Efficient Script Loading for oEmbeds

efficient-fitvids.php

/**
 * Enqueue theme scripts
 */
function prefix_scripts() {

		// FitVids Script conditionally enqueued from inc/extras.php
		wp_register_script(
			'prefix-fitvids',
			get_template_directory_uri() . '/js/jquery.fitvids.min.js',
			array( 'jquery' ),
			'1.0.0',
			true
		);

}
add_action( 'wp_enqueue_scripts', 'prefix_scripts' );

/**
 * Enqueues FitVids, since the embed might be a video.
 *
 * @since 1.0.0.
 *
 * @param  string    $html    The generated HTML of the embed handler.
 * @param  string    $url     The embed URL.
 * @param  array     $attr    The attributes of the embed shortcode.
 *
 * @return string             Returned HTML.
 */
function prefix_embed_container( $html, $url, $attr ) {
	// Bail if this is the admin
	if ( is_admin() ) {
		return $html;
	}

	if ( isset( $attr['width'] ) ) {
		wp_enqueue_script( 'prefix-fitvids' );
	}

	return $html;
}
add_filter( 'embed_handler_html', 'prefix_embed_container', 10, 3 );
add_filter( 'embed_oembed_html' , 'prefix_embed_container', 10, 3 );