wp_kses_attr_check

Determine whether an attribute is allowed.

Description

wp_kses_attr_check( (string) &$name, (string) &$value, (string) &$whole, (string) $vless, (string) $element, (array) $allowed_html );

Parameters (6)

0. $name (string) => &$name: The attribute name. Returns empty string when not allowed.
1. $value (string) => &$value: The attribute value. Returns a filtered value.
2. $whole (string) => &$whole: The name=value input. Returns filtered input.
3. $vless (string): 'y' when attribute like enabled,, otherwise n..
4. $element (string): The name of the element to which this attribute belongs.
5. $allowed_html (array): The full list of allowed elements and attributes.

Usage

if ( !function_exists( 'wp_kses_attr_check' ) ) { 
    require_once ABSPATH . WPINC . '/kses.php'; 
} 
  
// The attribute name. Returns empty string when not allowed. 
$name = &$name; 
  
// The attribute value. Returns a filtered value. 
$value = &$value; 
  
// The name=value input. Returns filtered input. 
$whole = &$whole; 
  
// 'y' when attribute like "enabled", otherwise 'n'. 
$vless = ''; 
  
// The name of the element to which this attribute belongs. 
$element = ''; 
  
// The full list of allowed elements and attributes. 
$allowed_html = array(); 
  
// NOTICE! Understand what this does before running. 
$result = wp_kses_attr_check($name, $value, $whole, $vless, $element, $allowed_html);

Defined (1)

The function is defined in the following location(s).

/wp-includes/kses.php

function wp_kses_attr_check( &$name, &$value, &$whole, $vless, $element, $allowed_html ) { 
    $allowed_attr = $allowed_html[strtolower( $element )]; 
 
    $name_low = strtolower( $name ); 
    if ( ! isset( $allowed_attr[$name_low] ) || '' == $allowed_attr[$name_low] ) { 
        $name = $value = $whole = ''; 
        return false; 
    } 
 
    if ( 'style' == $name_low ) { 
        $new_value = safecss_filter_attr( $value ); 
 
        if ( empty( $new_value ) ) { 
            $name = $value = $whole = ''; 
            return false; 
        } 
 
        $whole = str_replace( $value, $new_value, $whole ); 
        $value = $new_value; 
    } 
 
    if ( is_array( $allowed_attr[$name_low] ) ) { 
        // there are some checks 
        foreach ( $allowed_attr[$name_low] as $currkey => $currval ) { 
            if ( ! wp_kses_check_attr_val( $value, $vless, $currkey, $currval ) ) { 
                $name = $value = $whole = ''; 
                return false; 
            } 
        } 
    } 
 
    return true; 
}