class-external-link-builder.php

<?php
new External_Link_Builder();

/**
 * Class Name: External Link Builder
 *@author @ottanxyz
 */
class External_Link_Builder {

	function __construct() {
		wp_embed_register_handler(
			'external_link_builder',
			'/(http(s?):\\/\\/.*)$/i',
			array( &$this, 'handler' )
		);
		add_shortcode( 'external_links', array( &$this, 'display' ) );
	}

	public function handler( $matches, $attr, $url, $rawattr ) {
		$args = preg_split( '/#/', $matches[1] );
		return "[external_links url=\"{$args[0]}\"]";
	}

	public function display( $p ) {
		if ( ! isset( $p['url'] ) || ! $p['url'] ) {
			return;
		}

		if ( false === ( $results = get_transient( 'external-' . urlencode( $p['url'] ) ) ) ) {
			require_once dirname( __FILE__ ) . '/../lib/OpenGraph.php';

			$graph = OpenGraph::fetch( $p['url'] );

			global $post;
			$results = array();

			if ( isset( $graph->image ) ) {
				$image_url = $this->_media_handle_sideload( $graph->image, $post->ID );
			} else {
				$image_url = get_template_directory_uri() . '/img/m_e_others_501.png';
			}

			if ( isset( $graph->site_name ) ) {
				$site_name = $graph->site_name;
			} else {
				$site_name = parse_url( $p['url'] );
				$site_name = $site_name['host'];
			}

			$results['image_url'] = $image_url;
			$results['permalink'] = $p['url'];
			$results['title'] = $graph->title;
			$results['description'] = $graph->description;
			$results['site_name'] = $site_name;

			set_transient( 'external-' . urlencode( $p['url'] ), $results, YEAR_IN_SECONDS );
		}

		$permalink = $results['permalink'];
		$title = $results['title'];
		$image_url = $results['image_url'];
		$site_name = $results['site_name'];

		if ( isset( $results['description'] ) ) {
			$description = mb_substr( str_replace( array( "\r\n", "\r", "\n" ), '', strip_tags( $results['description'] ) ), 0, 120 ) . '... ';
		} else {
			$description = '';
		}

		return <<< EOM
<div class="wp-embed">
<div class="wp-embed-featured-image square">
<a href="${permalink}" target="_top">
<img src="${image_url}" class="attachment-top-thumbnail size-top-thumbnail" alt="${title}"></a>
</div>
<p class="wp-embed-heading"><a href="${permalink}" target="_top">${title}</a></p>
<div class="wp-embed-excerpt"><p>${description}<a href="${permalink}" class="wp-embed-more" target="_top">続きを読む</a></p></div>
<div class="wp-embed-footer">
<div class="wp-embed-site-title"><a href="${permalink}" target="_top"><span>${site_name}</span></a></div>
</div>
</div>
EOM;
	}

	private function _media_handle_sideload( $url, $post_id ) {

		if ( ! function_exists( 'media_handle_sideload' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
			require_once ABSPATH . 'wp-admin/includes/media.php';
			require_once ABSPATH . 'wp-admin/includes/image.php';
		}
		/*
		 * Build the $file_array with
		 * $url = the url of the image
		 * $temp = storing the image in wordpress
		 */
		$url = explode( '?', $url );
		$tmp = download_url( $url[0] );

		$file_array = array(
			'name' => basename( $url[0] ),
			'tmp_name' => $tmp,
		);

		/**
		 * Check for download errors
		 * if there are error unlink the temp file name
		 */
		if ( is_wp_error( $tmp ) ) {
			unlink( $file_array['tmp_name'] );
			return $tmp;
		}

		/**
		 * now we can actually use media_handle_sideload
		 * we pass it the file array of the file to handle
		 * and the post id of the post to attach it to
		 * $post_id can be set to '0' to not attach it to any particular post
		 */

		$id = media_handle_sideload( $file_array, $post_id );
		/**
		 * We don't want to pass something to $id
		 * if there were upload errors.
		 * So this checks for errors
		 */
		if ( is_wp_error( $id ) ) {
			unlink( $file_array['tmp_name'] );
			return $id;
		}

		/**
		 * No we can get the url of the sideloaded file
		 * $value now contains the file url in WordPress
		 * $id is the attachment id
		 */
		return wp_get_attachment_url( $id );
	}
}
?>