Django Model Forms Example

The Django documentation on Model Forms is thorough, but sometimes you want a simple example to explain the concept.   Here's one:

Model forms are used for the majority of forms in Django.  They're forms based on a model.  

Model on which the ModelForm is based:

class notification(models.Model):

    report_type = models.ForeignKey( 'report_type')

    event_type = models.ForeignKey( 'event_type')

    client_type = models.ForeignKey( 'client_type')

    email_addresses = models.TextField( 'Email Addresses (; separated)', null=True , max_length=500)

ModelForm:

from django.forms import ModelForm

from myapp.models import notification

from django.contrib.auth.models import User

from django.db.models import Q

from django.core.exceptions import ValidationError

import logging

log = logging.getLogger(__name__)

   

class notificationForm(ModelForm):   

    class Meta:

        model = Notification

    def clean_email_addresses(self):

        # check the email addresses are all for a registered user

        emails = self.cleaned_data['email_addresses']

        emaillist = emails.split( ";")

        if emaillist is not None:

            for e in emaillist:

                users = User.objects.filter(Q(email=e))

                if not users:

                    raise ValidationError( 'Each email address entered must be for a registered user of X-GenCA')

        return emails

View using the ModelForm:

# Create your views here.

from notification.forms import notificatioForm

from myapp.models import Notification

from django.shortcuts import redirect, render

from django.contrib.auth.decorators import login_required

import logging

log = logging.getLogger(__name__)

#command line debugging:

#import pdb; pdb.set_trace()

@login_required

def create_notification(request, template_name='notification/save.html' ):

    form = notificationForm(request.POST or None)

    if form.is_valid():

        form.save()

        return redirect( '/')

   

    return render(request, template_name, {'form':form,'notification' :Notification})

Template (save.html):

{% extends "base.html" %}

<h1 align="center">Create Notification</h1>

<form method="post" action= ".">

{% csrf_token %}

<div style="text-align: center;">

    {{ form.as_p }}

    <input type="submit" value= "Submit Form"/>

    </div>

</form>

URL pointing to View:

url(r'^create/$', views.create_notification), 

 

 

 

 The clean methods in the ModelForm can be used to add any business logic you require to validate the fields.  In the example above it checks the email addresses are those for registered users of the system.