1<?php
  2/**
  3 * Server-side rendering of the `core/video` block.
  4 *
  5 * @package WordPress
  6 */
  7
  8/**
  9 * Renders the `core/video` block on the server to supply the width and height attributes from the attachment metadata.
 10 *
 11 * @since 6.9.0
 12 *
 13 * @phpstan-param  array{ "id"?: positive-int } $attributes
 14 *
 15 * @param array   $attributes The block attributes.
 16 * @param string  $content    The block content.
 17 * @return string The block content with the dimensions added.
 18 */
 19function render_block_core_video( array $attributes, string $content ): string {
 20	// if the content lacks any video tag, abort.
 21	if ( ! str_contains( $content, '<video' ) ) {
 22		return $content;
 23	}
 24
 25	// If the 'id' attribute is not populated for a video attachment, abort.
 26	if (
 27		! isset( $attributes['id'] ) ||
 28		! is_int( $attributes['id'] ) ||
 29		$attributes['id'] <= 0
 30	) {
 31		return $content;
 32	}
 33
 34	// If the 'id' attribute wasn't for an attachment, abort.
 35	if ( get_post_type( $attributes['id'] ) !== 'attachment' ) {
 36		return $content;
 37	}
 38
 39	// Get the width and height metadata for the video, and abort if absent or invalid.
 40	$metadata = wp_get_attachment_metadata( $attributes['id'] );
 41	if (
 42		! isset( $metadata['width'], $metadata['height'] ) ||
 43		! ( is_int( $metadata['width'] ) && is_int( $metadata['height'] ) ) ||
 44		! ( $metadata['width'] > 0 && $metadata['height'] > 0 )
 45	) {
 46		return $content;
 47	}
 48
 49	// Locate the VIDEO tag to add the dimensions.
 50	$p = new WP_HTML_Tag_Processor( $content );
 51	if ( ! $p->next_tag( array( 'tag_name' => 'VIDEO' ) ) ) {
 52		return $content;
 53	}
 54
 55	$p->set_attribute( 'width', (string) $metadata['width'] );
 56	$p->set_attribute( 'height', (string) $metadata['height'] );
 57
 58	/*
 59	 * The aspect-ratio style is needed due to an issue with the CSS spec: <https://github.com/w3c/csswg-drafts/issues/7524>.
 60	 * Note that a style rule using attr() like the following cannot currently be used:
 61	 *
 62	 *     .wp-block-video video[width][height] {
 63	 *         aspect-ratio: attr(width type(<number>)) / attr(height type(<number>));
 64	 *     }
 65	 *
 66	 * This is because this attr() is yet only implemented in Chromium: <https://caniuse.com/css3-attr>.
 67	 */
 68	$style = $p->get_attribute( 'style' );
 69	if ( ! is_string( $style ) ) {
 70		$style = '';
 71	}
 72	$aspect_ratio_style = sprintf( 'aspect-ratio: %d / %d;', $metadata['width'], $metadata['height'] );
 73	$p->set_attribute( 'style', $aspect_ratio_style . $style );
 74
 75	return $p->get_updated_html();
 76}
 77
 78/**
 79 * Registers the `core/video` block on server.
 80 *
 81 * @since 6.9.0
 82 */
 83function register_block_core_video(): void {
 84	register_block_type_from_metadata(
 85		__DIR__ . '/video',
 86		array(
 87			'render_callback' => 'render_block_core_video',
 88		)
 89	);
 90}
 91add_action( 'init', 'register_block_core_video' );
 92