Implements Drupal\Component\Plugin\Derivative\DerivativeInterface::getDerivativeDefinitions().
Overrides DerivativeInterface::getDerivativeDefinitions
public function getDerivativeDefinitions(array $base_plugin_definition) {
// This isn't strictly necessary, but it helps reduce clutter in
// DerivativePluginTest::testDerivativeDecorator()'s $expected variable.
// Since derivative definitions don't need further deriving, we remove this
// key from the returned definitions.
unset($base_plugin_definition['derivative']);
$derivatives = array(
// Adding a NULL key signifies that the base plugin may also be used in
// addition to the derivatives. In this case, we allow the administrator
// to add a generic layout block to the page.
NULL => $base_plugin_definition,
// We also allow them to add a customized one. Here, we just mock the
// customized one, but in a real implementation, this would be fetched
// from some config() object.
'foo' => array(
'label' => 'Layout Foo',
) + $base_plugin_definition,
);
return $derivatives;
}