將文章中嵌入的 YouTube 影片加入複合式摘要中

<?php
/**
 * Add Rich Snippets when YouTube videos are detected in posts.
 */
if ( !function_exists( 'hyc_youtube_post' ) ) :
	function hyc_youtube_post(){
		if ( 'post' !== get_post_type() ){
			return;
		}
		global $post;
		$content = $post->post_content;
		$yt_regex = '/(youtu\.be\/|youtube\.com\/(watch\?(.*&)?v=|(embed|v)\/))([-_\w]+)/';
		preg_match_all( $yt_regex, $content, $matches, PREG_SET_ORDER );
		foreach( $matches as $match ){
			$ids[] = $match[5];
		} 
		$api_url = add_query_arg( array(
			'id'     => implode( ',', array_unique( $ids ) ),
			'part'   => 'contentDetails,snippet',
			'key'    => '{{YOUR GOOGLE API KEY}}',
			), esc_url( 'https://www.googleapis.com/youtube/v3/videos' ) );
		$returns = json_decode( wp_remote_get( $api_url )['body'] );
		foreach ( $returns->items as $return ){
			$request[$return->id] = array(
				'@context'    => 'https://schema.org',
				'@type'       => 'VideoObject',
				'name'        => $return->snippet->title,
				'description' => $return->snippet->description,
				'thumbnailUrl'=> $return->snippet->thumbnails->default->url,
				'uploadDate'  => $return->snippet->publishedAt,
				'duration'    => $return->contentDetails->duration,
				'contentUrl'  => 'https://www.youtube.com/watch?v=' . $return->id,
			);
			echo '<script type="application/ld+json">' . json_encode( $request[$return->id] ) . '</script>';
		}
	}
endif;
add_action( 'wp_footer', 'hyc_youtube_post' );

<?php
  $api_url = 'https://www.googleapis.com/youtube/v3/videos?id=' . implode( ',', array_unique( $ids ) ) 
      . '&part=contentDetails,snippet&key={{YOUR GOOGLE API KEY}}';

{
    "@context": "http://schema.org", //固定值
    "@type": "VideoObject", //固定值
    "name": "炸肉排的故事", 
    "description": "如何在一小時內做出美味的炸肉排",
    "thumbnailUrl": "https://example.com/imgs/schnitzel-small.jpg",
    "uploadDate": "2015-02-05T08:00:00+08:00",
    "duration": "PT1M33S",
    "contentUrl": "https://streamserver.example.com/schnitzel.mp4"
  }