML 1.0, but I guess you are right and PHP does not really care about the Doctype. – Toxiro Feb 22 '18 at 20:52

score 1 · Answer 2 · answered Feb 25 '18 at 01:10

This is most likely a hold-over from PHP emulating old IE behaviour. In IE 7 and earlier, document.getElementById() did indeed treat name attributes on <a> elements as if they were id attributes and so would match the <a> element rather than the <div> element. IE has long since moved on, but PHP it seems, on this point, has not.

score 0 · Answer 3 · edited Jun 20 '20 at 09:12

As you can read here

For HTML documents (and the text/html MIME type), the following processing model must be followed to determine what the indicated part of the document is.

Parse the URL, and let fragid be the component of the URL. If fragid is the empty string, then the indicated part of the document is the top of the document. If there is an element in the DOM that has an ID exactly equal to fragid, then the first such element in tree order is the indicated part of the document; stop the algorithm here. If there is an a element in the DOM that has a name attribute whose value is exactly equal to fragid, then the first such element in tree order is the indicated part of the document; stop the algorithm here. Otherwise, there is no indicated part of the document.

When I pasted your code to PHP sandbox I noticed an interesting warning:

Yes, I have this warning and somehow PHP interprets ` – Toxiro Feb 22 '18 at 20:49 — Toxiro, Feb 22 '18 at 20:49

PHP returns element with name instead of ID

3 Answers3