Django RESTful Framework

What is MVT?

Model: Data structuring

View: Where data flows

Template: Where data is displayed

What is API?

• Application Programming Interface

  • Developer interface

    • Developers only need Data!

Request

: Requests are sent via URL!

Data notation

: Convention

• JSON

  • JavaScript Object Notation

  • Javascript object-style notation

• XML

  • eXtended Markup Language (W3C, 1996)

Why not HTML?

: Key values are not reflected!

• That's why XML was introduced, allowing us to define tags as we wish

Why JSON

• XML is longer due to closing tags

  • Money

What we need to do

: In Django, provide only data in JSON format!

JSON ... and then?

JSON Concept

Reasons for separating Javascript & framework

1. For better user experience

   • Bad UX -> No Users -> No Money

   • data -> What do humans like?

   • Mobile applications (web)

   • churn (attrition rate)

   • JS essential (Adobe Flash)

2. Because separation is convenient

Reinstalling Django

pip uninstall django

pip install django==2.1.15

Using Faker

Install faker

pip install faker

Create dummy data

In [1]: from faker import Faker                                                                                     

In [2]: f = Faker()                                                                                                 

In [3]: f.text()                                                                                                    
Out[3]: 'Soldier live various argue many expect important once. Next possible whom I.\nSome national left wall score few else always. Action less culture spring any night.'

In [4]: f.name()                                                                                                    
Out[4]: 'Jenna Davis'

In [5]: f.paragraph()                                                                                               
Out[5]: 'Improve knowledge hot matter himself. Growth water act bill to can discuss there. Follow out person vote action someone.'

In [6]: f.paragraph(4)                                                                                              
Out[6]: 'Early program four bill. Computer ...'

RESTful API

Reference: https://meetup.toast.com/posts/92

: A way to organize URLs neatly (common rules / conventions)

RESTful

1. HTTP verb (GET, POST)

2. Composed of nouns (plural form)

Rules

• Don't put verbs in URL! -> Use HTTP method

  • C (POST)

    • (POST) / articles /

  • R (GET)

    • index (all information) - (GET) / articles /

    • detail (one information) - (GET) / articles / <id>

  • U (PUT/PATCH)

    • (PUT) / articles / <id>

  • D (DELETE)

    • (DELETE) / articles / <id>

• Only put objects in URL -> In plural form

  • Data

API related URLs

1. subdomain

   • ex)

     • lab.ssafy.com

     • api.github.com

2. Separated URL /api/

   • ssafy.com/api/lectures/

   • github.com/api/repos/

3. versioning

   • ssafy.com/api/v1/lectures/

   • POST /api/articles/1/like/

   • POST /api/articles/1/comments/like/

Django REST Framework (DRF)

Install djangorestframework

pip install djangorestframework

Check if installed

$ pip show djangorestframework
Name: djangorestframework
Version: 3.11.0
Summary: Web APIs for Django, made easy.
Home-page: https://www.django-rest-framework.org/
Author: Tom Christie
Author-email: [e-mail]
License: BSD
Location: /home/chloe/.local/lib/python3.6/site-packages
Requires: django
Required-by: drf-serializer-cache

Serialize (Serialization)

Format conversion (data transmission/movement)

dict -> JSON (stringify, serialize)

JSON -> dict (parse, deserialize)

Serialization

: Object(language, database) -> String (JSON)

CREATE

Create Process

Pretty error output with raise_exception

ex)

@api_view(['POST'])
def article_create(request):
    # Create article
    serializer = ArticleSerializer(data=request.data)
    if serializer.is_valid(raise_exception=True):
        serializer.save()
    return Response(serializer.data)

Send only one

Single Response

Error message

Error Message

yasg

• Automatically generates API related documentation

Install DRF yasg

https://drf-yasg.readthedocs.io/en/stable/readme.html

pip install drf-yasg

Loading dummy data as JSON

Put dummy.json in fixtures folder

├── api
│   ├── __init__.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── db.sqlite3
├── manage.py
└── musics
    ├── admin.py
    ├── apps.py
    ├── fixtures
    │   └── dummy.json
    ├── __init__.py
    ├── migrations
    ├── models.py
    ├── serializers.py
    ├── tests.py
    ├── urls.py
    └── views.py

