email-image-embedder.php

<?php

// ------------------------
// Email Image AutoEmbedder
// ------------------------

add_action('phpmailer_init', 'email_images_embedder');

function email_images_embedder($phpmailer) {

	// --- bug out if just text body ---
	$content_type = $phpmailer->ContentType;
	$text_types = array('text/plain', 'text', 'txt', 'plaingtext');
	if (in_array($content_type, $text_types)) {return;}

	// --- get the HTML message body ---
	$message_body = $phpmailer->Body;

	// --- search for image tag matches ---
	$pattern = '/<*img[^>]*src *= *["\']?([^"\']*)/i';
	preg_match_all($pattern, $message_body, $found_images);
	$imageurls = $found_images[1];

	// --- bug out if no image matches found ---
	if (count($imageurls) == 0) {return;}

	// --- remove duplicates for processing ---
	$imageurls = array_unique($imageurls);

	// --- get uploads base path ---
	$siteurl = site_url();
	$uploads = wp_upload_dir(null, false); // (wp_get_upload_dir)
	$paths['uploads']['dir'] = $uploads['basedir'];
	$paths['uploads']['url'] = $uploads['baseurl'];

	// --- get possible plugin settings ---
	// (can modify prefixes to match plugin options)
	$images_url = get_option('email_images_url');
	$images_dir = get_option('email_images_dir');
	if ($images_url && $images_dir) {
		$paths['settings']['dir'] = $images_dir;
		$paths['settings']['url'] = $images_url;
	}

	// --- filter paths for custom usage ---
	$paths = apply_filters('email_image_paths', $paths);

	// --- loop found images ---
	$j = 0; $uids = array();
	foreach ($imageurls as $i => $url) {

		// --- generate unique image ID ---
		$uid = 'image'.rand(0, 999999);
		if (in_array($uid, $uids)) {
			while (in_array($uid, $uids)) {
				$uid = 'image'.rand(0, 999999);
			}
			$uids[] = $uid;
		}

		// --- check in upload and image directories ---
		$filepath = false;
		foreach ($paths as $pathname => $path) {
			$checkpath = str_replace($path['url'], $path['dir'], $url);
			if (file_exists($checkpath)) {$filepath = $checkpath; break;}
		}

		// --- maybe attempt manual base path matching ---
		if (!$filepath) {
			if (strpos($url, $siteurl) === 0) {
				$checkpath = str_replace($siteurl, ABSPATH, $url);
				if (file_exists($checkpath)) {$filepath = $checkpath;}
			}
		}

		// --- set image data ---
		if ($filepath) {
			$images[$j] = array(
				'url'		=> $url,
				'uid'		=> $uid,
				'filepath'	=> $filepath,
				'filename'	=> basename($filepath)
			);
			$j++;
		}

	}

	// --- loop to add embedded images ---
	foreach ($images as $j => $image) {

		// --- replace image URL with cid in message body ---
		$message_body = str_replace($image['url'], "cid:".$image['uid'], $message_body);

		// --- embed image via phpmailer ---
		$phpmailer->AddEmbeddedImage($image['filepath'], $image['uid'], $image['filename']);
	}

}