#Django

# Topic covered
* Django default User Model
* Custom User Model
    * AbstractUser vs AbstractBaseUser
* Validating objects
    * full_clean()
    * Model.clean_fields()
    * Model.clean()
    * Model.validate_unique()

1.1 𝗪𝗵𝗮𝘁 𝗵𝗮𝗽𝗽𝗲𝗻𝘀 𝘄𝗵𝗲𝗻 𝘆𝗼𝘂 𝘁𝘆𝗽𝗲 𝗮 𝗨𝗥𝗟 𝗶𝗻𝘁𝗼 𝘆𝗼𝘂𝗿 𝗯𝗿𝗼𝘄𝘀𝗲𝗿?

The process involves the browser, your computer’s operating system, your internet service provider, the server where you host the site, and services running on that server.

1. You type url.com in your browser
2. The browser looks up the IP address for the domain url.com
3. Then the browser initiate TCP connection with the server
4. The browser the sends the HTTP request to the server
5. The server processes the request and sends back a response
6. The browser then renders the content

# Topic covered
* What is Django?
* Feature in Django framework
* Advantage / Disadvantage of Django
* Design philosophies
* File Structure Info
* Script vs Modules vs Package vs Library vs Framework
* Projects vs Apps in Django
* Django vs Flask

# Topic covered
* Django Architecture
* Model View Controller(MVC)
* Model View Template (MVT)
* Why is Django called loosely coupled framework?
* django-admin and manage.py
* Write custom django-admin commands?

Django admin

Django provides a default admin interface, that provides a convenient interface to manage model data and visualize database.

It can be used to perform create, read, update and delete (CURD) operations on the model directly.

Django Models

• A Django model is the built-in feature that Django uses to create tables, their fields, and various constraints.
• Each model class maps to a single table in the database.
• Django Model is a subclass of django.db.models.Model and each field of the model class represents a database field (column).

Django settings

• A Django settings file contains all the configuration of your Django installation.
• A settings file is just a Python module with module-level variables.

# setting example
ALLOWED_HOSTS = ['www.example.com']
DEBUG = False
DEFAULT_FROM_EMAIL = 'webmaster@example.com'

Django Migrations

Migration in Django is to make changes to your models

Like deleting, adding a field, etc. into your database schema.

Django Views

• A view is a place where we put our business logic of the application
• The view is a python function that takes a web request and returns a web response
• This response can be the HTML contents of a Web page, or a redirect, or a 404 error

Django Signal

The Django Signals is a strategy to allow decoupled applications to get notified when certain events occur.

There are two key elements in the signals machinery: the senders and the receivers

As the name suggests, the sender is the one responsible to dispatch a signal, and the receiver is the one who will receive this signal and then do something.