web\Application $catchAll

The configuration specifying a controller action which should handle all user requests. This is mainly used when the application is in maintenance mode and needs to handle all incoming requests via a single action. The configuration is an array whose first element specifies the route of the action. The rest of the array elements (key-value pairs) specify the parameters to be bound to the action. For example,

[
    'offline/notice',
    'param1' => 'value1',
    'param2' => 'value2',
]

Defaults to null, meaning catch-all is not used.