7 directories, 29 files

Put dummy.json into DB with loaddata

$ python manage.py loaddata dummy.json
Installed 14 object(s) from 1 fixture(s)

Dump data from DB with dumpdata

$ python manage.py dumpdata musics
[{"model": "musics.artist", "pk": 1, "fields": {"name": "Coldplay"}}, {"model": "musics.artist", "pk": 2, "fields": {"name": "Maroon5"}}, {"model": "musics.music", "pk": 1, "fields": {"artist": 2, "title": "Girls Like You"}}, {"model": "musics.music", "pk": 2, "fields": {"artist": 2, "title": "Sunday Morning"}}, {"model": "musics.music", "pk": 3, "fields": {"artist": 1, "title": "viva la vida"}}, {"model": "musics.music", "pk": 4, "fields": {"artist": 1, "title": "paradise"}}, {"model": "musics.comment", "pk": 1, "fields": {"music": 1, "content": "Girls Like You!!!"}}, {"model": "musics.comment", "pk": 2, "fields": {"music": 1, "content": "Maroon Five is awesome!"}}, {"model": "musics.comment", "pk": 3, "fields": {"music": 2, "content": "Sunday Morning~~~"}}, {"model": "musics.comment", "pk": 4, "fields": {"music": 2, "content": "But tomorrow is Monday"}}, {"model": "musics.comment", "pk": 5, "fields": {"music": 3, "content": "Still good after 10 years"}}, {"model": "musics.comment", "pk": 6, "fields": {"music": 3, "content": "I feel like I became a king!"}}, {"model": "musics.comment", "pk": 7, "fields": {"music": 4, "content": "Paradise para-para-paradise~"}}, {"model": "musics.comment", "pk": 8, "fields": {"music": 4, "content": "Hidden masterpiece!!!"}}]

Create JSON file from dumped data with dumpdata

This way they stick together

python manage.py dumpdata musics > dump.json

Make it pretty with indenting

--indent 2 -> Give indenting of 2

python manage.py dumpdata musics --indent 2 > dump2.json

result

[
{
  "model": "musics.artist",
  "pk": 1,
  "fields": {
    "name": "Coldplay"
  }
},
{
  "model": "musics.artist",
  "pk": 2,
  "fields": {
    "name": "Maroon5"
  }
},
{
  "model": "musics.music",
  "pk": 1,
  "fields": {
    "artist": 2,
    "title": "Girls Like You"
  }
},
{
  "model": "musics.music",
  "pk": 2,
  "fields": {
    "artist": 2,
    "title": "Sunday Morning"
  }
},
{
  "model": "musics.music",
  "pk": 3,
  "fields": {
    "artist": 1,
    "title": "viva la vida"
  }
},
{
  "model": "musics.music",
  "pk": 4,
  "fields": {
    "artist": 1,
    "title": "paradise"
  }
},
{
  "model": "musics.comment",
  "pk": 1,
  "fields": {
    "music": 1,
    "content": "Girls Like You!!!"
  }
},
{
  "model": "musics.comment",
  "pk": 2,
  "fields": {
    "music": 1,
    "content": "Maroon Five is awesome!"
  }
},
{
  "model": "musics.comment",
  "pk": 3,
  "fields": {
    "music": 2,
    "content": "Sunday Morning~~~"
  }
},
{
  "model": "musics.comment",
  "pk": 4,
  "fields": {
    "music": 2,
    "content": "But tomorrow is Monday"
  }
},
{
  "model": "musics.comment",
  "pk": 5,
  "fields": {
    "music": 3,
    "content": "Still good after 10 years"
  }
},
{
  "model": "musics.comment",
  "pk": 6,
  "fields": {
    "music": 3,
    "content": "I feel like I became a king!"
  }
},
{
  "model": "musics.comment",
  "pk": 7,
  "fields": {
    "music": 4,
    "content": "Paradise para-para-paradise~"
  }
},
{
  "model": "musics.comment",
  "pk": 8,
  "fields": {
    "music": 4,
    "content": "Hidden masterpiece!!!"
  }
}
]