Regular expression to remove empty <span> tags

Question

Hello, I would like such empty span tags (filled with   and space) to be removed:

<span> &nbsp; &nbsp; &nbsp; </span>

I've tried with this regex, but it needs adjusting:

(<span>(&nbsp;|\s)*</span>)

preg_replace('#<span>(&nbsp;|\s)*</span>#si','<\\1>',$encoded);

Cheers.

Answer 1

.

qr{<span[^>]*(/>|>\s*?</span>)}

Should get the gist of them. ( Including XML style-self closing tags ie: )

But you really shouldn't use regex for HTML processing.

Answer only relevant to the context of the question that was visible before the formatting errors were corrected

Answer 2

Could you explain your solution if possible?

Answer 3

I suppose these span are generated by some program, since they don't seem to have any attribute.
I am perplex why you need to put the space they enclose between angle brackets, but then again I don't know the final purpose of the code.
I think the solution is given by Kent: you have to make the match non-greedy: since you use dotall option (s), you will match everything between the first span and the last closing span!

So the answer should look like:

preg_replace('#<span>(&nbsp;|\s)*?</span>#si', '<$1>', $encoded);

(untested)

Answer 4

purpose: I'm trying to filter out directly pasted MS-WORD content.

P.S. I've tried the code above - the empty space still stays untouched...

Answer 5

The problem comes when the span gets nested like: <span><span> &nbsp; </span></span>

Answer 6

Translating Kent Fredric's regexp to PHP :

preg_match_all('#<span[^>]*(?:/>|>(?:\s|&nbsp;)*</span>)#im', $html, $result);

This will match :

• autoclosing spans
• spans on multilines and whatever the case
• spans with attributes
• span with unbreakable spaces

Maybe you should about including spans containings only
as well...

As usual, when it comes to tweak regexp, some tools are handy :

http://regex.larsolavtorvik.com/

Answer 7

I've tried with this regex, but it needs adjusting:

In what way does the regex in the original question fail?

The problem comes when the span gets nested like: <span><span> &nbsp; </span></span>

This is an example of why using regexes to parse HTML doesn't work particularly well. Depending on your regex flavor, this situation is either impossible to handle in a single pass or merely very difficult. I don't know PHP's regex engine well enough to say which category it falls into, but, if the only problem is that it takes out the inner <span> and leaves the outer one alone, then you may want to consider simply re-running your substitution repeatedly until it runs out of things to do.

Answer 8

Simply a good site when working with regular expressions, Regex http://regexlib.com/. Tester and cheat sheet very helpful

Answer 9

If your only issue are nested span tags, you can run the search-and-replace with the regex you have in a loop until the regex no longer finds any matches.

This may not be a very elegant solution, but it'll perform well enough.

Answer 10

Here is my solution to nesting tags problems, still not complete but close...

$test="<span>   <span>& nbsp;  </span> test <span>& nbsp; <span>& nbsp;  </span>  </span> & nbsp;& nbsp; </span>";

$pattern = '#<(\w+)[^>]*>(& nbsp;|\s)*</\1>#im';      
while(preg_match($pattern, $test, $matches, PREG_OFFSET_CAPTURE)!= 0)
{$test= preg_replace($pattern,'', $test);}

For short $test sentences the function works OK. Problem comes when trying with a long text. Any help will be appreciated...