allow to query an RestAPI (django-rest-framework + dynamic-rest) with same same interface as the django ORM. if fact, it work like any other database engin. you add the rest_models engin in an alternate database, the router, and add a APIMeta class to your models, and let's go.

stable branche

development status

1. Install using pip:

   pip install django-rest-models

2. Alternatively, you can install download or clone this repo and call

   pip install -e ..

this database wrapper work with

• python 2.7, 3.4, 3.5
• django 1.8 , 1.9, 1.10

on the api, this is tested against

• django-rest-framework 3.4, 3.5
• dynamic-rest 1.5, 1.6

settings.py:

DATABASES = {
    'default': {
        ...
    },
    'api': {
        'ENGINE': 'rest_models.backend',
        'NAME': 'https://requestb.in/',
        'USER': 'userapi',
        'PASSWORD': 'passwordapi',
        'AUTH': 'rest_models.backend.auth.BasicAuth',
    },
}

DATABASE_ROUTERS = [
    'rest_models.router.RestModelRouter',
]

models.py:

class MyModel(models.Model):
    field = models.IntegerField()
    ...

    class Meta:
        # basic django meta Stuff
        verbose_name = 'my model'

    # the only customisation that make this model special
    class APIMeta:
        pass

to allow this database adaptater to work like a relational one, the API targeted must respect some requirments

• dynamic-rest installed and all the serializers must provide it's functionnality (hinerit from DynamicModelSerializer)

each serializers must :

• provide the id fields
• provide the related field (ManyToMany and ForeignKey on Models) as DynamicRelationField
• provide the reverse related field (each ForeignKey and manyToMany add a relation on the other models. the serializer from the other model must provide the DynamicRelationField for these relation

class MenuSerializer(DynamicModelSerializer):
    pizzas = DynamicRelationField('PizzaSerializer', many=True)

    class Meta:
        model = Menu
        name = 'menu'
        fields = ('id', 'code', 'name', 'pizzas')
        deferred_fields = ('pizza_set', )


class PizzaSerializer(DynamicModelSerializer):

    toppings = DynamicRelationField(ToppingSerializer, many=True)
    menu = DynamicRelationField(MenuSerializer)

    class Meta:
        model = Pizza
        name = 'pizza'
        fields = ('id', 'name', 'price', 'from_date', 'to_date', 'toppings', 'menu')

Django rest models provide a way to check the consistency of the api with the local models via the django check framework. at each startup, it will query the api with OPTIONS to check if the local models match the remote serializers.

since this is not a real relational database, all feathure cannot be implemented. some limitations are inherited by dynamic-rest filtering system too.

• aggregations : is not implemented on the api endpoint. maybe in future release
• complexe filtering using OR : all filter passed to dynamic-rest is ANDed together, so no OR is possible
• negated AND in filtering: a negated AND give a OR, so previous limitation apply

• negated OR in filtering: since the compitation of nested filter is complexe and error prone, we disable all OR. in fact, only some nested of AND is accepted. only the final value of the Q() object can be negated

  for short, you can't :

Pizza.objects.aggregate()
Pizza.objects.annotate()
Pizza.objects.filter(Q(..) | Q(..))
Pizza.objects.exclude(Q(..) & Q(..))
Pizza.objects.exclude(Q(..) | Q(..))

but you can :

Pizza.objects.create
Pizza.objects.bulk_create
Pizza.objects.update
Pizza.objects.bulk_update
Pizza.objects.select_related
Pizza.objects.prefetch_related
Pizza.objects.values
Pizza.objects.values_list
Pizza.objects.delete
Pizza.objects.count()
Pizza.objects.filter(..., ..., ...)
Pizza.objects.filter(...).filter(...).exclude(...)
Pizza.objects.exclude(..., ...).exclude(...)
Pizza.objects.filter(Q(..) & Q(..))

some specific behaviour has been implemented to use the extra functionnality of a Rest API :

• whene inserting, the resulting model is returned by the API. the inserted model is updated with the resulting values. this imply 2 behavior:
  • if you provided a default data in the api, this data will be populated into your created instance if it was missed
  • if the serializer have some cumputed data, its data will always be used as a replacment of the one you gave to your models. (see exemple Pizza.cost which is the sum of the cost of the toppling. after each save, its value will be updated)

this database api support :

• select_related
• order_by
• only
• defer
• filter
• exclude
• delete
• update
• create
• bulk create (with retrive of pk)
• ManyToManyField
• ForeignKey

The full documentation is at http://django-rest-models.readthedocs.org/en/latest/.

• Python 2.7, 3.4, 3.5
• Django >= 1.8

Contributions and pull requests for other Django and Python versions are welcome.

If you have found a bug or if you have a request for additional functionality, please use the issue tracker on GitHub.

https://github.com/Yupeek/django-rest-models/issues

You can use this under GPLv3.

Original author: Darius BERNARD.

Thanks to django for this amazing framework.