Title: pre_render_block
Published: February 22, 2019
Last modified: August 20, 2026

---

# apply_filters( ‘pre_render_block’, string|null $pre_render, array $parsed_block, WP_Block|null $parent_block )

## In this article

 * [Parameters](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#changelog)

Allows [render_block()](https://developer.wordpress.org/reference/functions/render_block/)
to be short-circuited, by returning a non-null value.

## 󠀁[Parameters](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#parameters)󠁿

 `$pre_render`string|null

The pre-rendered content. Default null.

`$parsed_block`array

An associative array of the block being rendered. See [WP_Block_Parser_Block](https://developer.wordpress.org/reference/classes/wp_block_parser_block/).

 * `blockName` string|null
 * Name of block.
 * `attrs` array
 * Attributes from block comment delimiters.
 * `innerBlocks` array[]
 * List of inner blocks. An array of arrays that have the same structure as this
   one.
 * `innerHTML` string
 * HTML from inside block comment delimiters.
 * `innerContent` array
 * List of string fragments and null markers where inner blocks were found.

`$parent_block`[WP_Block](https://developer.wordpress.org/reference/classes/wp_block/)
|null

If this is a nested block, a reference to the parent block.

## 󠀁[Source](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#source)󠁿

    ```php
    $pre_render = apply_filters( 'pre_render_block', null, $parsed_block, $parent_block );
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/blocks.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.1/src/wp-includes/blocks.php#L2436)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/blocks.php#L2436-L2436)

## 󠀁[Related](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#related)󠁿

| Used by | Description | 
| [WP_Block::render()](https://developer.wordpress.org/reference/classes/wp_block/render/)`wp-includes/class-wp-block.php` |

Generates the render output for the block.

  | 
| [render_block()](https://developer.wordpress.org/reference/functions/render_block/)`wp-includes/blocks.php` |

Renders a single block into a HTML string.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/hooks/pre_render_block/?utm_source=www.bubuku.com&output_format=md#changelog)󠁿

| Version | Description | 
| [5.9.0](https://developer.wordpress.org/reference/since/5.9.0/) | The `$parent_block` parameter was added. | 
| [5.1.0](https://developer.wordpress.org/reference/since/5.1.0/) | Introduced. |

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