State

Description

Thay đổi hành vi (behavior) của object khi trạng thái bên trong của object thay đổi

Example

Quản lí Order:

• OrderManager:

  class OrderManager
  {
      private OrderState $state;
  
      public function __construct(OrderState $state)
      {
          $this->setState($state);
      }
  
      public function setState(OrderState $state)
      {
          $this->state = $state;
      }
  
      public function nextProceed()
      {
          $this->state->nextProceed($this);
      }
  
      public function handle()
      {
          return $this->state->handle();
      }
  }

• OrderState:

  interface OrderState
  {
      public function nextProceed(OrderManager $context);
  
      public function handle();
  }

• CreatedState:

  class CreatedState implements OrderState
  {
      public function nextProceed(OrderManager $manager)
      {
          $manager->setState(new PaymentState());
      }
  
      public function handle()
      {
          // do something
      }
  }

• PaymentState:

  class PaymentState implements OrderState
  {
      public function nextProceed(OrderManager $manager)
      {
          $manager->setState(new DoneState());
      }
  
      public function handle()
      {
          // do something
      }
  }

• DoneState:

  class DoneState implements OrderState
  {
      public function nextProceed(OrderManager $manager)
      {
      }
  
      public function handle()
      {
          // do something
      }
  }