setup project directory for Django
----------------------------------
=>Create Parent directory workspace
mkdir Dev

cd Dev
=>Create Virualenv dir
mkdir trydjango
cd trydjango

=>create virualenv in trydjango dir
virtualenv .

=>activate virtualenv
Scripts\activate

=>To see installed versions on virtualenv
pip freeze

=>To see available command lists in virtualenv
django-admin
0utput:
Available subcommands:

[django]
    check
    compilemessages
    createcachetable
    dbshell
    diffsettings
    dumpdata
    flush
    inspectdb
    loaddata
    makemessages
    makemigrations
    migrate
    runserver
    sendtestemail
    shell
    showmigrations
    sqlflush
    sqlmigrate
    sqlsequencereset
    squashmigrations
    startapp
    startproject
    test
    testserver
=>django-admin startproject trydjango .

=>python manage.py runserver

settings.py
===========
stuff like that used to configure entire projuct components in one place.

=>python manage.py makemigrations
=>python manage.py migrate
to make all changes saved/migrated.

Createsuperuser for admin module:
--------------------------------
python manage.py createsuperuser

username: thamma
pwd: thamma123

Create new-App:
---------------
python manage.py startapp products

Connecting to shell:
-------------------
=>python manage.py shell

=>from products.models import Product

=>Product.objects.all()

=>Product.objects.create(title='Title of product',description='description of products',price='1235',summary='Summary of products')

we can add no.of products into database.

Customising model Product:
-------------------------

	title			= models.CharField(max_length=100)
	description 	= models.TextField(blank=True, null=True)
	price 			= models.DecimalField(decimal_places=2, max_digits=1000)
	summary			= models.TextField(blank=False)
	features		= models.BooleanField()
	
	
Here, blank=True referes optional Field, no need to enter any value.
if blank is False, it is mandatory Field.

for all model/db changes you need to run:
python manage.py makemigrations
python manage.py migrate

----------------------------
Creating basic views.

python manage.py startapp pages

views.py:
--------
def home_view(request,*args,**kwargs):
	#return HttpResponse('<H1>Hello World</H1>')
	return render(request, 'home.html',{})

here request is URL page request object and arguments are passed by user request page, {} context dict represents users input parameters

added all views and create template directory and create html files for each view.

Template Inheritance:
--------------------

base.html - is the one to having proto type of all backgroud html views

we have to user tags to extends base.html file to all other html files.

{% extends 'base.html' %}

{% block content %}
your customized template goes here 
{% endblock %}
====================

include html pages:
------------------
We can define short html pages and import them in several pages

navbar.html - contains only navbar options

to include navbar.html we have to use {% include 'navbar.html' %}

Rendering context to HTML pages:
---------------------------------
In case of sending date from view functions to html pages, need to define dict variable(Recomended) or normal variable and pass it in reder function argument.


def about_view(request, *args, **kwargs):
    my_context={
        'title':"This is Context variable of about page",
        'price': 2365.25,
        'name': 'Soap'
    }
    return render(request, 'about.html', my_context)


call variables in HTML files as :

{% block content %}
<h2> This is About page </h2>
{{ title }} </br>
{{ price }}</br>
{{ name }}</br>

{% endblock %}

for loop:
--------
<ul>
{% for item in my_list %}
    <li> {{ forloop.counter}} - {{ item }}</li>
{% endfor %}

conditioning in templates:
{% if name == 'Soap' %}
    <H1>Name is Soap</H1>
{% else %}
    <h2> undefined </h2>
{% endif %}


for more Built in template tags and filters:
https://docs.djangoproject.com/en/2.2/ref/templates/builtins/

------------
render data from Database.

need to define view in product views.py

from .models import product   - will import model from database

obj=Product.objects.all()     - will fetch data from database

we will render obj as context variable to html pages.
-------------
Keep all stuff related to an APP inside of it. it is easy to export an app to other places
---------------

Working with Forms:
==================

easy way:
--------
Create form.py file and 

import forms from django

import model from which you want create form

define class and create meta class for model and it's fields

create a view - import form.py module and create form object with form.py module class name

render form object with newly created HTML file. and create HTML file and call form object to view properties

create url for new view to access Creation Form.
------------------------------------------------