Remove paragraph by id with PHP DOM

1
votes

I'm trying to find paragraphs with the id "test" and remove them from a html string, I've tried using php DOMDocument but the html I'm searching is badly formed and I get errors

$caption = "blah blah<p id ='test'>Test message</p>";
$doc = new DOMDocument();
$doc->loadHTMLFile($caption);
$xmessage = $doc->getElementById('test');

returns

Warning: DOMDocument::loadHTML() [domdocument.loadhtml]: Unexpected end tag : br i

Is there a way to suppress the warnings? Thanks

4
phpdomdocument

4 Answers

4
votes

You can use following code to remove a para with id='test':

$caption = "blah blah<p id='test'>Test message</p><p id='foo'>Foo Bar</p>";
$doc = new DOMDocument();
$doc->loadHTML($caption);
$xpath = new DOMXPath($doc);
$nlist = $xpath->query("//p[@id='test']");
$node = $nlist->item(0);
echo "Para: [" . $node->nodeValue . "]\n";
$node->parentNode->removeChild($node);
echo "Remaining: [" . $doc->saveHTML() . "]\n";

OUTPUT:

Para: [Test message]
Remaining: [<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html><body>
<p>blah blah</p>
<p id="foo">Foo Bar</p>
</body></html>
]
3
votes

Don't use loadHTMLFile() use loadHTML().

The latter expects HTML string, which is what you are providing. Doing so should correct the warning.

1
votes

getElementById requires the HTML to be validated before it'll work. See this StackOverflow answer for more info.

$caption = "blah blah<p id ='test'>Test message</p>";
$doc = new DOMDocument;
$doc->validateOnParse = true;  // validate HTML
$doc->loadHTML($caption);  // This loads an HTML string
$xmessage = $doc->getElementById('test');

(NOTE: You need to use loadHTML, not loadHTMLFile).

This still may not work, as the HTML may not be valid.

If this doesn't work, I suggest using DOMXPath.

$caption = "blah blah<p id ='test'>Test message</p>";
$doc = new DOMDocument;
$doc->loadHTMLFile($caption);
$xpath = new DOMXPath($doc);
$xmessage = $xpath->query("//p[@id='test']")->item(0);
-1
votes

There's more than one paragraph with the same ID? Surely not...

It's generally bad practice (as the warnings are there for a reason), but you can suppress warnings using @, although i'm not 100% certain it works on function calls from a class like this, let me know if it does!

$caption = "blah blah<p id ='test'>Test message</p>";
$doc = new DOMDocument();
@$doc->loadHTMLFile($caption);
$xmessage = @$doc->getElementById('test');