django-rest-framework-tricks 0.2.4

Collection of various tricks for Django REST framework.

Collection of various tricks for Django REST framework.

Prerequisites

• Django 1.8, 1.9, 1.10 and 1.11.
• Python 2.7, 3.4, 3.5, 3.6

Dependencies

• djangorestframework: Written with 3.6.3, tested with >=3.5.0,<=3.6.3. May work on earlier versions, although not guaranteed.

Installation

1. Install latest stable version from PyPI:

   pip install django-rest-framework-tricks
   

   or latest stable version from GitHub:

   pip install https://github.com/barseghyanartur/django-rest-framework-tricks/archive/stable.tar.gz
   

2. Add rest_framework and rest_framework_tricks to INSTALLED_APPS:

   INSTALLED_APPS = (
       # ...
       # REST framework
       'rest_framework',
   
       # REST framework tricks (this package)
       'rest_framework_tricks',
   
       # ...
   )
   

Documentation

Documentation is available on Read the Docs.

Main features and highlights

• Nested serializers: Nested serializers for non-relational fields.

Usage examples

Nested serializers

Nested serializers for non-relational fields.

Our imaginary Book model consists of the following (non-relational) Django model fields:

• title: CharField
• description: TextField
• summary: TextField
• publication_date: DateTimeField
• state: CharField (with choices)
• isbn: CharField
• price: DecimalField
• pages: IntegerField
• stock_count: IntegerField

In our REST API, we want to split the Book serializer into parts using nested serializers to have the following structure:

{
    "id": "",
    "title": "",
    "description": "",
    "summary": "",
    "publishing_information": {
        "publication_date": "",
        "isbn": "",
        "pages": ""
    },
    "stock_information": {
        "stock_count": "",
        "price": "",
        "state": ""
    }
}

Sample model

The only variation from standard implementation here is that we declare two NestedProxyField fields on the Book model level for to be used in BookSerializer serializer.

Note, that the change does not cause model change (no migrations or whatsoever).

Required imports

from django.db import models

from rest_framework_tricks.models.fields import NestedProxyField

Model definition

BOOK_PUBLISHING_STATUS_PUBLISHED = 'published'
BOOK_PUBLISHING_STATUS_NOT_PUBLISHED = 'not_published'
BOOK_PUBLISHING_STATUS_IN_PROGRESS = 'in_progress'
BOOK_PUBLISHING_STATUS_CHOICES = (
    (BOOK_PUBLISHING_STATUS_PUBLISHED, "Published"),
    (BOOK_PUBLISHING_STATUS_NOT_PUBLISHED, "Not published"),
    (BOOK_PUBLISHING_STATUS_IN_PROGRESS, "In progress"),
)
BOOK_PUBLISHING_STATUS_DEFAULT = BOOK_PUBLISHING_STATUS_PUBLISHED


class Book(models.Model):
    """Book."""

    title = models.CharField(max_length=100)
    description = models.TextField(null=True, blank=True)
    summary = models.TextField(null=True, blank=True)
    publication_date = models.DateField()
    state = models.CharField(max_length=100,
                             choices=BOOK_PUBLISHING_STATUS_CHOICES,
                             default=BOOK_PUBLISHING_STATUS_DEFAULT)
    isbn = models.CharField(max_length=100, unique=True)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    pages = models.PositiveIntegerField(default=200)
    stock_count = models.PositiveIntegerField(default=30)

    # List the fields for `PublishingInformationSerializer` nested
    # serializer. This does not cause a model change.
    publishing_information = NestedProxyField(
        'publication_date',
        'isbn',
        'pages',
    )

    # List the fields for `StockInformationSerializer` nested serializer.
    # This does not cause a model change.
    stock_information = NestedProxyField(
        'stock_count',
        'price',
        'state',
    )

    class Meta(object):
        """Meta options."""

        ordering = ["isbn"]

    def __str__(self):
        return self.title

Sample serializers

At first, we add nested_proxy_field property to the Meta class definitions of PublishingInformationSerializer and StockInformationSerializer nested serializers.

