Extract data-src and data-srcset from img

Question

I am trying to get the data-src and the data-srcset attributes from a string of many images in php. Both attributes are optional, that means, there can be zero, only data-src , only data-srcset or both. The regex I have is

<img(.*?)data-src=['\\"](.*?)['\\"].*?|(data-srcset=['\\"](.*?)['\\"])?\\/>

The string i am testing against is:

<li class="blocks-gallery-item">
  <figure>
    <img data-src="http://localhost:3000/wp-content/uploads/2018/11/detektivhut.gif" alt="" data-id="1037" data-link="http://localhost:3000/detektivhut/" class="wp-image-1037"/>
  </figure>
</li>
<li class="blocks-gallery-item">
  <figure>
    <img data-src="http://localhost:3000/wp-content/uploads/2018/11/DSC04828.png" alt="" data-id="948" data-link="http://localhost:3000/dsc04828-2/" class="wp-image-948" data-srcset="//localhost:3000/wp-content/uploads/2018/11/DSC04828.png 1067w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-200x300.png 200w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-768x1152.png 768w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-683x1024.png 683w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-1000x1500.png 1000w" sizes="(max-width: 1067px) 100vw, 1067px" />
  </figure>
</li>
<li class="blocks-gallery-item">
  <figure>
    <img data-src="http://localhost:3000/wp-content/uploads/2018/11/DSC04831.png" alt="" data-id="883" data-link="http://localhost:3000/2018/11/13/single-page-style-1/dsc04831-2/" class="wp-image-883" data-srcset="//localhost:3000/wp-content/uploads/2018/11/DSC04831.png 1067w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-200x300.png 200w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-768x1152.png 768w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-683x1024.png 683w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-1000x1500.png 1000w" sizes="(max-width: 1067px) 100vw, 1067px" />
  </figure>
</li>

But it is too greedy. Look here:

https://regex101.com/r/vDQE3C/1

Any help (also logical) is very much appreciated.

Answer 1

Don't use regex for parsing html code. Better to use DOM parser like this:

$html = <<< EOF
<li class="blocks-gallery-item">
  <figure>
    <img data-src="http://localhost:3000/wp-content/uploads/2018/11/detektivhut.gif" alt="" data-id="1037" data-link="http://localhost:3000/detektivhut/" class="wp-image-1037"/>
  </figure>
</li>
<li class="blocks-gallery-item">
  <figure>
    <img data-src="http://localhost:3000/wp-content/uploads/2018/11/DSC04828.png" alt="" data-id="948" data-link="http://localhost:3000/dsc04828-2/" class="wp-image-948" data-srcset="//localhost:3000/wp-content/uploads/2018/11/DSC04828.png 1067w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-200x300.png 200w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-768x1152.png 768w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-683x1024.png 683w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-1000x1500.png 1000w" sizes="(max-width: 1067px) 100vw, 1067px" />
  </figure>
</li>
<li class="blocks-gallery-item">
  <figure>
    <img data-src="http://localhost:3000/wp-content/uploads/2018/11/DSC04831.png" alt="" data-id="883" data-link="http://localhost:3000/2018/11/13/single-page-style-1/dsc04831-2/" class="wp-image-883" data-srcset="//localhost:3000/wp-content/uploads/2018/11/DSC04831.png 1067w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-200x300.png 200w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-768x1152.png 768w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-683x1024.png 683w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-1000x1500.png 1000w" sizes="(max-width: 1067px) 100vw, 1067px" />
  </figure>
</li>
EOF;

$xpath = new DOMXPath(@DOMDocument::loadHTML($html));
$images = $xpath->evaluate("//img");

foreach($images as $img){
   if (($el = $img->attributes->getNamedItem('data-src')) != null)
      echo 'data-src=' . $el->nodeValue . "\n";
   if (($el = $img->attributes->getNamedItem('data-srcset')) != null)
      echo 'data-srcset=' . $el->nodeValue . "\n";
}

Output:

data-src=http://localhost:3000/wp-content/uploads/2018/11/detektivhut.gif
data-src=http://localhost:3000/wp-content/uploads/2018/11/DSC04828.png
data-srcset=//localhost:3000/wp-content/uploads/2018/11/DSC04828.png 1067w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-200x300.png 200w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-768x1152.png 768w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-683x1024.png 683w, //localhost:3000/wp-content/uploads/2018/11/DSC04828-1000x1500.png 1000w
data-src=http://localhost:3000/wp-content/uploads/2018/11/DSC04831.png
data-srcset=//localhost:3000/wp-content/uploads/2018/11/DSC04831.png 1067w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-200x300.png 200w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-768x1152.png 768w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-683x1024.png 683w, //localhost:3000/wp-content/uploads/2018/11/DSC04831-1000x1500.png 1000w

Answer 2

You just need to account for anything that comes between the data-attributes* and the image closing tags /> . You needed another (.*?) .

<img(.*?)data-src=['\\"](.*?)['\\"].*?data-srcset=['\\"](.*?)['\\"](.*?)\\/>

And if you only want to capture the data-attributes* consider using non-capturing groups like follows. So that the $1 and $2 variables contain only the data you want, and not the whole image tag.

<img(?:.*?)data-src=['\\"](.*?)['\\"].*?data-srcset=['\\"](.*?)['\\"](?:.*?)\\/>