django-api 0.1

Cleanly specify and validate your Django APIs

Django API is a way to cleanly specify and validate your Django APIs in a single block of code. It provides a method to keep your API documentation and implementation consistent.

Dependencies

None

Installation

To use django_api in your Django project it needs to be accessible by your Python installation:

$ pip install django-api

(or simply place the django_api directory in your $PYTHON_PATH)

Django Setup

Add django_api to INSTALLED_APPS in your project’s settings.py.

Example:

INSTALLED_APPS = (
        'django.contrib.auth',
        'django.contrib.contenttypes',
        'django.contrib.sessions',
        'django.contrib.sites',
        'django.contrib.admin',
        'django_api',
)

Usage

Specify your API by using the @api decorator. The @api decorator takes a dictionary with two keys: accepts and returns.

from django_api.decorators import api
@api({
    'accepts': {
    },
    'returns': {
    }
})
def add(request, *args, **kwargs):

accepts

Describe the query parameters your API accepts by listing them out in the accepts dictionary. Each entry in the accepts section maps a name to a Django form type. Received query parameters are automatically converted to the specified type. If the parameter does not conform to the specification the query fails to validate (see below). Once validated, the variables will be placed in the request dictionary for use within the view.

'accepts': {
    'x': forms.IntegerField(min_value=0),
    'y': forms.IntegerField(max_value=10, required=False),
    'u': User(),
}

returns

By default, the @api decorator checks that the returned response is of JSON type.

Specify the valid returned HTTP codes by listing them out in the returns dictionary. Each entry in the dictionary maps a HTTP response code to a helpful message, explaining the outcome of the action. The helpful message is for documentation purposes only. If the response does not conform to the specification, the query will fail to validate (see below).

'returns': {
    200: 'Addition successful',
    403: 'User does not have permission',
    404: 'Resource not found',
    404: 'User not found',
}

Putting it all together, we have

from django_api.decorators import api
@api({
    'accepts': {
        'x': forms.IntegerField(min_value=0),
        'y': forms.IntegerField(max_value=10, required=False),
    },
    'returns': {
        200: 'Addition successful',
        403: 'User does not have permission',
        404: 'Resource not found',
        404: 'User not found',
    }
})
def add(request, *args, **kwargs):
    if not request.GET['x'] == 10:
        return JsonResponseForbidden()  # 403

    return HttpResponse()  # 200

Validation

If validation fails, a HTTP 400 - Bad request is returned to the client. For safety, django_api will perform validation only if settings.DEBUG = True. This ensures that production code always remains unaffected.

Testing

Run the tests with the folllowing command

python manage.py test django_api

Advanced usage

Django Models

@accepts can be used to also accept your Django models through the object’s id. For a Model Model, Django expects the query parameter to be name model-id.

'accepts': {
    'x': forms.IntegerField(min_value=0),
    'y': forms.IntegerField(max_value=10, required=False),
    'u': User(),
}

You can also simply choose to validate either only the parameters the API accepts, or the return values of the API.

Example:

from django_api.decorators import api_accepts
@api_accepts({
    'x': forms.IntegerField(min_value=0),
    'y': forms.IntegerField(min_value=0),
})
def add(request, *args, **kwargs):
    x = request.POST['x']
    y = request.POST['y']

    # x and y are integers already.
    return HttpResponse('%d' % (x + y))


from django_api.decorators import api_returns
@api_returns({
    200: 'Operation successful',
    403: 'User does not have permission',
    404: 'Resource not found',
    404: 'User not found',
})
def add(request, *args, **kwargs):
    if not request.user.is_superuser:
        return JsonResponseForbidden()  # 403

    return HttpResponse()  # 200