wp_kses_hair( string $attr, string[] $allowed_protocols ): array[]
- Since
- 1.0.0
- Source
wp-includes/kses.php:1391
Description
This function does a lot of work. It parses an attribute list into an array with attribute data, and tries to do the right thing even if it gets weird input. It will add quotes around attribute values that don't have any quotes or apostrophes around them, to make it easier to produce HTML code that will conform to W3C's HTML specification. It will also remove bad URL protocols from attribute values. It also reduces duplicate attributes by using the attribute defined first (foo='bar' foo='baz' will result in foo='bar').
Compatibility
- WordPress
- since 1.0.0
- 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
$attrstring- Attribute list from HTML element to closing HTML element tag.
$allowed_protocolsstring[]- Array of allowed URL protocols.
Return value
array[]- Array of attribute information after parsing.
Performance profile
How much work a call to wp_kses_hair() 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
- 15–24
- Plugin surface
- None
- Called by
- 4
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 191.
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
- hookthird-party callbacks
apply_filters()one call below wp_kses_hair()
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 wp_kses_hair() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 15–24 | wp_kses_uri_attributes() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 191 | 15–24 | 20 | |
| 8.5 | 191 | 15–24 | 20 | |
| 8.4 | 191 | 15–24 | 20 | 33 fewer instructions than PHP 8.3 |
| 8.3 | 224 | 15–24 | 20 | |
| 8.2 | 224 | 15–24 | 20 | 1 more instruction than PHP 8.1 |
| 8.1 | 223 | 15–24 | 20 | |
| 7.4 | 223 | 15–24 | 20 |
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 · 3
- wp_kses_uri_attributes()Returns an array of HTML attribute names whose value contains a URL.
- wp_kses_bad_protocol()Sanitizes a string and removed disallowed URL protocols.
- wp_kses_html_error()Handles parsing errors in `wp_kses_hair()`.
Used by · 4
- wp_filter_oembed_iframe_title_attribute()Filters the given oEmbed HTML to make sure iframes have a title attribute.
- wp_kses_attr()Removes all attributes, if none are allowed for this element.
- wp_rel_callback()Callback to add a rel attribute to HTML A element.
- wp_targeted_link_rel_callback()Callback to add `rel="noopener"` string to HTML A element.
Source code
function wp_kses_hair( $attr, $allowed_protocols ) { $attrarr = array(); $mode = 0; $attrname = ''; $uris = wp_kses_uri_attributes(); // Loop through the whole attribute list. while ( strlen( $attr ) !== 0 ) { $working = 0; // Was the last operation successful? switch ( $mode ) { case 0: if ( preg_match( '/^([_a-zA-Z][-_a-zA-Z0-9:.]*)/', $attr, $match ) ) { $attrname = $match[1]; $working = 1; $mode = 1; $attr = preg_replace( '/^[_a-zA-Z][-_a-zA-Z0-9:.]*/', '', $attr ); } break; case 1: if ( preg_match( '/^\s*=\s*/', $attr ) ) { // Equals sign. $working = 1; $mode = 2; $attr = preg_replace( '/^\s*=\s*/', '', $attr ); break; } if ( preg_match( '/^\s+/', $attr ) ) { // Valueless. $working = 1; $mode = 0; if ( false === array_key_exists( $attrname, $attrarr ) ) { $attrarr[ $attrname ] = array( 'name' => $attrname, 'value' => '', 'whole' => $attrname, 'vless' => 'y', ); } $attr = preg_replace( '/^\s+/', '', $attr ); } break; case 2: if ( preg_match( '%^"([^"]*)"(\s+|/?$)%', $attr, $match ) ) { // "value" $thisval = $match[1]; if ( in_array( strtolower( $attrname ), $uris, true ) ) { $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); } if ( false === array_key_exists( $attrname, $attrarr ) ) { $attrarr[ $attrname ] = array( 'name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n', ); } $working = 1; $mode = 0; $attr = preg_replace( '/^"[^"]*"(\s+|$)/', '', $attr ); break; } if ( preg_match( "%^'([^']*)'(\s+|/?$)%", $attr, $match ) ) { // 'value' $thisval = $match[1]; if ( in_array( strtolower( $attrname ), $uris, true ) ) { $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); } if ( false === array_key_exists( $attrname, $attrarr ) ) { $attrarr[ $attrname ] = array(Changelog
Introduced in 1.0.0. One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
array[] to array<string,.verified against sourceAbout this page
- Parsed data
- Generated from the wordpress-develop 6.7.7 tag, from
src/wp-includes/kses.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.