interface FlashBagInterface

interface FlashBagInterface extends SessionBagInterface {
    
    /**
     * Adds a flash message for the given type.
     */
    public function add(string $type, mixed $message) : void;
    
    /**
     * Registers one or more messages for a given type.
     */
    public function set(string $type, string|array $messages) : void;
    
    /**
     * Gets flash messages for a given type.
     *
     * @param string $type    Message category type
     * @param array  $default Default value if $type does not exist
     */
    public function peek(string $type, array $default = []) : array;
    
    /**
     * Gets all flash messages.
     */
    public function peekAll() : array;
    
    /**
     * Gets and clears flash from the stack.
     *
     * @param array $default Default value if $type does not exist
     */
    public function get(string $type, array $default = []) : array;
    
    /**
     * Gets and clears flashes from the stack.
     */
    public function all() : array;
    
    /**
     * Sets all flash messages.
     */
    public function setAll(array $messages) : void;
    
    /**
     * Has flash messages for a given type?
     */
    public function has(string $type) : bool;
    
    /**
     * Returns a list of all defined types.
     */
    public function keys() : array;

}