twenty_twenty_one_print_first_instance_of_block( string $block_name, string|null $content = null, int $instances = 1 ): bool

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$block_namestring

The full block type name, or a partial match.
Example: core/image, core-embed/*.

$contentstring|nulloptional

The content to search in. Use null for get_the_content().Default: null

$instancesintoptional

How many instances of the block will be printed (max). Default 1.Default: 1

Return value

bool

Returns true if a block was located & printed, otherwise false.

Performance profile

How much work a call to twenty_twenty_one_print_first_instance_of_block() 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

14–45

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 49.

Plugin surface

1 hook

Third-party callbacks on 'the_content' run inside this call, and their cost is not bounded by anything here.

Called by

0

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

What it touches

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

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

What one call costs · 12 distinct outcomes

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

Hooks and filters fired · 1

One hook fires while twenty_twenty_one_print_first_instance_of_block() runs, in this order:

1. 1
   apply_filters( the_content )filterline 413 (+45 into the body)

   Filters the post content.

Uses · 4

• get_the_content()Retrieves the post content.
• parse_blocks()Parses blocks out of a content string.
• render_block()Renders a single block into a HTML string.
• apply_filters()Calls the callback functions that have been added to a filter hook.

Source code

View on Trac ↗View on GitHub ↗

368function twenty_twenty_one_print_first_instance_of_block( $block_name, $content = null, $instances = 1 ) {369	$instances_count = 0;370	$blocks_content  = '';371 372	if ( ! $content ) {373		$content = get_the_content();374	}375 376	// Parse blocks in the content.377	$blocks = parse_blocks( $content );378 379	// Loop blocks.380	foreach ( $blocks as $block ) {381 382		// Confidence check.383		if ( ! isset( $block['blockName'] ) ) {384			continue;385		}386 387		// Check if this the block matches the $block_name.388		$is_matching_block = false;389 390		// If the block ends with *, try to match the first portion.391		if ( '*' === $block_name[-1] ) {392			$is_matching_block = 0 === strpos( $block['blockName'], rtrim( $block_name, '*' ) );393		} else {394			$is_matching_block = $block_name === $block['blockName'];395		}396 397		if ( $is_matching_block ) {398			// Increment count.399			++$instances_count;400 401			// Add the block HTML.402			$blocks_content .= render_block( $block );403 404			// Break the loop if the $instances count was reached.405			if ( $instances_count >= $instances ) {406				break;407			}408		}409	}410 411	if ( $blocks_content ) {412		/** This filter is documented in wp-includes/post-template.php */413		echo apply_filters( 'the_content', $blocks_content );414		return true;415	}416 417	return false;418}

Changelog

Introduced in Twenty Twenty-One 1.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

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

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-content/themes/twentytwentyone/inc/template-functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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