wp-content-image-regex.php

<?php
/**
 * Update Single Post Content images to include image credit
 *
 * @param  string $content
 * @return string
 */
function _codeable_addCreditToImage(string $content){
	global $post;
	
	// Get all images from post content
    preg_match_all("/<img(.*?)class=('|\")(.*?)('|\")(.*?)src=('|\")(.*?)('|\")(.*?)>/i", $content, $images);

	// check if images exist. If not, exit.
    if(!is_null($images)){
		$i = 0;
		
		// Loop through images
        foreach ($images as $key) {
			
			// Get the class and match just the image ID.
			$class = $images[3][$i];
			preg_match('/(\d+)[^-]*$/', $class, $pictureID);
			
			// Set the image ID and check for Credit Line Post Meta
			$imageID = $pictureID[0];
			$credit_line = get_post_meta($imageID, 'sanfrancisco_credit_line', true );
			
			// Do we have Credit Line?
			if($credit_line){
			
				// Format the image with a credit line
				$replacement = "<figure class='has-credit-line'>
					<img ".$images[1][$i]." class=".$images[2][$i].$images[3][$i].$images[4][$i].$images[5][$i]." src=".$images[6][$i].$images[7][$i].$images[8][$i].$images[9][$i].">
					<div class='sf-entry-flags'>
						<span class='sf-entry-flag sf-entry-flag-creditline'>" . get_post_meta($imageID , 'sanfrancisco_credit_line', true ) . "</span>
					</div>
				</figure>";

				// replace the content with the new images
				$content = str_replace($images[0][$i], $replacement, $content);
			}
			$i++;
        }
    }

    return $content;
}
add_filter('the_content', '_codeable_addCreditToImage', 9999);
?>