Then we define our (main) BookSerializer class, which is going to be used as a serializer_class of the BookViewSet. We inherit the BookSerializer from rest_framework_tricks.serializers.HyperlinkedModelSerializer instead of the one of the Django REST framework. There’s also a rest_framework_tricks.serializers.ModelSerializer available.

Required imports

from rest_framework import serializers
from rest_framework_tricks.serializers import (
    HyperlinkedModelSerializer,
)

from .models import Book

Defining the serializers

Note

If you get validation errors about null-values, add allow_null=True next to the required=False for serializer field definitions.

Nested serializer

class PublishingInformationSerializer(serializers.ModelSerializer):
    """Publishing information serializer."""

    publication_date = serializers.DateField(required=False)
    isbn = serializers.CharField(required=False)
    pages = serializers.IntegerField(required=False)

    class Meta(object):
        """Meta options."""

        model = Book
        fields = (
            'publication_date',
            'isbn',
            'pages',
        )
        # Note, that this should be set to True to identify that
        # this serializer is going to be used as `NestedProxyField`.
        nested_proxy_field = True

Nested serializer

class StockInformationSerializer(serializers.ModelSerializer):
    """Stock information serializer."""

    class Meta(object):
        """Meta options."""

        model = Book
        fields = (
            'stock_count',
            'price',
            'state',
        )
        # Note, that this should be set to True to identify that
        # this serializer is going to be used as `NestedProxyField`.
        nested_proxy_field = True

Main serializer to be used in the ViewSet

# Note, that we are importing the ``HyperlinkedModelSerializer`` from
# the `rest_framework_tricks.serializers`. Names of the serializers
# should match the names of model properties set with ``NestedProxyField``
# fields.
class BookSerializer(HyperlinkedModelSerializer):
    """Book serializer."""

    publishing_information = PublishingInformationSerializer(required=False)
    stock_information = StockInformationSerializer(required=False)

    class Meta(object):
        """Meta options."""

        model = Book
        fields = (
            'url',
            'id',
            'title',
            'description',
            'summary',
            'publishing_information',
            'stock_information',
        )

Sample ViewSet

Absolutely no variations from standard implementation here.

Required imports

from rest_framework.viewsets import ModelViewSet
from rest_framework.permissions import AllowAny

from .models import Book
from .serializers import BookSerializer

ViewSet definition

class BookViewSet(ModelViewSet):
    """Book ViewSet."""

    queryset = Book.objects.all()
    serializer_class = BookSerializer
    permission_classes = [AllowAny]

Sample OPTIONS call

OPTIONS /books/api/books/
HTTP 200 OK
Allow: GET, POST, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "name": "Book List",
    "description": "Book ViewSet.",
    "renders": [
        "application/json",
        "text/html"
    ],
    "parses": [
        "application/json",
        "application/x-www-form-urlencoded",
        "multipart/form-data"
    ],
    "actions": {
        "POST": {
            "id": {
                "type": "integer",
                "required": false,
                "read_only": true,
                "label": "ID"
            },
            "title": {
                "type": "string",
                "required": true,
                "read_only": false,
                "label": "Title",
                "max_length": 100
            },
            "description": {
                "type": "string",
                "required": false,
                "read_only": false,
                "label": "Description"
            },
            "summary": {
                "type": "string",
                "required": false,
                "read_only": false,
                "label": "Summary"
            },
            "publishing_information": {
                "type": "nested object",
                "required": false,
                "read_only": false,
                "label": "Publishing information",
                "children": {
                    "publication_date": {
                        "type": "date",
                        "required": false,
                        "read_only": false,
                        "label": "Publication date"
                    },
                    "isbn": {
                        "type": "string",
                        "required": false,
                        "read_only": false,
                        "label": "Isbn"
                    },
                    "pages": {
                        "type": "integer",
                        "required": false,
                        "read_only": false,
                        "label": "Pages"
                    }
                }
            },
            "stock_information": {
                "type": "nested object",
                "required": false,
                "read_only": false,
                "label": "Stock information",
                "children": {
                    "stock_count": {
                        "type": "integer",
                        "required": false,
                        "read_only": false,
                        "label": "Stock count"
                    },
                    "price": {
                        "type": "decimal",
                        "required": true,
                        "read_only": false,
                        "label": "Price"
                    },
                    "state": {
                        "type": "choice",
                        "required": false,
                        "read_only": false,
                        "label": "State",
                        "choices": [
                            {
                                "value": "published",
                                "display_name": "Published"
                            },
                            {
                                "value": "not_published",
                                "display_name": "Not published"
                            },
                            {
                                "value": "in_progress",
                                "display_name": "In progress"
                            }
                        ]
                    }
                }
            }
        }
    }
}

