Django Form Validation

Django provides built-in methods to validate form data automatically. Django forms submit only if it contains CSRF tokens. It uses uses a clean and easy approach to validate data.

The is_valid() method is used to perform validation for each field of the form, it is defined in Django Form class. It returns True if data is valid and place all data into a cleaned_data attribute.

Let's see an example that takes user input and validate input as well.

Django Validation Example

This example contains the following files and code.

// models.py

snippet

from django.db import models
class Employee(models.Model):
    eid = models.CharField(max_length=20)
    ename = models.CharField(max_length=100)
    econtact = models.CharField(max_length=15)
    class Meta:
        db_table = "employee"

Now, create a form which contains the below code.

// forms.py

snippet

from django import forms
from myapp.models import Employee

class EmployeeForm(forms.ModelForm):
    class Meta:
        model = Employee
        fields = "__all__"

Instantiate the form

Instantiate the form, check whether request is post or not. It validate the data by using is_valid() method.

//views.py

snippet

def emp(request):
    if request.method == "POST":
        form = EmployeeForm(request.POST)
        if form.is_valid():
            try:
                return redirect('/')
            except:
                pass
    else:
        form = EmployeeForm()
    return render(request,'index.html',{'form':form})

Index template that shows form and errors.

// index.html

snippet

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Index</title>
</head>
<body>
<form method="POST" class="post-form" enctype="multipart/form-data">
        {% csrf_token %}
        {{ form.as_p }}
        <button type="submit" class="save btn btn-default">Save</button>
</form>
</body>
</html>

Start server and access the form.