How to do Django form validation
Njoku Ifeanyi GeraldIn this shot, we’ll learn to do Django form validation. Django automatically has built-in methods that validate the data from the form.
Note: Django forms are similar to advanced
forms, except that they are more Python-oriented in nature. HTML HyperText Markup Language
Code
First, install Django by using the following commands:
pip install pipenv
pipenv shell
pipenv install django
Next, create the Django project:
django-admin startproject DjangoForm ./
python manage.py startapp codebase
python manage.py migrate
python manage.py runserver
Configurations
First, add the project name to the settings.py file, as shown below:
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'codebase'
]Note:
codebaseshould be replaced by the name of your Django project.
Next, in the codebase application folder, go to the models.py file and create the following model:
from django.db import models # model named Post class CommentModel(models.Model): name = models.CharField( max_length = 100, blank = False,null = False) comment = models.TextField(blank = False, null = False) time = models.DateTimeField(auto_now_add = True)
Once our model is created, register it in the admin.py file, as shown below:
from django.contrib import admin from .models import CommentModel admin.site.register(CommentModel)
Create the form
After completing the configuration, create a file for the form. In our case, the file is named forms.py.
from logging import PlaceHolder
from django import forms
from .models import CommentModel
class CommentForm(forms.ModelForm):
name = forms.CharField(widget=forms.TextInput(attrs={
'class': 'form-control',
'placeholder': 'name'
}))
comment = forms.CharField(widget=forms.Textarea(attrs={
'class': 'form-control',
'placeholder': 'comment section'
}))
class Meta:
model = CommentModel
fields = ['name', 'comment']
def clean(self):
# data is feteched using the super function of django
super(CommentForm, self).clean()
name = self.cleaned_data.get('name')
comment = self.cleaned_data.get('comment')
if len(name) < 3:
self._errors['name'] = self.error_class([
'3 characters and more is required for this field'
])
if len(comment) < 4:
self._errors['comment'] = self.error_class([
'comments should be more than 4 characters'
])
return self.cleaned_data
Now, create a view for our project with the form created. The corresponding views.py file is shown below:
from django.shortcuts import render, redirect
from .models import CommentModel
from .forms import CommentForm
def home(request):
form = CommentForm(request.POST or None)
if request.method == 'POST':
if form.is_valid():
form.save()
return redirect ('home')
context = {
'form': form
}
return render(request, 'app/home.html', context)- Next, in the
codebaseapp folder, create a folder and name ittemplates. - Inside the
templatesfolder, create another folder and name itapp. - Inside the
appfolder, create thehome.htmlfile as shown below:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet"
integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3"
crossorigin="anonymous">
</head>
<body class="container mt-4">
<form method="POST" action="">
{% csrf_token %}
<div class="form-group mb-3">
{{form.name}}
{{form.name.errors}}
</div>
<div class="form-group mb-3">
{{form.comment}}
{{form.comment.errors}}
</div>
<button class="btn btn-outline-success">Submit</button>
</form>
</body>
</html>Set route URLs
Within the main folder, in the urls.py file, add a route to the URLs of the codebase app, as shown below:
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'))
]Finally, in the codebase folder, create a file called urls.py that contains the route to the home view:
from django.urls import path
#importing home function from views.py
from .views import home
urlpatterns = [
path('', home, name='home'),
]
Access form
Once the entry process is complete, 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
Once we’re ready to access the newly created form, run this command:
python manage.py runserver
The command above starts our server on the URL: http://127.0.0.1:8000/admin, which can be accessed now.
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