Update meta inheritance docs to include serializer

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Ryan P Kilby 2017-01-03 14:10:19 -05:00
parent 79e2c9209c
commit 7b2124b042

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@ -578,16 +578,6 @@ Alternative representations include serializing using hyperlinks, serializing co
For full details see the [serializer relations][relations] documentation.
## Inheritance of the 'Meta' class
The inner `Meta` class on serializers is not inherited from parent classes by default. This is the same behavior as with Django's `Model` and `ModelForm` classes. If you want the `Meta` class to inherit from a parent class you must do so explicitly. For example:
class AccountSerializer(MyBaseSerializer):
class Meta(MyBaseSerializer.Meta):
model = Account
Typically we would recommend *not* using inheritance on inner Meta classes, but instead declaring all options explicitly.
## Customizing field mappings
The ModelSerializer class also exposes an API that you can override in order to alter how serializer fields are automatically determined when instantiating the serializer.
@ -1025,6 +1015,32 @@ If any of the validation fails, then the method should raise a `serializers.Vali
The `data` argument passed to this method will normally be the value of `request.data`, so the datatype it provides will depend on the parser classes you have configured for your API.
## Serializer Inheritance
Similar to Django forms, you can extend and reuse serializers through inheritance. This allows you to declare a common set of fields or methods on a parent class that can then be used in a number of serializers. For example,
class MyBaseSerializer(Serializer):
my_field = serializers.CharField()
def validate_my_field(self):
...
class MySerializer(MyBaseSerializer):
...
Like Django's `Model` and `ModelForm` classes, the inner `Meta` class on serializers does not implicitly inherit from it's parents' inner `Meta` classes. If you want the `Meta` class to inherit from a parent class you must do so explicitly. For example:
class AccountSerializer(MyBaseSerializer):
class Meta(MyBaseSerializer.Meta):
model = Account
Typically we would recommend *not* using inheritance on inner Meta classes, but instead declaring all options explicitly.
Additionally, the following caveats apply to serializer inheritance:
* Normal Python name resolution rules apply. If you have multiple base classes that declare a `Meta` inner class, only the first one will be used. This means the childs `Meta`, if it exists, otherwise the `Meta` of the first parent, etc.
* Its possible to declaratively remove a `Field` inherited from a parent class by setting the name to be `None` on the subclass. You can only use this technique to opt out from a field defined declaratively by a parent class; it wont prevent the `ModelSerializer` from generating a default field. To opt-out from default fields, see [Specifying which fields to include](#specifying-which-fields-to-include).
## Dynamically modifying fields
Once a serializer has been initialized, the dictionary of fields that are set on the serializer may be accessed using the `.fields` attribute. Accessing and modifying this attribute allows you to dynamically modify the serializer.