graphene-django-plus

Tools to easily create permissioned CRUD endpoints in graphene-django.

Install

pip install graphene-django-plus

To make use of everything this lib has to offer, it is recommended to install both graphene-django-optimizer and django-guardian.

pip install graphene-django-optimizer django-guardian

What is provided

Models

• graphene_django_plus.models.GuardedModel: A django model that can be used either directly or as a mixin. It will provide a .has_perm method and a .objects.for_user that will be used by ModelType described bellow to check for object permissions. some utilities to check.

Types and Queries

• graphene_django_plus.types.ModelType: This enchances graphene_django_plus.DjangoModelType by doing some automatic prefetch optimization on setup and also checking for objects permissions on queries when it inherits from GuardedModel.

• graphene_django_plus.fields.CountableConnection: This enchances graphene.relay.Connection to provide a total_count attribute.

Here is an example describing how to use those:

import graphene
from graphene import relay
from graphene_django.fields import DjangoConnectionField

from graphene_django_plus.models import GuardedModel
from graphene_django_plus.types import ModelType
from graphene_django_plus.fields import CountableConnection


class MyModel(GuardedModel):

    class Meta:
        # guardian permissions for this model
        permissions = [
            ('can_read', "Can read the this object's info."),
        ]

    name = models.CharField(max_length=255)


class MyModelType(ModelType):

    class Meta:
        model = MyModel
        interfaces = [relay.Node]

        # Use our CountableConnection
        connection_class = CountableConnection

        # When adding this to a query, only objects with a `can_read`
        # permission to the request's user will be allowed to return to him
        # Note that `can_read` was defined in the model.
        # If the model doesn't inherid from `GuardedModel`, `guardian` is not
        # installed ot this list is empty, any object will be allowed.
        # This is empty by default
        object_permissions = [
            'can_read',
        ]

        # If unauthenticated users should be allowed to retrieve any object
        # of this type. This is not dependant on `GuardedModel` and neither
        # `guardian` and is defined as `False` by default
        allow_unauthenticated = False

        # A list of Django model permissions to check. Different from
        # object_permissions, this uses the basic Django's permission system
        # and thus is not dependant on `GuardedModel` and neither `guardian`.
        # This is an empty list by default.
        permissions = []


class Query(graphene.ObjectType):

    my_models = DjangoConnectionField(MyModelType)
    my_model = relay.Node.Field(MyModelType)

This can be queried like:

# All objects that the user has permission to see
query {
  myModels {
    totalCount
    edges {
      node {
        id
        name
      }
    }
  }
}

# Single object if the user has permission to see it
query {
  myModel(id: "<relay global ID>") {
    id
    name
  }
}

Mutations

• graphene_django_plus.mutations.BaseMutation: Base mutation using relay and some basic permission checking. Just override its .perform_mutation to perform the mutation.

• graphene_django_plus.mutations.ModelMutation: Model mutation capable of both creating and updating a model based on the existence of an id attribute in the input. All the model's fields will be automatically read from Django, inserted in the input type and validated.

• graphene_django_plus.mutations.ModelCreateMutation: A ModelMutation enforcing a "create only" rule by excluding the id field from the input.

• graphene_django_plus.mutations.ModelUpdateMutation: A ModelMutation enforcing a "update only" rule by making the id field required in the input.

• graphene_django_plus.mutations.ModelDeleteMutation: A mutation that will receive only the model's id and will delete it (if given permission, of course).

Here is an example describing how to use those:

import graphene
from graphene import relay

from graphene_django_plus.models import GuardedModel
from graphene_django_plus.types import ModelType


class MyModel(GuardedModel):

    class Meta:
        # guardian permissions for this model
        permissions = [
            ('can_write', "Can update this object's info."),
        ]

    name = models.CharField(max_length=255)


class MyModelType(ModelType):

    class Meta:
        model = MyModel
        interfaces = [relay.Node]


class MyModelUpdateMutation(ModelUpdateMutation):
    class Meta:
        model = MyModel

        # Make sure only users with the given permissions can modify the
        # object.
        # If the model doesn't inherid from `GuardedModel`, `guardian` is not
        # installed ot this list is empty, any object will be allowed.
        # This is empty by default.
        object_permissions = [
            'can_write',
        ]

        # If unauthenticated users should be allowed to retrieve any object
        # of this type. This is not dependant on `GuardedModel` and neither
        # `guardian` and is defined as `False` by default
        allow_unauthenticated = False

        # A list of Django model permissions to check. Different from
        # object_permissions, this uses the basic Django's permission system
        # and thus is not dependant on `GuardedModel` and neither `guardian`.
        # This is an empty list by default.
        permissions = []


class MyModelDeleteMutation(ModelDeleteMutation):
    class Meta:
        model = MyModel
        object_permissions = [
            'can_write',
        ]


class MyModelCreateMutation(ModelCreateMutation):
    class Meta:
        model = MyModel

    @classmethod
    def after_save(cls, info, instance, cleaned_input=None):
        # If the user created the object, allow him to modify it
        assign_perm('can_write', info.context.user, instance)


class Mutation(graphene.ObjectType):

    my_model_create = MyModelCreateMutation.Field()
    my_model_update = MyModelUpdateMutation.Field()
    my_model_delete = MyModelDeleteMutation.Field()

This can be used to create/update/delete like:

# Create mutation
mutation {
  myModelCreate(input: {name: "foobar"}) {
    myModel {
      name
    }
    errors {
      field
      message
    }
  }
}

# Update mutation
mutation {
  myModelUpdate(input: {id: "<relay global ID>" name: "foobar"}) {
    myModel {
      name
    }
    errors {
      field
      message
    }
  }
}

# Delete mutation
mutation {
  myModelDelete(input: {id: "<relay global ID>"}) {
    myModel {
      name
    }
    errors {
      field
      message
    }
  }
}

Any validation errors will be presented in the errors return value.