tag_escape( string $tag_name ): string
- Since
- 2.5.0, 6.5.5
- Source
wp-includes/formatting.php:4818
Compatibility
- WordPress
- since 6.5.5
- 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
$tag_namestring
Return value
string
Performance profile
How much work a call to tag_escape() 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
- Trivial
- Scaling
- Constant
- Instructions
- 13
- Plugin surface
- 1 hook
- Called by
- 3
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5. The body compiles to 13.
Third-party callbacks on 'tag_escape' run inside this call, and their cost is not bounded by anything here.
3 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()called directly
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost tag_escape() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 13 | strtolower(), apply_filters() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 13 | 13 | 0 | |
| 8.5 | 13 | 13 | 0 | |
| 8.4 | 13 | 13 | 0 | 3 fewer instructions than PHP 8.3 |
| 8.3 | 16 | 16 | 0 | |
| 8.2 | 16 | 16 | 0 | |
| 8.1 | 16 | 16 | 0 | |
| 7.4 | 16 | 16 | 0 |
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.
Hooks and filters fired · 1
One hook fires while tag_escape() runs, in this order:
- apply_filters( tag_escape )filterline 4828 (+10 into the body)
Filters a string cleaned and escaped for output as an HTML tag.
Uses · 1
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 3
- gallery_shortcode()Builds the Gallery shortcode output.
- get_tag_regex()Returns RegEx body to liberally match an opening HTML tag.
- render_block_core_template_part()Renders the `core/template-part` block on the server.
Source code
function tag_escape( $tag_name ) { $safe_tag = strtolower( preg_replace( '/[^a-zA-Z0-9-_:]/', '', $tag_name ) ); /** * Filters a string cleaned and escaped for output as an HTML tag. * * @since 2.8.0 * * @param string $safe_tag The tag name after it has been escaped. * @param string $tag_name The text before it was escaped. */ return apply_filters( 'tag_escape', $safe_tag, $tag_name );}Changelog
Introduced in 2.5.0. 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 6.9.7 tag, from
src/wp-includes/formatting.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.