Regular expression for tag replacement

Question

I'm new to regular expressions, but I'm trying to learn about it. I want to remove the tag of a html text, and let only the inner text. Something like that:

Original: Lorem ipsum <a href="http://www.google.es">Google</a> Lorem ipsum <a href="http://www.bing.com">Bing</a>
Result:  Lorem ipsum Google Lorem ipsum Bing

I'm using this code:

$patterns = array( "/(<a href=\"[a-z0-9.:_\-\/]{1,}\">)/i", "/<\/a>/i");
$replacements = array("", "");

$text = 'Lorem ipsum <a href="http://www.google.es">Google</a> Lorem ipsum <a href="http://www.bing.com">Bing</a>';
$text = preg_replace($patterns,$replacements,$text);

It works, but I don't know if this code is the more efficient or the more readable.

Can I improve the code in some way?

Answer 1

In your case, PHP's strip_tags() should do exactly what you need without regular expressions. If you want to strip only a specific tag (something strip_tags() can't do by default), there is a function in the User Contributed Notes.

In general, regexes are not suitable for parsing HTML. It's better to use a DOM parser like Simple HTML DOM or one of PHP's built-in parsers.

Answer 2

Don't use regular expressions, use a DOM parser instead.

Answer 3

If your content only contains anchor tags, then strip_tags is probably easier to use.

Your preg_replace won't replace if there are spurious spaces between a and href, or if there are any other attributes in the tag.

Answer 4

In this case, using regex is not a good idea. Having said that:

<?php
    $text = 'Lorem ipsum <a href="http://www.google.es">Google</a> Lorem ipsum <a href="http://www.bing.com">Bing</a>';
    $text = preg_replace(
        '@\\<a\\b[^\\>]*\\>(.*?)\\<\\/a\\b[^\\>]*\\>@',
        '\\1',
        $text
    );
    echo $text;
    // Lorem ipsum Google Lorem ipsum Bing
?>

This is a very trivial regex, its not bullet proof.

Answer 5

You can't parse [X]HTML with regex.