django - Django 中状态管理的最佳实践

Question

class MyModel(models.Model):
    STATE1 = 1
    STATE2 = 2
    STATE3 = 3
    STATE_CHOICES = (
        (STATE1,"state1"),
        (STATE2,"state2"),
        (STATE3,"state3"),
    )
    .
    .
    state = models.PositiveSmallIntegerField(choices=STATE_CHOICES, default=1)

    def save(self):
       pass

    def method1(self):
       pass

    def method2(self):
       pass    

我想做的事； if state1 to state2 trigger method1, if state2 to state1 trigger method2, state2 to state3 trigger method3 等等。我如何在不使用很多“if语句”的情况下进行编码？我想编写干净的代码。

感谢您的帮助。

Answer 1

你可以根据你的状态和它的功能制作一个功能字典。然后你可以在保存方法中通过这个字典调用函数。看起来像这样；

class MyModel(models.Model):
STATE1 = 1
STATE2 = 2
STATE3 = 3
STATE_CHOICES = (
    (STATE1,"state1"),
    (STATE2,"state2"),
    (STATE3,"state3"),
)
fn_dict = {
    "state1_state2" : state1,
    "state2_state2" : state2,
    "state3_state1" : state3,
}

.
.
state = models.PositiveSmallIntegerField(choices=STATE_CHOICES, default=1)

def save(self):
    pre_saved_model = MyModel.objects.get(id=self.id) 
    self.fn_dict[pre_saved_model + "_" + self.state]()

def state1(self):
   pass

def state1(self):
   pass