php - Grabbing the href attribute of an A element

Question

Trying to find the links on a page.

my regex is:

/<as[^>]*href=("'??)([^"' >]*?)[^>]*>(.*)</a>/

but seems to fail at

<a title="this" href="that">what?</a>

How would I change my regex to deal with href not placed first in the a tag?

Answer 1

Reliable Regex for HTML are difficult. Here is how to do it with DOM:

$dom = new DOMDocument;
$dom->loadHTML($html);
foreach ($dom->getElementsByTagName('a') as $node) {
    echo $dom->saveHtml($node), PHP_EOL;
}

The above would find and output the "outerHTML" of all A elements in the $html string.

To get all the text values of the node, you do

echo $node->nodeValue; 

To check if the href attribute exists you can do

echo $node->hasAttribute( 'href' );

To get the href attribute you'd do

echo $node->getAttribute( 'href' );

To change the href attribute you'd do

$node->setAttribute('href', 'something else');

To remove the href attribute you'd do

$node->removeAttribute('href'); 

You can also query for the href attribute directly with XPath

$dom = new DOMDocument;
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$nodes = $xpath->query('//a/@href');
foreach($nodes as $href) {
    echo $href->nodeValue;                       // echo current attribute value
    $href->nodeValue = 'new value';              // set new attribute value
    $href->parentNode->removeAttribute('href');  // remove attribute
}

Also see:

• Best methods to parse HTML
• DOMDocument in php

On a sidenote: I am sure this is a duplicate and you can find the answer somewhere in here