WordPress: Post thumbnail

wp-post-thumbnail.php

/*-----------------------------------------------------------------------*/
/*	Display different types of post thumbnails
/*  USE: 
/*  Include this code in your functions.php file
/*  Include this function inside the loop:  nitro_post_thumbnail()
/*  Options:
/*  nitro_post_thumbnail(true)   -  include links to post for images
/*-----------------------------------------------------------------------*/
if( !function_exists( 'nitro_post_thumbnail' ) ):
function nitro_post_thumbnail( $link = false ){

	if( post_password_required() || is_attachment() ) return;

	global $post;


	// Get video thumbnail if is video post format
	$content = apply_filters( 'the_content', $post->post_content );
	$embeds = wp_extract_urls( $post->post_content );
	$video_thumbnail = false;
	
	// ICONS
	$icon = '';
	if( 'video' == get_post_format() ) $icon = 'play-circle';
	if( 'quote' == get_post_format() ) $icon = 'quote-left';
	if( 'audio' == get_post_format() ) $icon = 'headphones';


	foreach( $embeds as $embed ){
		if( strpos($embed, 'youtube') || strpos($embed, 'vimeo') ){

			if( strpos($embed, 'vimeo') ){
				$id = substr(parse_url($embed, PHP_URL_PATH), 1);
				$data = file_get_contents("http://vimeo.com/api/v2/video/$id.json");
				$data = json_decode($data);
				$video_thumbnail = $data[0]->thumbnail_large;
			}

			if( strpos($embed, 'youtube') ){
				preg_match('%(?:youtube(?:-nocookie)?\.com/(?:[^/]+/.+/|(?:v|e(?:mbed)?)/|.*[?&]v=)|youtu\.be/)([^"&?/ ]{11})%i', $embed, $match);
				$id = $match[1];
				$video_thumbnail = "https://img.youtube.com/vi/$id/maxresdefault.jpg";
			}
		
		}else{
			$video_thumbnail = $embed;
			$video_html = true;
		}
	}



	// Set $link as true for display an image link
	if( !$link ): 

		if( has_post_thumbnail() ):
			echo '<figure class="post-thumbnail">';
			the_post_thumbnail( 'post-thumbnail', array(
				'alt' => the_title_attribute( array(
					'echo' => false,
				) ),
			) );
			echo '</figure>';
		endif;

	else : ?>

		<?php if( has_post_thumbnail() || get_post_format() ): ?>
			<a class="post-thumbnail" href="<?php the_permalink(); ?>" aria-hidden="true">
				<?php if( has_post_thumbnail() ): 
					the_post_thumbnail( 'post-thumbnail', array(
						'alt' => the_title_attribute( array(
							'echo' => false,
						) ),
					) );
				else:
					if( $video_thumbnail ): 
						if( $video_html ): 
							echo do_shortcode('[video src="'.$video_thumbnail.'"]');
						else: ?>
							<img src="<?php echo esc_attr($video_thumbnail); ?>">
						<?php endif; 
					endif;
				endif; ?>

				<?php if(get_post_format()): ?><span class="fa fa-<?php echo $icon; ?>"></span><?php endif; ?>
			</a>
		<?php endif; ?>

	<?php endif;



}
endif;