逃避<br />

Question

I'm trying to escape <br /> and the likes in my Magento meta description.

So I've come up with this:

$characters = array("<br />", "<br>", "<br/>");
$badDesc = htmlspecialchars($this->getDescription());
$goodDesc = preg_replace($characters, ' ', $badDesc);

but the only characters thats escaped is "br /", but remaining is the "< >"

What do?

Answer 1

Perhaps this is worth a shot (note: untested)

$desc = preg_replace('/\<br\b[^>]*>/i', ' ', $this->getDescription());

The expression explained:

• \<br is a literal match for the string <br
• \b is a word boundary: preg_match('/foo\bbar/', 'foobar') will not match, but preg_match('/foo\bbar/', 'foo bar') will match. That is, in essence a word-boundary. The beginning and ending of a word
• [^>]* matches all chareacters except for a literal >. The asterisk states that this character class may occur zero or more times: with <br />, for example, this char class will match / (all spaces and the forward slash. Given this: <br>, then this part will be skipped (occurs zero times)
• > is a litteral match for the close-tag > char

If your markup is valid (ie not malformed), this expression will remove nothing you don't want to remove. But given strings like this: <br data-string="<b>Don't include markup here</b>"/> this expression will fail: there is a property that contains markup, but that is something I, personally, find revolting. You don't include markup in an attribute of a tag, IMO.
Another case where regex lets the guard down is when encountering malformed markup:

<br/The closing &gt; was omitted</p>

The regex will match the opening <br, then the [^>]* will match:

/The closing &gt; was omitted</p

Only to match the > of </p> as the end of the br tag. But that's just the "fault" of whoever wrote the markup...