djangogirls/django-girls.md

django girls blog

Target: create a blog using django.

01 Your first Django project!

1.1 Create Django project

• Command to start Django project:

$ django-admin startproject mysite.

Generating following dir structure:

djangogirls
├── manage.py
├── mysite
│   ├── __init__.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── myvenv
│   └── ...
└── requirements.txt

where:

• setting.pyL: helps with management of the site.
  • contains configuration of the website
• urls.py: contains a list of patterns used by urlresolve

1.2 Change settings of django website

Edit mysite/settings.py:

1. Change timezone: `TIME_ZONE=Australia/Canberra'
2. Change language: `LANGUAGE_CODE = 'en-us'
3. Add a path for static files (e.g. CSS and static files): STATIC_ROOT = os.path.join(BASE_DIR, 'static')
4. Add allowed host site: ALLOWED_HOST = ['127.0.0.1', '.amazonaws.com'] for using cloud9

1.3 Set up a database

Django support multiple databases, to store data. sqlite3 is the default one, which is already set up as shown in mysite/settings.py:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

After confirming database settings, migrate the project python manage.py migrate

1.4 Starting the web server

python manage.py runserver

2. Django models

Target: create objects that store all posts in the blog.

2.1 Objects

In OOP, object containing member data and member function. We try to model the blog's objects as well.

Q:

• How will we model blog posts?
• What is a blog post?
• What properties should it have?

A:

• Blog posts need
  • text with content and title
  • author
  • date of created/published

Object's data can be shown as below:

Post
-------
title
text
author
created_date
published_date

Blog object's method:

• publish

2.2 Django model

A model in Django is a special kind of obj, saved in database. Analogy: A model in database is like a spreadsheet with columns (fields) and rows (data).

2.2.1 Creating and app

For organization, we create a separate app inside the web project, which contains logic and model.

$ python manage.py startapp blog

It created a dir called /blog that containing scripts:

djangogirls
├── blog
│   ├── admin.py
│   ├── apps.py
│   ├── __init__.py
│   ├── migrations
│   │   └── __init__.py
│   ├── models.py
│   ├── tests.py
│   └── views.py
|...

After creating app, mysite/settings.py should be changed to let Django notice the app.

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    # first party
    'blog.apps.BlogConfig',
]

• blog.apps.BlogConfig is the class that in blog/apps.py script

2.2.2 Creating a blog post model

For each app, there is a models.py that contains models (obj), modify it to contain post obj

from django.db import models
from django.conf import settings
from django.utils import timezone

class Post(models.Model):
    author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    title = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(default=timezone.now)
    published_date = models.DateTimeField(blank=True, null=True)

    def publish(self):
        self.published_date = timezone.now()
        self.save()

    def __str__(self):
        return self.title

Explaining Post class:

• models.Model the base class the Post class inherit from. It means Post is a Django Model, so Django can save it in database
• Properties are defined as Django's model data type:
  • models.CharField: A Django model class that define text with limited number of char
  • models.TextField: long text w/o limit
  • Check django models->fields->field-types

2.2.3 Create tables for models in database

After creating new model, we need to add it into database:

1. Let Django know there is change: python manage.py makemigrations blog
   1. So, Django will prepare a migration file
2. After prepared migration file blog/migrations/0001_initial.py, apply it to database: python manage.py migrate blog

3. Django admin

To adding/editing posts, need use Django admin

3.1 Add Post models into admin site

Edit blog/admin.py

from django.contrib import admin
from .models import Post

admin.site.register(Post)

3.2 Add superuser to get access

python manage.py createsuperuser

3.3 Add/Edit post in admin site

Start webserver python manage.py runserver then go to http://127.0.0.1/admin

In the post, we can find it has multiple attributes/members including:

• author
• Title
• Text
• Created date
• Published date

They are all forms that we created in Post model

4. Deploy (Omit)