Django Forms

Django Forms are used to gather input from users, validate that input, and process it, often saving the data to the database. For example, when registering a user, a form collects information like name, email, and password.

Django automatically maps form fields to corresponding HTML input elements. It also handles:

• Preparing data for rendering
• Creating HTML forms
• Processing submitted form data securely

While you can build forms using raw HTML, Django Forms simplify form creation and validation, making your code cleaner and more secure.

Note that all types of work done by forms in Django can be done with advanced HTML stuff, but Django makes it easier and efficient especially the validation part. Once you get hold of forms in Django you will just forget about HTML forms.

Syntax:

Django form fields are defined much like Django model fields:

field_name = forms.FieldType(**options)

Befor creating forms, ensure that a django project and app is already set up, refer to the following article to learn how to do it:

• How to Create a Basic Project using MVT in Django?
• How to Create an App in Django ?

Creating a Simple Django Form

Creating a form in Django is completely similar to creating a model, one needs to specify what fields would exist in the form and of what type. For example, to input, a registration form one might need First Name (CharField), Roll Number (IntegerField), and so on. 

Syntax: 

from django import forms

class FormName(forms.Form):
# each field would be mapped as an input field in HTML
field_name = forms.Field(**options)

To create a form, create a forms.py file in you app folder:

from django import forms

class InputForm(forms.Form):
    first_name = forms.CharField(max_length=200)
    last_name = forms.CharField(max_length=200)
    roll_number = forms.IntegerField(help_text="Enter 6 digit roll number")
    password = forms.CharField(widget=forms.PasswordInput())

Render Django Forms

Django form fields have several built-in methods to ease the work of the developer but sometimes one needs to implement things manually for customizing User Interface(UI). A form comes with 3 in-built methods that can be used to render Django form fields. 

• {{ form.as_table }} will render them as table cells wrapped in <tr> tags
• {{ form.as_p }} will render them wrapped in <p> tags
• {{ form.as_ul }} will render them wrapped in <li> tags

To render this form into a view, move to views.py and create a home_view as below. 

from django.shortcuts import render
from .forms import InputForm

# Create your views here.
def home_view(request):
    context ={}
    context['form']= InputForm()
    return render(request, "home.html", context)

In view, one needs to just create an instance of the form class created above in forms.py. Now let's edit templates > home.html 

<form action = "" method = "post">
    {% csrf_token %}
    {{form }}
    <input type="submit" value=Submit">
</form>

Now, visit http://localhost:8000/

To check how to use the data rendered by Django Forms visit Render Django Form Fields 

Create Django Form from Models

Django ModelForm is a class that is used to directly convert a model into a Django form. If you’re building a database-driven app, chances are you’ll have forms that map closely to Django models. Now when we have our project ready, create a model in geeks/models.py,

# import the standard Django Model
# from built-in library
from django.db import models
  
# declare a new model with a name "GeeksModel"
class GeeksModel(models.Model):
        # fields of the model
    title = models.CharField(max_length = 200)
    description = models.TextField()
    last_modified = models.DateTimeField(auto_now_add = True)
    img = models.ImageField(upload_to = "images/")
  
        # renames the instances of the model
        # with their title name
    def __str__(self):
        return self.title

To create a form directly for this model, dive into geeks/forms.py and Enter the following code:

# import form class from django
from django import forms
 
# import GeeksModel from models.py
from .models import GeeksModel
 
# create a ModelForm
class GeeksForm(forms.ModelForm):
    # specify the name of model to use
    class Meta:
        model = GeeksModel
        fields = "__all__"

Now visit http://127.0.0.1:8000/

Read Next: Python | Form validation using django

Django Forms Data Types and Fields List

The most important part of a form and the only required part is the list of fields it defines. Fields are specified by class attributes. Here is a list of all Form Field types used in Django

Core Field Arguments

Core Field arguments are the arguments given to each field for applying some constraint or imparting a particular characteristic to a particular Field. For example, adding an argument required = False to CharField will enable it to be left blank by the user. Each Field class constructor takes at least these arguments. Some Field classes take additional, field-specific arguments, but the following should always be accepted: