Using WordPress ‘has_block()’ PHP function

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The has_block() WordPress PHP function determines if a post or a string contains a specific block type.

Usage

Here’s a simple example of how to use this function:

if ( has_block( 'core/gallery' ) ) {
    echo 'This post contains a gallery block.';
} else {
    echo 'This post does not contain a gallery block.';
}

In this case, if the post contains a ‘core/gallery’ block, the function will return true, and the message ‘This post contains a gallery block.’ will be displayed. Otherwise, it will return false, and ‘This post does not contain a gallery block.’ will be displayed.

Parameters

  • $block_name (string): The full block type you are looking for. For example, ‘core/gallery’.
  • $post (_int|string|WPPost|null): The post content, post ID, or post object. This is optional and defaults to the global $post variable. If not provided, the function uses the content of the current post.

More information

See WordPress Developer Resources: has_block()

This function does not work in reusable blocks. If you need to check blocks within a reusable block, you need to parse content first. It also does not support arrays, so if you need to check for multiple blocks, use || (or) operator between your checks.

Examples

Checking if a post contains a specific block

if ( has_block( 'core/paragraph' ) ) {
    echo 'This post contains a paragraph block.';
}

This will display ‘This post contains a paragraph block.’ if the post has a ‘core/paragraph’ block.

Checking a specific post for a block

if ( has_block( 'core/paragraph', 42 ) ) {
    echo 'Post 42 contains a paragraph block.';
}

This will check if post 42 contains a ‘core/paragraph’ block.

Checking for multiple blocks

if ( has_block( 'core/paragraph' ) || has_block( 'core/gallery' ) ) {
    echo 'This post contains either a paragraph or a gallery block.';
}

This will check if the post contains either a ‘core/paragraph’ block or a ‘core/gallery’ block.

Checking for a custom block

if ( has_block( 'my-namespace/my-custom-block' ) ) {
    echo 'This post contains my custom block.';
}

This checks if the post contains a custom block defined as ‘my-namespace/my-custom-block’.

Checking a string for a block

$content = '...'; // Some string content
if ( has_block( 'core/paragraph', $content ) ) {
    echo 'The provided content contains a paragraph block.';
}

This checks the provided string $content for a ‘core/paragraph’ block.