DvdGiessen/dvdg_wp_embed_oembed_html.php

## dvdg_wp_embed_oembed_html.php
<?php

/**
 * Implementation for WP filter 'embed_oembed_html'.
 * Modifies any iframes in the oEmbed's HTML to use a
 * empty src-attribute, storing the original value in
 * the data-src-attribute. A small piece of JavaScript
 * can restore the src-attribute later.
 * This is particularly useful for example to prevent
 * external sites from setting cookies without the
 * user's permission (EU/NL cookie law).
 *
 * @author Daniël van de Giessen
 * @author Floris P. Lof
 * @params string    $html     The HTML source received from an external API
 *                             (like Twitter, YouTube, Vimeo), in UTF-8 encoding.
 * @params string    $url      The original URI which WP's oEmbed used to call
 *                             the external API.
 * @params array     $attr     Extra attributes (such as width or height).
 * @return string              The HTML source with all iframe's src-tags moved
 *                             to the data-src-attribute.
 */
function my_embed_filter($html, $url, $attr) {
    // Create a new DOMDocument
    $document = new DOMDocument();

    // Load the HTML into the DOMDocument
    @$document->loadHTML('<html><body>' . $html . '</body></html>');

    // Loop over every iframe in the document
    foreach($document->getElementsByTagName('iframe') as $item) {
        if($item instanceof DOMElement && $item->hasAttribute('src') && !$item->hasAttribute('data-src')) {
            // Save the src-attribute's value in the data-src-attribute
            $item->setAttribute('data-src', $item->getAttribute('src'));

            // Empty the src-attribute
            $item->setAttribute('src', '');
        }
    }

    // Save the modified HTML, extract the original code part and return it
    return preg_replace('/^.*<body>(.*)<\/body>.*$/msi', '$1', $document->saveHTML());
}

// Add the filter
add_filter('embed_oembed_html', 'my_embed_filter', 10, 3);
	<?php

	/**
	* Implementation for WP filter 'embed_oembed_html'.
	* Modifies any iframes in the oEmbed's HTML to use a
	* empty src-attribute, storing the original value in
	* the data-src-attribute. A small piece of JavaScript
	* can restore the src-attribute later.
	* This is particularly useful for example to prevent
	* external sites from setting cookies without the
	* user's permission (EU/NL cookie law).
	*
	* @author Daniël van de Giessen
	* @author Floris P. Lof
	* @params string $html The HTML source received from an external API
	* (like Twitter, YouTube, Vimeo), in UTF-8 encoding.
	* @params string $url The original URI which WP's oEmbed used to call
	* the external API.
	* @params array $attr Extra attributes (such as width or height).
	* @return string The HTML source with all iframe's src-tags moved
	* to the data-src-attribute.
	*/
	function my_embed_filter($html, $url, $attr) {
	// Create a new DOMDocument
	$document = new DOMDocument();

	// Load the HTML into the DOMDocument
	@$document->loadHTML('<html><body>' . $html . '</body></html>');

	// Loop over every iframe in the document
	foreach($document->getElementsByTagName('iframe') as $item) {
	if($item instanceof DOMElement && $item->hasAttribute('src') && !$item->hasAttribute('data-src')) {
	// Save the src-attribute's value in the data-src-attribute
	$item->setAttribute('data-src', $item->getAttribute('src'));

	// Empty the src-attribute
	$item->setAttribute('src', '');
	}
	}

	// Save the modified HTML, extract the original code part and return it
	return preg_replace('/^.<body>(.)<\/body>.*$/msi', '$1', $document->saveHTML());
	}

	// Add the filter
	add_filter('embed_oembed_html', 'my_embed_filter', 10, 3);