从img中提取数据.src和data.srcset

Question

我正在尝试从php中的多个图像字符串中获取data-src和data-srcset属性。这两个属性都是可选的，这意味着可以有零，只有data-src，只有data-srcset或两者都有。我的准则是

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

我测试的字符串是：

<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>

但它太贪婪了。看这里：

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

任何帮助(也是合乎逻辑的)都非常感谢。

Answer 1

不要使用regex来解析html代码。最好像这样使用DOM解析器：

$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";
}

输出：

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

您只需要说明data-attributes*和图像结束标记/>之间的任何内容。你需要另一个(.*?)。

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

如果您只想捕获data-attributes*，请考虑使用非捕获组，如下所示。因此，$1和$2变量只包含所需的数据，而不是整个图像标记。

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