Same name in other branches

1. 9 core/lib/Drupal/Core/Theme/ThemeManagerInterface.php \Drupal\Core\Theme\ThemeManagerInterface::alter()
2. 8.9.x core/lib/Drupal/Core/Theme/ThemeManagerInterface.php \Drupal\Core\Theme\ThemeManagerInterface::alter()
3. 11.x core/lib/Drupal/Core/Theme/ThemeManagerInterface.php \Drupal\Core\Theme\ThemeManagerInterface::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:

  $context = [
    'alterable' => &$alterable,
    'unalterable' => $unalterable,
    'foo' => 'bar',
  );
  $this->alter('my_module_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 = [
    'unalterable_object' => clone $object,
];
$this->alter('my_module_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 ['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.

See also

\Drupal\Core\Extension\ModuleHandlerInterface

File

core/lib/Drupal/Core/Theme/ThemeManagerInterface.php, line 128

Class

ThemeManagerInterface

Provides a high level access to the active theme and methods to use it.

Namespace

Drupal\Core\Theme

Code

public function alter($type, &$data, &$context1 = NULL, &$context2 = NULL);

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