Full Stack Build Part 1 - Building and Deploying an API

What you will learn#

Creating an API
Setting Cors Headers
Testing an API
Deploying an API

Setup#

Open up terminal in your django folder
activate your virtual environment source ./djangoenv/bin/activate
generate a new django project django-admin startproject todoproject
cd into the todoproject folder
test your dev server python manage.py runserver

Creating the API#

create a new app django-admin startapp todos

DjangoRestFramework#

When creating an API previously we did without any external help and making basic crud routes ended being a bit tedious...

write all crud functions individually
we had to convert our data to json then back to a dictionary to send back as json
the shape of the data isn't we would traditionally would expect
we had to turn off CSRF security and other security features to make work

DjangoRestFramework fixes all the above and creates a nice abstraction for creating REST API's with django. Let's do it!

DJANGO REST FRAMEWORK DOCUMENTATION

install djangorestframework pip install djangorestframework
install djangorestframework and the todos app in settings.py

INSTALLED_APPS = [    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    'todos.apps.TodosConfig',    'rest_framework']

Creating our Model#

todos/models.py

from django.db import models
class Todo(models.Model):    subject = models.CharField(max_length=100)    details = models.CharField(max_length=100)

Make and Run Migrations#

python manage.py makemigrations
python manage.py migrate

Making Our Serializer#

Serializing objects into json strings and then turning them back into python dictionaries can be a tedious process. With djangorestframework, we can build a serializer for our model that handles all this for us along with arranging the data in a more traditional form.

create a serializers.py in our todos app

from .models import Todofrom django.contrib.auth.models import User, Groupfrom rest_framework import serializers
# Our TodoSerializerclass TodoSerializer(serializers.HyperlinkedModelSerializer):    class Meta:        # The model it will serialize        model = Todo        # the fields that should be included in the serialized output        fields = ['id', 'subject', 'details']

Creating Our Viewset#

djangorestframework has classes for building out views called ViewSets. With these we can wire up all our CRUD routes pretty easily.

in todos/views.py


from .models import Todofrom rest_framework import viewsetsfrom rest_framework import permissionsfrom .serializers import TodoSerializer

class TodoViewSet(viewsets.ModelViewSet):    ## The Main Query for the index route    queryset = Todo.objects.all()    # The serializer class for serializing output    serializer_class = TodoSerializer    # optional permission class set permission level    permission_classes = [permissions.AllowAny] #Coule be [permissions.IsAuthenticated]

Setting Up Our Router#

To make sure all of the ViewSets methods connects to the rights urls, djangorestframework provides with a router to wire it all up. Let's head over to our urls.py.


from django.contrib import adminfrom django.urls import path, includefrom rest_framework import routersfrom todos.views import TodoViewSet
# create a new routerrouter = routers.DefaultRouter()# register our viewsetsrouter.register(r'todos', TodoViewSet) #register "/todos" routes

urlpatterns = [    # add all of our router urls    path('', include(router.urls)),    path('admin/', admin.site.urls),]

Testing the API#

fire up postman
create 3-4 todos with post requests to /todos/
get the full list with a get request to /todos/
see one todo with a get request to /todos/<id>
edit a todo with a put request to /todos/<id>
delete a todo with delete request to /todos/<id>

Deploying the API#

Now it's time to deploy the API, so first we have setup to do...

install the libraries we need... pip install django-heroku gunicorn django-cors-headers
- gunicorn: web server to run in production
- django-heroku: configures our app for heroku deployment
- django-cors-headers: will be used to handle cors
  If you have any issues with installing psychopg2 (django-heroku dep), it is either cause you don't have x-code installed on mac or on linux you need to install "libpq-dev", on ubuntu based systems the command would be sudo apt-get install libpq-dev

setting up django-heroku#

In settings.py

at the top import django-heroku import django_heroku
at the bottom add django_heroku.settings(locals())

setting up django-cors-headers#