filter_block_content( string $text, array[]|string $allowed_html = 'post', string[] $allowed_protocols = array() ): string
- Since
- 5.3.1
- Source
wp-includes/blocks.php:2121
Compatibility
- WordPress
- since 5.3.1
- 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
$textstring- Text that may contain block content.
$allowed_htmlarray[]|stringoptional- An array of allowed HTML elements and attributes, or a context name such as 'post'. See wp_kses_allowed_html() for the list of accepted context names. Default 'post'.Default:
'post' $allowed_protocolsstring[]optional- Array of allowed URL protocols.
Defaults to the result of wp_allowed_protocols().Default:array()
Return value
string- The filtered and sanitized content result.
Performance profile
How much work a call to filter_block_content() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Light
- Scaling
- Scales with input
- Instructions
- 13–22
- Plugin surface
- None
- Called by
- 1
Touches nothing outside its own arguments.
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 33.
Nothing here hands control to plugin code.
1 place in core call this, so the cost is paid more often than your own code shows.
What it touches
- regexregular expression over the whole input
preg_replace_callback()called directly - hookthird-party callbacks
apply_filters()one call below filter_block_content()
Further down the call graph this can also reach option, cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost filter_block_content() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!$text | 13–16 | parse_blocks() |
$text | 21–22 | preg_replace_callback(), parse_blocks() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 33 | 13–22 | 4 | |
| 8.5 | 33 | 13–22 | 4 | |
| 8.4 | 33 | 13–22 | 4 | 6 fewer instructions than PHP 8.3 |
| 8.3 | 39 | 16–28 | 4 | |
| 8.2 | 39 | 16–28 | 4 | |
| 8.1 | 39 | 16–28 | 4 | |
| 7.4 | 39 | 16–28 | 4 |
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
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
- parse_blocks()Parses blocks out of a content string.
- filter_block_kses()Filters and sanitizes a parsed block to remove non-allowable HTML from block attribute values.
- serialize_block()Returns the content of a block, including comment delimiters, serializing all attributes from the given parsed block.
Used by · 1
- wp_pre_kses_block_attributes()Removes non-allowable HTML from parsed block attribute values when filtering in the post context.
Source code
function filter_block_content( $text, $allowed_html = 'post', $allowed_protocols = array() ) { $result = ''; if ( str_contains( $text, '<!--' ) && str_contains( $text, '--->' ) ) { $text = preg_replace_callback( '%<!--(.*?)--->%', '_filter_block_content_callback', $text ); } $blocks = parse_blocks( $text ); foreach ( $blocks as $block ) { $block = filter_block_kses( $block, $allowed_html, $allowed_protocols ); $result .= serialize_block( $block ); } return $result;}Changelog
Introduced in 5.3.1. 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.