fdp

1. Web Application using Django
(Session Management)
Presented by
Mr.B.Muthukrishna Vinayagam, AP-CSE

2. Cookies
• HTTP’s statelessness poses a huge problem for Web developers, and thus cookies
were born. A cookie is a small piece of information that browsers store on behalf of
Web servers.
• COOKIES is a special attribute of request, and its value is the name of the cookie
from which you want to read data
– Using request.COOKIES[]
• Basic syntax to access a class parameter as: request.COOKIES[‘cookie_name’]
• Using Directmethod: request.COOKIES.get(key,value)
• Using response object with following function to set and delete cookie.
– set_cookie() to create cookies, we can also delete cookies using a similar function, delete_cookie()

4. Views.py
def chk(request):
count=request.COOKIES.get('count',0)
tc=int(count)+1
response=render(request,"testck.html",{'count':tc})
response.set_cookie('count',tc)
return response
def dck(request):
response = HttpResponse("Deleting the cookie which is set")
response.delete_cookie('count','Updated Successfully')
return response

5. from django.urls import reverse
return res
def reset(request):
res=HttpResponse("cookies deleted <a
href='{}'>reload</a>".format(reverse('index')))
res.delete_cookie('count','Updated
Successfully')
return res

6. testck.html
<h1> User Visit(s) {{count}}</h1>
urls.py
from django.contrib import admin
from django.urls import path
from APP import views
urlpatterns = [
path('admin/', admin.site.urls),
path("chk",views.chk,name="chk"),
path("dck",views.dck,name="dck"),]
]

7. Session
Sessions are the mechanism used by Django (and most of the
Internet) for keeping track of the "state" between the site and a
particular browser.
The session is a semi-permanent and two-way communication
between the server and the browser.

8. Syntax
# Get a session value, setting a default if it is not present (0)
count= request.session.get(' count ',0)
# Set a session value
request.session[' count '] =0
# Delete a session value
del request.session[' count ']

9. Views.py
def chk(request):
count=request.session.get('count',0)
tc=int(count)+1
response=render(request,"testck.html",{'count':tc})
return response
def dck(request):
del request.session['count']
response = HttpResponse("Deleting the session key which is set")
return response

10. testck.html
<h1> User Visit(s) {{count}}</h1>
urls.py
from django.contrib import admin
from django.urls import path
from APP import views
urlpatterns = [
path('admin/', admin.site.urls),
path("chk",views.chk,name="chk"),
path("dck",views.dck,name="dck"),]
]

11. Session Example2
(logging and logout with Session)
forms.py
from django.contrib.auth.models import User
from django.contrib.auth.forms import UserCreationForm
class NewUserForm(UserCreationForm):
class Meta:
model=User
fields=['username','email','password1','password2']

12. Views.py
from django.shortcuts import render,HttpResponse,redirect
from django.contrib.auth import authenticate,login,logout
from.forms import *
def signup(request):
if request.method=='POST':
form = NewUserForm(request.POST)
if form.is_valid():
form.save()
return redirect('login')
else:
form = NewUserForm()
return render(request, 'signup.html', {'form': form })

13. def loginpage(request):
if request.method=='POST':
username=request.POST.get('username')
pass1=request.POST.get('password')
user=authenticate(request,username=username,password=pass1)
if user is not None:
login(request,user)
request.session["uname"] = username
return redirect('home')
else:
return HttpResponse ("Username or Password is incorrect!!!")
return render (request,'login.html')

14. def home(request):
uname =request.session["uname"]
return render (request,'home.html',{'uname': uname})
def logoutpage(request):
del request.session["uname"]
logout(request)
return redirect('login')

15. templates
signup.html
<form action="" method="post">
{%csrf_token %}
{{form.as_p}}
<input type="submit" value="New User"/>
</form>
<a href="{% url 'login' %}" >signup</a>

16. login.html
<form action="" method="post">
{%csrf_token %}
<input type="text" name="username" id="username" placeholder="username"/><br/>
<input type="password" name="password" id="password" placeholder="password"/><br/
<input type="submit" value="Login"/>
</form>
<a href="{% url 'signup' %}" >Signup </a>
home.html
<body>
<h1>Home Page</h1>
<h2>Welcome! {{uname}} </h2>
<a href="{% url 'logout' %}">Logout</a>
</body>

17. urls.py
from django.contrib import admin
from django.urls import path
from myapp.views import *
urlpatterns = [
path('admin/', admin.site.urls),
path('home/',home,name='home'),
path('',signup,name='signup'),
path('login/',loginpage,name='login'),
path('logout/',logoutpage,name='logout')
]

18. mail
from django.core.mail import send_mail
send_mail(
"Subject here",
"Here is the message.",
"from@example.com",
["to@example.com"],
fail_silently=False,
)

19. settings.py
EMAIL_BACKEND =
'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST = 'smtp-mail.outlook.com’
#smtp.gmail.com
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = 'xxxx'
EMAIL_HOST_PASSWORD = 'xxxxxx' #app password

20. Include Bootstrap
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width,
initial-scale=1.0">
<title>Index web page</title>
<link rel="stylesheet" href="{% static 'cssbootstrap.min.css'
%}">
</head>
<body>
<script src="{% static 'jsbootstrap.bundle.min.js'
%}"></script>
<nav class="navbar navbar-expand-sm bg-dark navbar-dark
sticky-top">
<div class="container-fluid">
<a class="navbar-brand" href="index.html">Logo</a>
<button class="navbar-toggler" type="button"
data-bs-toggle="collapse" data-bs-target="#id">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse bg-dark" id="id">
<ul class="navbar-nav">
<li class="nav-item">
<a href="{% url 'reset' %}" class="nav-link">Reset</a>
</li>
{%if uname%}
<li class="nav-item">
<a href="{% url 'logout'%}" class="nav-link">Logout</a>
</li>
{% else%}
<li class="nav-item">
<a href="{% url 'login' %}" class="nav-link">Login</a>
</li>
<li class="nav-item">
<a href="{% url 'signup' %}" class="nav-link">SignUp</a>
</li>
{%endif%}
</ul>
</div>
</div>
</nav>
</body> </html>

21. Settings.py
import os
STATIC_URL = '/static/'
STATICFILES_DIRS = [(os.path.join(BASE_DIR, 'static'))]
STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')
MEDIA_URL = '/media/'
MEDIA_ROOT = os.path.join(BASE_DIR, 'media/')
Urls.py:
urlpatterns +=
static(settings.STATIC_URL,document_root=settings.STATIC_ROOT)
urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)

22. Thank you