Regular expression: Replace contents of
tag with
tag if no data inside

Question

Code:

    <div>
      <font face="Arial, Verdana">
         <span style="font-size: 13.3333px;">
           <u>
             Hello World
           </u>
       </span>
    </font>
 </div>
    <div>
      <font face="Arial, Verdana">
         <span style="font-size: 13.3333px;">
           <u>
            Hello World2
           </u>
            <br>
       </span>
    </font>
 </div>
 <div>
    <br>
 </div>
 <div>
      <font face="Arial, Verdana">
        <span style="font-size: 13.3333px;">
           <u>
               <br>
            </u>
        </span>
      </font>
 </div>

Output:- I wish to get exactly the same output as given below

    <div>
      <font face="Arial, Verdana">
         <span style="font-size: 13.3333px;">
            <u>
             Hello World
            </u>
          </span>
       </font>
     </div>
    <div>
      <font face="Arial, Verdana">
         <span style="font-size: 13.3333px;">
           <u>
            Hello World2
           </u>
            <br>
       </span>
    </font>
 </div>
 <br>
 <br>

Here is what I have tried:

$html = preg_replace("/<div.*?>.*?<br.*?>.*?<\/div>/", "", $html);

but it is not working fine.

Please take a look on the code and suggest me how I can replace "div" tag from its starting to corresponding closing tag with "br" tag only when there is no text is present under "div" tag. As shown above in second "div" tag.

I have tried this: $html = preg_replace("/.*?.*?<\/div>/", "", $html); but It is not working fine... — Ram goel, Apr 29 '16 at 16:18

score 2 · Answer 1 · answered Apr 29 '16 at 16:39

2

use domDocument to manipulate with html structure

$doc = new DOMDocument();
$doc->loadHtml($pageHtml);
$x = new DOMXpath($doc);
foreach($x->query('//div[normalize-space(.) = ""]') as $div) {
    $link= $doc->createElement('br');
    $div->parentNode->replaceChild($link, $div);
}

echo $doc->saveHTML();

demo

answered Apr 29 '16 at 16:39

splash58

26,043
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1

1UP for `//div[normalize-space(.) = ""]` – Pedro Lobito Apr 29 '16 at 16:45
@PedroLobito Agreed - super elegant! – Nate I Apr 29 '16 at 16:48
1

@PedroLobito Thanks a lot. – Ram goel Apr 29 '16 at 17:42
Glad to help. You can accept an answer which you found as helpful. – splash58 Apr 29 '16 at 17:45
@PedroLobito: This code is working fine on my PC but on server I am having PHP 5.1.6 and in that DOMDocument class does not exist. Can you please suggest me any package I can install without upgrading the PHP on Server. – Ram goel Apr 30 '16 at 05:54
1

@Ramgoel look that - http://stackoverflow.com/questions/5494317/php-domdocument-missing and – splash58 Apr 30 '16 at 06:13

score 2 · Accepted Answer · edited May 23 '17 at 12:31

I would highly suggest using DOM Manipulation to accomplish this. You can use regular expressions and you can make other solutions work. However, DOM Manipulation was created for this exact reason.

There are many examples of DOM Parsers in PHP. Some are slower than others. Check out this SO post for a great listing of potential candidates for DOM Parsers.

You could always use Regular Expressions - but here's the condition under which I would personally use a Regular Expression: If you never plan to add any other functionality to this. If you do plan to add more, change it up, make your script more versatile, etc., then I'd say don't use a RegEx. The reason is you will either end up with a huge, completely daunting expression, or you'll end up with many small "one-off" expressions. It will take you less time to reference a function inside a DOM Parser than it will to figure out the proper Regular Expression.

EDIT:

I've removed my code snippet - Splash58's answer is a more elegant solution. His example uses native PHP which 9.9 times out of 10 is better (quicker, more efficient, more community support, etc).

agree strongly with the 'no extra functionality' limitation. — Ryan Vincent, Apr 29 '16 at 16:55

Regular expression: Replace contents of tag with tag if no data inside

2 Answers2

Regular expression: Replace contents of
tag with
tag if no data inside