has_block( string $block_name, int|string|WP_Post|null $post = null ): bool
- Since
- 5.0.0
- Source
wp-includes/blocks.php:909
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.
Compatibility
- WordPress
- since 5.0.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
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- Full block type to look for.
$postint|string|WP_Post|nulloptional- Post content, post ID, or post object.
Defaults to global $post.Default:null
Return value
bool- Whether the post content contains the specified block.
Performance profile
How much work a call to has_block() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Constant
- Instructions
- 7–34
- Plugin surface
- None
- Called by
- 4
Reaches the database via get_post().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 35.
Nothing here hands control to plugin code.
4 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- querycontent query
get_post()called directly
Further down the call graph this can also reach hook, option, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 4 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost has_block() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 7–17 | has_blocks() |
has_blocks() && is_string($post) && !$post | 21–26 | has_blocks(), strip_core_block_namespace() |
has_blocks() && !is_string($post) && $post | 21–25 | has_blocks(), get_post() |
has_blocks() && !is_string($post) && !$post | 27–34 | has_blocks(), get_post(), strip_core_block_namespace() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 35 | 7–34 | 6 | |
| 8.5 | 35 | 7–34 | 6 | |
| 8.4 | 35 | 7–34 | 6 | 9 fewer instructions than PHP 8.3 |
| 8.3 | 44 | 7–43 | 6 | |
| 8.2 | 44 | 7–43 | 6 | |
| 8.1 | 44 | 7–43 | 6 | 2 fewer instructions than PHP 7.4 |
| 7.4 | 46 | 7–45 | 6 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 4
- has_blocks()Determines whether a post or content string has blocks.
- get_post()Retrieves post data given a post ID or post object.
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
- strip_core_block_namespace()Returns the block name to use for serialization. This will remove the default "core/" namespace from a block name.
Used by · 4
- apply_block_hooks_to_content()Runs the hooked blocks algorithm on the given content.
- get_post_galleries()Retrieves galleries from the passed post's content.
- get_the_content()Retrieves the post content.
- render_block_core_post_content()Renders the `core/post-content` block on the server.
Source code
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;}Changelog
Introduced in 5.0.0. Unchanged from 6.7.7 through 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-includes/blocks.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.