public function ThemeManager::alter in Drupal 9

Same name and namespace in other branches

8 core/lib/Drupal/Core/Theme/ThemeManager.php \Drupal\Core\Theme\ThemeManager::alter()

Passes alterable variables to specific $theme_TYPE_alter() implementations.

Executes an alter hook on the current theme. It also invokes alter hooks for all base themes.

$theme specifies the theme name of the active theme and all its base themes.

This dispatch function hands off the passed-in variables to type-specific $theme_TYPE_alter() implementations in the active theme. It ensures a consistent interface for all altering operations.

A maximum of 2 alterable arguments is supported. In case more arguments need to be passed and alterable, modules provide additional variables assigned by reference in the last $context argument:

$context = array(
  'alterable' => &$alterable,
  'unalterable' => $unalterable,
  'foo' => 'bar',
);
$this
  ->alter('mymodule_data', $alterable1, $alterable2, $context);

Note that objects are always passed by reference. If it is absolutely required that no implementation alters a passed object in $context, then an object needs to be cloned:

$context = array(
  'unalterable_object' => clone $object,
);
$this
  ->alter('mymodule_data', $data, $context);

Parameters

string|array $type: A string describing the type of the alterable $data. 'form', 'links', 'node_content', and so on are several examples. Alternatively can be an array, in which case $theme_TYPE_alter() is invoked for each value in the array. When Form API is using $this->alter() to execute both $theme_form_alter() and $theme_form_FORM_ID_alter() implementations, it passes array('form', 'form_' . $form_id) for $type.

mixed $data: The variable that will be passed to $theme_TYPE_alter() implementations to be altered. The type of this variable depends on the value of the $type argument. For example, when altering a 'form', $data will be a structured array. When altering a 'profile', $data will be an object.

mixed $context1: (optional) An additional variable that is passed by reference.

mixed $context2: (optional) An additional variable that is passed by reference. If more context needs to be provided to implementations, then this should be an associative array as described above.

Overrides ThemeManagerInterface::alter

File

core/lib/Drupal/Core/Theme/ThemeManager.php, line 456

Class

ThemeManager: Provides the default implementation of a theme manager.

Namespace

Drupal\Core\Theme

Code

public function alter($type, &$data, &$context1 = NULL, &$context2 = NULL) {
  $theme = $this
    ->getActiveTheme();
  $this
    ->alterForTheme($theme, $type, $data, $context1, $context2);
}

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