Source

File: wp-includes/media-template.php

function wp_underscore_video_template() {
	$video_types = wp_get_video_extensions();
	?>
<#  var w_rule = '', classes = [],
		w, h, settings = wp.media.view.settings,
		isYouTube = isVimeo = false;

	if ( ! _.isEmpty( data.model.src ) ) {
		isYouTube = data.model.src.match(/youtube|youtu\.be/);
		isVimeo = -1 !== data.model.src.indexOf('vimeo');
	}

	if ( settings.contentWidth && data.model.width >= settings.contentWidth ) {
		w = settings.contentWidth;
	} else {
		w = data.model.width;
	}

	if ( w !== data.model.width ) {
		h = Math.ceil( ( data.model.height * w ) / data.model.width );
	} else {
		h = data.model.height;
	}

	if ( w ) {
		w_rule = 'width: ' + w + 'px; ';
	}

	if ( isYouTube ) {
		classes.push( 'youtube-video' );
	}

	if ( isVimeo ) {
		classes.push( 'vimeo-video' );
	}

#>
<div style="{{ w_rule }}" class="wp-video">
<video controls
	class="wp-video-shortcode {{ classes.join( ' ' ) }}"
	<# if ( w ) { #>width="{{ w }}"<# } #>
	<# if ( h ) { #>height="{{ h }}"<# } #>
	<?php
	$props = array(
		'poster'  => '',
		'preload' => 'metadata',
	);
	foreach ( $props as $key => $value ) :
		if ( empty( $value ) ) {
			?>
		<#
		if ( ! _.isUndefined( data.model.<?php echo $key; ?> ) && data.model.<?php echo $key; ?> ) {
			#> <?php echo $key; ?>="{{ data.model.<?php echo $key; ?> }}"<#
		} #>
			<?php
		} else {
			echo $key
			?>
			="{{ _.isUndefined( data.model.<?php echo $key; ?> ) ? '<?php echo $value; ?>' : data.model.<?php echo $key; ?> }}"
			<?php
		}
	endforeach;
	?>
	<#
	<?php
	foreach ( array( 'autoplay', 'loop' ) as $attr ) :
		?>
	if ( ! _.isUndefined( data.model.<?php echo $attr; ?> ) && data.model.<?php echo $attr; ?> ) {
		#> <?php echo $attr; ?><#
	}
	<?php endforeach ?>#>
>
	<# if ( ! _.isEmpty( data.model.src ) ) {
		if ( isYouTube ) { #>
		<source src="{{ data.model.src }}" type="video/youtube" />
		<# } else if ( isVimeo ) { #>
		<source src="{{ data.model.src }}" type="video/vimeo" />
		<# } else { #>
		<source src="{{ data.model.src }}" type="{{ settings.embedMimes[ data.model.src.split('.').pop() ] }}" />
		<# }
	} #>

	<?php
	foreach ( $video_types as $type ) :
		?>
	<# if ( data.model.<?php echo $type; ?> ) { #>
	<source src="{{ data.model.<?php echo $type; ?> }}" type="{{ settings.embedMimes[ '<?php echo $type; ?>' ] }}" />
	<# } #>
	<?php endforeach; ?>
	{{{ data.model.content }}}
</video>
</div>
	<?php
}