WP_Theme_JSON::flatten_tree() WordPress Method
The WP_Theme_JSON::flatten_tree() method is used to flatten an array of theme objects into a single array. This is useful for creating a list of all available themes, or for creating a list of themes that are compatible with a specific plugin or theme.
WP_Theme_JSON::flatten_tree( array $tree, string $prefix = '', string $token = '--' ) #
Given a tree, it creates a flattened one by merging the keys and binding the leaf values to the new keys.
Description
It also transforms camelCase names into kebab-case and substitutes ‘/’ by ‘-‘.
This is thought to be useful to generate CSS Custom Properties from a tree, although there’s nothing in the implementation of this function that requires that format.
For example, assuming the given prefix is ‘–wp’ and the token is ‘–‘, for this input tree:
{
'some/property': 'value',
'nestedProperty': {
'sub-property': 'value'
}
}it’ll return this output:
{
'--wp--some-property': 'value',
'--wp--nested-property--sub-property': 'value'
}Parameters
- $tree
(array)(Required)Input tree to process.
- $prefix
(string)(Optional) Prefix to prepend to each variable.
Default value: ''
- $token
(string)(Optional) Token to use between levels.
Default value: '--'
Return
(array) The flattened tree.
Source
File: wp-includes/class-wp-theme-json.php
protected static function flatten_tree( $tree, $prefix = '', $token = '--' ) {
$result = array();
foreach ( $tree as $property => $value ) {
$new_key = $prefix . str_replace(
'/',
'-',
strtolower( _wp_to_kebab_case( $property ) )
);
if ( is_array( $value ) ) {
$new_prefix = $new_key . $token;
$result = array_merge(
$result,
static::flatten_tree( $value, $new_prefix, $token )
);
} else {
$result[ $new_key ] = $value;
}
}
return $result;
}
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Changelog
| Version | Description |
|---|---|
| 5.8.0 | Introduced. |