EN: The Invoker is associated with one or several commands. It sends a request to the command. RU: Отправитель связан с одной или несколькими командами. Он отправляет запрос команде.
| 99 | |
| 100 | |
| 101 | class Invoker: |
| 102 | """ |
| 103 | EN: The Invoker is associated with one or several commands. It sends a |
| 104 | request to the command. |
| 105 | |
| 106 | RU: Отправитель связан с одной или несколькими командами. Он отправляет |
| 107 | запрос команде. |
| 108 | """ |
| 109 | |
| 110 | _on_start = None |
| 111 | _on_finish = None |
| 112 | |
| 113 | """ |
| 114 | EN: Initialize commands. |
| 115 | |
| 116 | RU: Инициализация команд. |
| 117 | """ |
| 118 | |
| 119 | def set_on_start(self, command: Command): |
| 120 | self._on_start = command |
| 121 | |
| 122 | def set_on_finish(self, command: Command): |
| 123 | self._on_finish = command |
| 124 | |
| 125 | def do_something_important(self) -> None: |
| 126 | """ |
| 127 | EN: The Invoker does not depend on concrete command or receiver classes. |
| 128 | The Invoker passes a request to a receiver indirectly, by executing a |
| 129 | command. |
| 130 | |
| 131 | RU: Отправитель не зависит от классов конкретных команд и получателей. |
| 132 | Отправитель передаёт запрос получателю косвенно, выполняя команду. |
| 133 | """ |
| 134 | |
| 135 | print("Invoker: Does anybody want something done before I begin?") |
| 136 | if isinstance(self._on_start, Command): |
| 137 | self._on_start.execute() |
| 138 | |
| 139 | print("Invoker: ...doing something really important...") |
| 140 | |
| 141 | print("Invoker: Does anybody want something done after I finish?") |
| 142 | if isinstance(self._on_finish, Command): |
| 143 | self._on_finish.execute() |
| 144 | |
| 145 | |
| 146 | if __name__ == "__main__": |