Newline to BR (not using nl2br())

How would I convert a section of text including HTML code (from, say, a database) so that newlines were preceeded with <br> (or the XHTML comlient <br />) but didn't put these linebreak tags in the middle of other HTML tags such as <img> tags?

nl2br() will change:
This is
some text
<img src="http://blah.com/img.gif"
title="Image">
into
This is<br />
some text<br />
<img src="http://blah.com/img.gif"<br />
title="Image">
The <img> tag will obviously not work with the line break stuck in the middle of it.

After a bit of thiking I came to the conclusion that I'd have to use a Regex but the precise regex eluded me and continues to do so. Therefore I have turned to others for help :D

Thanks in advance :)

I hate these type of answers ;) , but the best bet would be to not put the newlines into the DB in the first place ?

nl2br(); only adds a break where a newline exists , no linebreak == no <BR/>

we have at least one resident regex guru ... but if you are using regex anywhere I would suggest you should be doing it B4 you add to the database , not at display time.

Yeah I thought that using the regex before adding to the database would be faster etc but whether it's while inserting or while displaying i still need the regex ;)

Currently I have to enter the <br> tags manually while typing into the textarea which is a bit of a pain, I was just trying to make things easier.

Any regex I came up with myself managed to match either ALL the instances of <br> or NONE of them (this was after the nl2br()), neither of which are particularly useful...

The difficult part is to locate those tags which contain newlines, the replacement functionality is easy then. Here's a quick hack that shows one way to do this:


$str = 'This <b id="
foo">is</b>
some text
<img src="http://blah.com/img.gif"
title="Image">';

function stripNewlines($matches) {
// replace newlines
$tag = str_replace(array("\n", "\r"), '', $matches[0]);
// add spaces between very near standing attributes
$tag = preg_replace('/([^=])(["\'])(\w)/', '\1\2 \3', $tag);

return $tag;
}

function cleanText($text) {
return preg_replace_callback('/<.*?\n.*?>/', "stripNewlines", $text);
}


// test output
var_dump(cleanText($str));
echo "\n\n";
var_dump(nl2br(cleanText($str))); // how it looks like after nl2br() is applied to the text


Note: The forum software tends to strip special characters from regexes. If you don't get the desired output, tell me, and I try to upload a correct version.