How to update a view function based on views in Django

Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. Built by experienced developers, Django takes care of much of the hassle of web development so you can focus on writing your app without needing to reinvent the wheel. Django is free and open source.

In this shot, we will be looking at how to update a particular instance with the Django function-based view. Update view must display the old data in the form, let the user only update the data from there, and return the updated data.

Installation

Run the following commands:

pip is a package manager for Python packages.

pip install pipenv
pipenv shell
pipenv install django

Then:

django-admin startproject crud ./
python manage.py startapp codebase

python manage.py migrate
python manage.py runserver

Go to settings.py and add the following.

settings.py helps register your app and packages that are being installed and even writes rules.

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'codebase'
]

In the codebase app folder, go to models.py.

models.py

This file is responsible for creating the model for the database.

from django.db import models
from django.urls import reverse
class CRUD(models.Model):
    name = models.CharField(max_length=30)
    age = models.IntegerField()
    level = models.CharField(max_length=30)
    date = models.DateTimeField(auto_now_add=True)
    #display the data with name
    def __str__(self):
        return self.name

admin.py

In this file, we import and register our created model. By doing so, we can see the model when logged in as an admin.

from django.contrib import admin
from .models import CRUD
admin.site.register(CRUD)

Create a file and name it forms.py.

The forms file is responsible for creating Django forms, which are like HTML forms, but dynamic.

forms.py

from django import forms
from .models import CRUD
class CRUDFORM(forms.ModelForm):
    name = forms.CharField(widget=forms.TextInput(attrs={
        "class": "form-control",
        "placeholder": "name"
    }))
    age= forms.CharField(widget=forms.TextInput(attrs={
        'type': "number",
        "class": "form-control",
        "placeholder": "age"
    }))
    
    level = forms.CharField(widget=forms.TextInput(attrs={
        "class": "form-control",
        "placeholder": "level"
    }))
    class Meta:
        model = CRUD
        fields = [
            'name', 'age','level'
        ]

views.py

This file is used to create functions or classes that visualize how a route will operate.

from django.shortcuts import redirect, render, get_object_or_404
from .models import CRUD
from .forms import CRUDFORM
def home(request):
    queryset = CRUD.objects.all().order_by('-date')
    context = {
        'queryset': queryset
    }
    return render(request, 'app/base.html', context)
def create(request):
    form = CRUDFORM(request.POST or None)
    if request.method == "POST":
        if form.is_valid():
            form.save()
            return redirect ('home')
    context = {
        "form":form
    }
    return render(request, 'app/createform.html', context)
def update(request, id):                                         
    data = get_object_or_404(CRUD, id=id)
    form = CRUDFORM(instance=data)                                                               
    if request.method == "POST":
        form = CRUDFORM(request.POST, instance=data)
        if form.is_valid():
            form.save()
            return redirect ('home')
    context = {
        "form":form
    }
    return render(request, 'app/createform.html', context)

In the codebase app, create a folder and name it templates. Inside the templates folder, create another folder and name it app. Then, inside the app folder, create ‘base.html’ and 'createform.html' files.

base.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Crud</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-giJF6kkoqNQ00vy+HMDP7azOuL0xtbfIcaT9wjKHr8RbDVddVHyTfAAsrekwKmP1" crossorigin="anonymous">
</head>
<body>
    
    <div class="container mt-3">
      <!-- this code block is used to used to create a url link -->
      <a href="{% url 'create'%}" >link to create a form</a>
      <hr>
      <!-- this code block is used for looping the data in the database -->
      {% for data in queryset %}
      <div class="list-group mb-3">
        <!-- this code block is used to used to create a url link -->
        <a href="{% url 'update' data.id %}" >update</a>
        <a href="#" class="list-group-item list-group-item-action">Name: {{data.name}}</a>
        <a href="#" class="list-group-item list-group-item-action">Age: {{data.age}}</a>
        <a href="#" class="list-group-item list-group-item-action">Level: {{data.level}}</a>
      </div>
      {% endfor %}
      <hr>  
    </div>
</body>
</html>

createform.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Crud</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-giJF6kkoqNQ00vy+HMDP7azOuL0xtbfIcaT9wjKHr8RbDVddVHyTfAAsrekwKmP1" crossorigin="anonymous">
</head>
<body>
    <div class="container mt-5">
        <form method="POST" action="">
            <!-- for csrf token -->
            {% csrf_token %}
            <div class="form-group mb-3">
                <!-- double curly braces is used to display data from the database -->
                {{form.name}}
                {{form.name.errors}}
            </div>
            <div class="form-group mb-3">
                {{form.age}}
                {{form.age.errors}}
            </div>
            <div class="form-group mb-3">
                {{form.level}}
                {{form.level.errors}}
            </div>
            <input type="submit" class="btn btn-outline-success" >
            
        </form>
    </div>
</body>

In the urls.py file in the crud folder, in the urls.py file, add the code below.

urls.py

from django.contrib import admin
from django.urls import path, include
urlpatterns = [
    path('admin/', admin.site.urls),
    # including the codebase urls.py file
    path('', include('codebase.urls'))
]

Then, in the codebase folder, create a file and name it urls.py.

urls.py is responsible for creating different routes.

urls.py

from django.urls import path
from .views import home, create,update
urlpatterns = [
    path('',home, name="home" ),
    path('create/', create, name="create"),
    path('update/<str:id>/', update, name="update"),
]

Run the following commands:

python manage.py makemigrations

python manage.py migrate

In case you want to create a super-user, run the following command:

python manage.py createsuperuser

After that, run:

python manage.py runserver

Then, go to http://127.0.0.1:8000/admin and login in order to access the admin panel or http://127.0.0.1:8000/ to access the homepage.

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