Unlimited nesting depth

Unlimited nesting depth is supported.

Our imaginary Author model could consist of the following (non-relational) Django model fields:

• salutation: CharField
• name: CharField
• email: EmailField
• birth_date: DateField
• biography: TextField
• phone_number: CharField
• website: URLField
• company: CharField
• company_phone_number: CharField
• company_email: EmailField
• company_website: URLField

In our REST API, we could split the Author serializer into parts using nested serializers to have the following structure:

{
    "id": "",
    "salutation": "",
    "name": "",
    "birth_date": "",
    "biography": "",
    "contact_information": {
        "personal_contact_information": {
            "email": "",
            "phone_number": "",
            "website": ""
        },
        "business_contact_information": {
            "company": "",
            "company_email": "",
            "company_phone_number": "",
            "company_website": ""
        }
    }
}

Our model would have to be defined as follows (see Advanced usage examples for complete model definition):

class Author(models.Model):
    """Author."""

    # ...

    # List the fields for `PersonalContactInformationSerializer` nested
    # serializer. This does not cause a model change.
    personal_contact_information = NestedProxyField(
        'email',
        'phone_number',
        'website',
    )

    # List the fields for `BusinessContactInformationSerializer` nested
    # serializer. This does not cause a model change.
    business_contact_information = NestedProxyField(
        'company',
        'company_email',
        'company_phone_number',
        'company_website',
    )

    # List the fields for `ContactInformationSerializer` nested
    # serializer. This does not cause a model change.
    contact_information = NestedProxyField(
        'personal_contact_information',
        'business_contact_information',
    )

    # ...

See the Advanced usage examples for complete example.

Demo

Run demo locally

In order to be able to quickly evaluate the django-rest-framework-tricks, a demo app (with a quick installer) has been created (works on Ubuntu/Debian, may work on other Linux systems as well, although not guaranteed). Follow the instructions below to have the demo running within a minute.

Grab and run the latest rest_framework_tricks_demo_installer.sh demo installer:

wget -O - https://raw.github.com/barseghyanartur/django-rest-framework-tricks/master/examples/rest_framework_tricks_demo_installer.sh | bash

Open your browser and test the app.

http://127.0.0.1:8001/books/api/

Testing

Project is covered with tests.

To test with all supported Python/Django versions type:

tox

To test against specific environment, type:

tox -e py36-django110

To test just your working environment type:

./runtests.py

To run a single test in your working environment type:

./runtests.py src/rest_framework_tricks/tests/test_nested_proxy_field.py

Or:

./manage.py test rest_framework_tricks.tests.test_nested_proxy_field

It’s assumed that you have all the requirements installed. If not, first install the test requirements:

pip install -r examples/requirements/test.txt

Writing documentation

Keep the following hierarchy.

=====
title
=====

header
======

sub-header
----------

sub-sub-header
~~~~~~~~~~~~~~

sub-sub-sub-header
^^^^^^^^^^^^^^^^^^

sub-sub-sub-sub-header
++++++++++++++++++++++

sub-sub-sub-sub-sub-header
**************************

License

GPL 2.0/LGPL 2.1

Support

For any issues contact me at the e-mail given in the Author section.

Author

Artur Barseghyan <[e-mail]>