Set Django model field by choice text name

Question

Consider the following example model:

class MyModel(models.Model):
    TYPE_ONE = 1
    TYPE_TWO = 2
    TYPE_CHOICES = (
        (TYPE_ONE, "One"),
        (TYPE_TWO, "Two"),
    )

    type = models.SmallIntegerField(choices=TYPE_CHOICES)
    #  ... other fields

This works well internally, as I now have a 'constant' which I can reuse throughout my code to refer to each type .

However, when this model gets serialized and sent to the client as JSON through a custom API Controller implementation, it turns the type into it's textual representation. It might look like this:

{
    'id': 1,
    'type': 'One'
}

This is fine, however I'd like to be able to set the field value based on this text version (the consumer of my API wants to be able to pass friendly strings, not ints).

When constructing a model instance, how can I set type to One , and have it automatically convert it into the relevant int ?

Something like:

m = MyModel()
m.type = "One"
m.save()  # throws a ValueError

Thanks

Answer 1

您可以使用以下解决方法：

m.type = dict((key,value) for (value,key) in MyModel.TYPE_CHOICES)['One']

Answer 2

You should make one property for it. So you can use whenever you want.

class MyModel(object):
     TYPE_CHOICES = ((1, "One"), (2, "Two"))
     type = models.SmallIntegerField(choices=TYPE_CHOICES)

     def getx(self):
         return self.type

     def setx(self, val):
           ch = filter(lambda y: y if y[1] == val else None, self.TYPE_CHOICES)

         self.type = ch[0][0]
     type_val = property(getx, setx)

then save like this.

m = MyModel()
m.type_val = "One"
m.save()

it will save into type.

Hopefully, it will work for you. :)