render_block_core_post_featured_image( array $attributes, string $content, WP_Block $block ): string

Compatibility

Present in every tracked release (6.7.10 to 7.1.3), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$attributesarray

Block attributes.

$contentstring

Block default content.

$blockWP_Block

Block instance.

Return value

string

Returns the featured image for the current post.

Performance profile

How much work a call to render_block_core_post_featured_image() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via get_post().

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

46–188

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 253.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

• querycontent queryget_post()called directly
• hookthird-party callbacksapply_filters()one call below render_block_core_post_featured_image()

Further down the call graph this can also reach option, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 246 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost render_block_core_post_featured_image() can have, taken from its control-flow graph on PHP 8.5.

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Uses · 12

• get_block_core_post_featured_image_border_attributes()Generates class names and styles to apply the border support styles for the Post Featured Image block.
• get_block_core_post_featured_image_overlay_element_markup()Generate markup for the HTML element that will be used for the overlay.
• get_the_title()Retrieves the post title.
• __()Retrieves the translation of $text.
• wp_style_engine_get_styles()Global public interface method to generate styles from a single style object, e.g. the value of a block's attributes.style object or the top level styles in theme.json.
• get_the_post_thumbnail()Retrieves the post thumbnail.
• get_post()Retrieves post data given a post ID or post object.
• esc_attr()Escaping for HTML attributes.
• safecss_filter_attr()Filters an inline style attribute and removes disallowed rules.
• get_the_permalink()Retrieves the full permalink for the current post or post ID.
• get_block_wrapper_attributes()Generates a string of attributes by applying to the current block being rendered all of the features that the block supports.
• WP_HTML_Tag_Processor::__construct()Constructor.

Source code

View on Trac ↗View on GitHub ↗

18function render_block_core_post_featured_image( $attributes, $content, $block ) {19	if ( ! isset( $block->context['postId'] ) ) {20		return '';21	}22	$post_ID = $block->context['postId'];23 24	$is_link        = isset( $attributes['isLink'] ) && $attributes['isLink'];25	$size_slug      = isset( $attributes['sizeSlug'] ) ? $attributes['sizeSlug'] : 'post-thumbnail';26	$attr           = get_block_core_post_featured_image_border_attributes( $attributes );27	$overlay_markup = get_block_core_post_featured_image_overlay_element_markup( $attributes );28 29	if ( $is_link ) {30		if ( get_the_title( $post_ID ) ) {31			$attr['alt'] = trim( strip_tags( get_the_title( $post_ID ) ) );32		} else {33			$attr['alt'] = sprintf(34				// translators: %d is the post ID.35				__( 'Untitled post %d' ),36				$post_ID37			);38		}39	}40 41	$extra_styles = '';42 43	// Aspect ratio with a height set needs to override the default width/height.44	if ( ! empty( $attributes['aspectRatio'] ) ) {45		$extra_styles .= 'width:100%;height:100%;';46	} elseif ( ! empty( $attributes['height'] ) ) {47		$extra_styles .= "height:{$attributes['height']};";48	}49 50	if ( ! empty( $attributes['scale'] ) ) {51		$extra_styles .= "object-fit:{$attributes['scale']};";52	}53	if ( ! empty( $attributes['style']['shadow'] ) ) {54		$shadow_styles = wp_style_engine_get_styles( array( 'shadow' => $attributes['style']['shadow'] ) );55 56		if ( ! empty( $shadow_styles['css'] ) ) {57			$extra_styles .= $shadow_styles['css'];58		}59	}60 61	if ( ! empty( $extra_styles ) ) {62		$attr['style'] = empty( $attr['style'] ) ? $extra_styles : $attr['style'] . $extra_styles;63	}64 65	$featured_image = get_the_post_thumbnail( $post_ID, $size_slug, $attr );66 67	// Get the first image from the post.68	if ( $attributes['useFirstImageFromPost'] && ! $featured_image ) {69		$content_post = get_post( $post_ID );70		$content      = $content_post->post_content;71		$processor    = new WP_HTML_Tag_Processor( $content );72 73		/*74		 * Transfer the image tag from the post into a new text snippet.75		 * Because the HTML API doesn't currently expose a way to extract76		 * HTML substrings this is necessary as a workaround. Of note, this77		 * is different than directly extracting the IMG tag:78		 * - If there are duplicate attributes in the source there will only be one in the output.79		 * - If there are single-quoted or unquoted attributes they will be double-quoted in the output.80		 * - If there are named character references in the attribute values they may be replaced with their direct code points. E.g. `&hellip;` becomes `…`.81		 * In the future there will likely be a mechanism to copy snippets of HTML from82		 * one document into another, via the HTML Processor's `get_outer_html()` or83		 * equivalent. When that happens it would be appropriate to replace this custom84		 * code with that canonical code.85		 */86		if ( $processor->next_tag( 'img' ) ) {87			$tag_html = new WP_HTML_Tag_Processor( '<img>' );88			$tag_html->next_tag();89			foreach ( $processor->get_attribute_names_with_prefix( '' ) as $name ) {90				$tag_html->set_attribute( $name, $processor->get_attribute( $name ) );91			}92			$featured_image = $tag_html->get_updated_html();93		}94	}95 96	if ( ! $featured_image ) {97		return '';

Changelog

Introduced in 5.8.0. Unchanged from 6.7.10 through 7.1.3.

1. 6.7.10
2. 6.8.11
3. 6.9.10
4. 7.0.7
5. 7.1.3

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.8.11 tag, from src/wp-includes/blocks/post-featured-image.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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