has_block() – Function | Developer.WordPress.org

Determines whether a $post or a string contains a specific block type.

Description

This test optimizes for performance rather than strict accuracy, detecting whether the block type exists but not validating its structure and not checking synced patterns (formerly called reusable blocks). For strict accuracy, you should use the block parser on post content.

Parameters

$block_namestringrequired: Full block type to look for.
$postint|string|WP_Post|nulloptional: Post content, post ID, or post object.
Defaults to global $post.
Default:null

Return

bool Whether the post content contains the specified block.

Source

function has_block( $block_name, $post = null ) {
	if ( ! has_blocks( $post ) ) {
		return false;
	}

	if ( ! is_string( $post ) ) {
		$wp_post = get_post( $post );
		if ( $wp_post instanceof WP_Post ) {
			$post = $wp_post->post_content;
		}
	}

	/*
	 * Normalize block name to include namespace, if provided as non-namespaced.
	 * This matches behavior for WordPress 5.0.0 - 5.3.0 in matching blocks by
	 * their serialized names.
	 */
	if ( ! str_contains( $block_name, '/' ) ) {
		$block_name = 'core/' . $block_name;
	}

	// Test for existence of block by its fully qualified name.
	$has_block = str_contains( $post, '<!-- wp:' . $block_name . ' ' );

	if ( ! $has_block ) {
		/*
		 * If the given block name would serialize to a different name, test for
		 * existence by the serialized form.
		 */
		$serialized_block_name = strip_core_block_namespace( $block_name );
		if ( $serialized_block_name !== $block_name ) {
			$has_block = str_contains( $post, '<!-- wp:' . $serialized_block_name . ' ' );
		}
	}

	return $has_block;
}

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Uses	Description
strip_core_block_namespace()`wp-includes/blocks.php`	Returns the block name to use for serialization. This will remove the default “core/” namespace from a block name.
has_blocks()`wp-includes/blocks.php`	Determines whether a post or content string has blocks.
get_post()`wp-includes/post.php`	Retrieves post data given a post ID or post object.

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Used by	Description
get_the_content()`wp-includes/post-template.php`	Retrieves the post content.

Changelog

Version	Description
5.0.0	Introduced.

User Contributed Notes

Skip to note 7 content

Andrew Lima 4 years ago

You must log in to vote on the helpfulness of this noteVote results for this note: 3You must log in to vote on the helpfulness of this note
If you are wanting to check if a custom (non core block) is for a page or post, include the namespace/name-of-block:
```
if ( has_block( 'my-namespace/block-name' ) ) {
 // Do stuff here.
}
```
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Karolina Vyskocilova 3 years ago

The function doesn’t work in reusable blocks. If you need to check blocks within a reusable block you need to parse content first. Here is my simplified functional solution (although OOP would do bit better):

/**
 * Has block function which searches as well in reusable blocks.
 *
 * @param mixed $block_name Full Block type to look for.
 * @return bool
 */
function wpdocs_enhanced_has_block( $block_name ) {
	if ( has_block( $block_name ) ) {
		return true;
	}

	if ( has_block( 'core/block' ) ) {
		$content = get_post_field( 'post_content' );
		$blocks = parse_blocks( $content );
		return wpdocs_search_reusable_blocks_within_innerblocks( $blocks, $block_name );
	}

	return false;
}

/**
 * Search for the selected block within inner blocks.
 *
 * The helper function for wpdocs_enhanced_has_block() function.
 *
 * @param array $blocks Blocks to loop through.
 * @param string $block_name Full Block type to look for.
 * @return bool
 */
function wpdocs_search_reusable_blocks_within_innerblocks( $blocks, $block_name ) {
	foreach ( $blocks as $block ) {
		if ( isset( $block['innerBlocks'] ) && ! empty( $block['innerBlocks'] ) ) {
			wpdocs_search_reusable_blocks_within_innerblocks( $block['innerBlocks'], $block_name );
		} elseif ( 'core/block' === $block['blockName'] && ! empty( $block['attrs']['ref'] ) && has_block( $block_name, $block['attrs']['ref'] ) ) {
			return true;
		}
	}

	return false;
}

Now you can call wpdocs_enhanced_has_block( 'core/heading' ) to check for heading block both in post content and if not found in all reusable blocks within the post.

Skip to note 9 content

Tom Napier 5 years ago

You must log in to vote on the helpfulness of this noteVote results for this note: 1You must log in to vote on the helpfulness of this note
```
// Note: does not support arrays
if ( has_block( array( 'gallery', 'button' ) ) ) {
	// error
}

// Use || instead
if ( has_block( 'gallery' ) || has_block( 'button' ) ) {
	// Do something.
} 
```
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John Antonacci 4 years ago

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If adding a “number” value for $post make sure it’s an integer (if a string – like ‘5’) sneaks in you will get a return of false.

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wpdevlol 1 year ago

You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note
I just want to know if Gutenberg block exist to create the logic, i have a hybrid kind of site, previous answers only had specific blocks with has_block, didnt suit me so i found this.
```
// Check if any Gutenberg block exists
if ( function_exists( 'register_block_type' ) && has_blocks() ) {
	// Do stuff
	echo 'At least one Gutenberg block exists!';
} else {
	// Do stuff
	echo 'No Gutenberg blocks found.';
}
```
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Nilambar Sharma 5 years ago

You must log in to vote on the helpfulness of this noteVote results for this note: -3You must log in to vote on the helpfulness of this note
```
if ( has_block( 'gallery' ) ) {
    // Do something.
}
```
- Blocks will always have a namespace followed by / before the name. So, this example should be:
  
  if ( has_block( 'core/gallery' ) ) { // Do something. }
  
  or
  
  if ( has_block( 'my-custom-block/gallery' ) ) { // Do something. }
  
  Pea Lutz 3 years ago
- Unlike reusable blocks core/block, it returns true for the Group block core/group. i.e. if you select multiple blocks and group them together, the has_block() will return true for a check against a block inside the group.
  
  desertsailors 2 years ago
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has_block( string $block_name, int|string|WP_Post|null $post = null ): bool

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