Usage

The DJA package implements a custom renderer, parser, exception handler, and pagination. To get started enable the pieces in settings.py that you want to use.

Many features of the JSON:API format standard have been implemented using Mixin classes in serializers.py. The easiest way to make use of those features is to import ModelSerializer variants from rest_framework_json_api instead of the usual rest_framework

Configuration

We suggest that you copy the settings block below and modify it if necessary.

REST_FRAMEWORK = {
    'PAGE_SIZE': 10,
    'EXCEPTION_HANDLER': 'rest_framework_json_api.exceptions.exception_handler',
    'DEFAULT_PAGINATION_CLASS':
        'rest_framework_json_api.pagination.PageNumberPagination',
    'DEFAULT_PARSER_CLASSES': (
        'rest_framework_json_api.parsers.JSONParser',
        'rest_framework.parsers.FormParser',
        'rest_framework.parsers.MultiPartParser'
    ),
    'DEFAULT_RENDERER_CLASSES': (
        'rest_framework_json_api.renderers.JSONRenderer',
        'rest_framework.renderers.BrowsableAPIRenderer',
    ),
    'DEFAULT_METADATA_CLASS': 'rest_framework_json_api.metadata.JSONAPIMetadata',
}

If PAGE_SIZE is set the renderer will return a meta object with record count and a links object with the next, previous, first, and last links. Pages can be selected with the page GET parameter. Page size can be controlled per request via the PAGINATE_BY_PARAM query parameter (page_size by default).

Serializers

It is recommended to import the base serializer classes from this package rather than from vanilla DRF. For example,

from rest_framework_json_api import serializers

class MyModelSerializer(serializers.ModelSerializers):
    # ...

Setting the resource_name

You may manually set the resource_name property on views, serializers, or models to specify the type key in the json output. In the case of setting the resource_name property for models you must include the property inside a JSONAPIMeta class on the model. It is automatically set for you as the plural of the view or model name except on resources that do not subclass rest_framework.viewsets.ModelViewSet:

Example - resource_name on View:

class Me(generics.GenericAPIView):
    """
    Current user's identity endpoint.

    GET /me
    """
    resource_name = 'users'
    serializer_class = identity_serializers.IdentitySerializer
    allowed_methods = ['GET']
    permission_classes = (permissions.IsAuthenticated, )

If you set the resource_name property on the object to False the data will be returned without modification.

Example - resource_name on Model:

class Me(models.Model):
    """
    A simple model
    """
    name = models.CharField(max_length=100)

    class JSONAPIMeta:
        resource_name = "users"

If you set the resource_name on a combination of model, serializer, or view in the same hierarchy, the name will be resolved as following: view > serializer > model. (Ex: A view resource_name will always override a resource_name specified on a serializer or model). Setting the resource_name on the view should be used sparingly as serializers and models are shared between multiple endpoints. Setting the resource_name on views may result in a different type being set depending on which endpoint the resource is fetched from.

Inflecting object and relation keys

This package includes the ability (off by default) to automatically convert json requests and responses from the python/rest_framework’s preferred underscore to a format of your choice. To hook this up include the following setting in your project settings:

JSON_API_FORMAT_KEYS = 'dasherize'

Possible values:

  • dasherize
  • camelize (first letter is lowercase)
  • capitalize (camelize but with first letter uppercase)
  • underscore

Note: due to the way the inflector works address_1 can camelize to address1 on output but it cannot convert address1 back to address_1 on POST or PUT. Keep this in mind when naming fields with numbers in them.

Example - Without format conversion:

{
    "data": [{
        "type": "identities",
        "id": 3,
        "attributes": {
            "username": "john",
            "first_name": "John",
            "last_name": "Coltrane",
            "full_name": "John Coltrane"
        },
    }],
    "meta": {
        "pagination": {
          "count": 20
        }
    }
}

Example - With format conversion set to dasherize:

{
    "data": [{
        "type": "identities",
        "id": 3,
        "attributes": {
            "username": "john",
            "first-name": "John",
            "last-name": "Coltrane",
            "full-name": "John Coltrane"
        },
    }],
    "meta": {
        "pagination": {
          "count": 20
        }
    }
}

Types

A similar option to JSON_API_FORMAT_KEYS can be set for the types:

JSON_API_FORMAT_TYPES = 'dasherize'

Example without format conversion:

{
    "data": [{
        "type": "blog_identity",
        "id": 3,
        "attributes": {
                ...
        },
        "relationships": {
            "home_town": {
                "data": [{
                    "type": "home_town",
                    "id": 3
                }]
            }
        }
    }]
}

When set to dasherize:

{
    "data": [{
        "type": "blog-identity",
        "id": 3,
        "attributes": {
                ...
        },
        "relationships": {
            "home_town": {
                "data": [{
                    "type": "home-town",
                    "id": 3
                }]
            }
        }
    }]
}

It is also possible to pluralize the types like so:

JSON_API_PLURALIZE_TYPES = True

Example without pluralization:

{
    "data": [{
        "type": "identity",
        "id": 3,
        "attributes": {
                ...
        },
        "relationships": {
            "home_towns": {
                "data": [{
                    "type": "home_town",
                    "id": 3
                }]
            }
        }
    }]
}

When set to pluralize:

{
    "data": [{
        "type": "identities",
        "id": 3,
        "attributes": {
                ...
        },
        "relationships": {
            "home_towns": {
                "data": [{
                    "type": "home_towns",
                    "id": 3
                }]
            }
        }
    }]
}

RelationshipView

rest_framework_json_api.views.RelationshipView is used to build relationship views (see the JSON API spec). The self link on a relationship object should point to the corresponding relationship view.

The relationship view is fairly simple because it only serializes Resource Identifier Objects rather than full resource objects. In most cases the following is sufficient:

from rest_framework_json_api.views import RelationshipView

from myapp.models import Order


class OrderRelationshipView(RelationshipView):
    queryset = Order.objects

The urlconf would need to contain a route like the following:

url(
    regex=r'^orders/(?P<pk>[^/.]+/relationships/(?P<related_field>[^/.]+)$',
    view=OrderRelationshipView.as_view(),
    name='order-relationships'
)

The related_field kwarg specifies which relationship to use, so if we are interested in the relationship represented by the related model field Order.line_items on the Order with pk 3, the url would be /order/3/relationships/line_items. On HyperlinkedModelSerializer, the ResourceRelatedField will construct the url based on the provided self_link_view_name keyword argument, which should match the name= provided in the urlconf, and will use the name of the field for the related_field kwarg. Also we can override related_field in the url. Let’s say we want the url to be: /order/3/relationships/order_items - all we need to do is just add field_name_mapping dict to the class:

field_name_mapping = {
        'line_items': 'order_items'
    }

Meta

You may add metadata to the rendered json in two different ways: meta_fields and get_root_meta.

On any rest_framework_json_api.serializers.ModelSerializer you may add a meta_fields property to the Meta class. This behaves in the same manner as the default fields property and will cause SerializerMethodFields or model values to be added to the meta object within the same data as the serializer.

To add metadata to the top level meta object add:

def get_root_meta(self, resource, many):
    if many:
      # Dealing with a list request
      return {
          'size': len(resource)
      }
    else:
      # Dealing with a detail request
      return {
        'foo': 'bar'
      }

to the serializer. It must return a dict and will be merged with the existing top level meta.