CustomLoginView

LoginView

Today, we are excited to traverse the abstractions used in the following CustomLoginView & LoginView classes:

class CustomLoginView(LoginView):
    """This view renders our custom login form"""
    form_class = CustomLoginForm
    template_name = 'account/login.html'

What is it?

Django is a framework, which means it offers built-in reusable components. One of these is LoginView. In our case, we're enhancing this by inheriting from it via the django-allauth package, sourced from the allauth.account.views module:

from allauth.account.views import LoginView

• This additional layer of functionality allows for features like social authentication and email verification.

That said, you'll need to install the package beforehand:

pip install django-allauth

If you choose not to install it, you will retain the core functionality described below, minus the additional features provided by allauth.

Quote

The process is simple: install django-allauth, inherit from its LoginView, and override the default attributes to customize it according to your needs.

What Does it Do?

LoginView enables code reusability, eliminating the need to "reinvent the wheel." You'd otherwise have to build your own login mechanism, which would require significant effort in both logic and security—elements that have already been taken care of.

You have access to methods like get(), post(), get_form_class(), form_valid(), get_context_data(), and get_success_url().

The form_class attribute (another name for a variable but in OOP terms) specifies the form we intend to use. Likewise, template_name designates the template where our form, HTML, JavaScript, and CSS will be rendered. Both form_class and template_name are attributes of the class.

You can also extend the context to include more information by overriding get_context_data():

# Inside our CustomLoginView class:

def get_context_data(self, **kwargs):
    context = super().get_context_data(**kwargs)
    context['extra_info'] = 'This is some extra information.'
    return context

How Does It Work?

1. Create a Subclass: Inherit from the imported LoginView:

from allauth.account.views import LoginView

class CustomLoginView(LoginView):
    # code pending

1. Specify Custom Functionality: Override LoginView's default attributes with your custom configurations:

from .forms import CustomLoginForm

class CustomLoginView(LoginView):
    form_class = CustomLoginForm

Note how we're importing a custom form, thus overriding either the package's or Django's default form.

1. Specify the Template:

class CustomLoginView(LoginView):
    """This view renders our custom login form"""
    form_class = CustomLoginForm
    template_name = 'account/login.html'

This allows you to render your form within a customizable template.

Insights & Clean Code

Insights

from django.contrib import messages

class CustomLoginView(LoginView):
    form_class = CustomLoginForm
    template_name = 'account/login.html'

    def form_valid(self, form):
        # Call the parent class's form_valid method and store its return value
        response = super().form_valid(form)
        # Custom logic
        username = form.cleaned_data.get('username')
        messages.success(self.request, f'Welcome, {username}!')
        # Return the HttpResponse object
        return response

    def form_invalid(self, form):
        messages.error(self.request, 'Login failed. Please try again.')
        # Call the parent class's form_invalid method and return its value
        return super().form_invalid(form)

Here, response = super().form_valid(form) performs the following functions:

1. super(): This returns a temporary object of the superclass, allowing you to call its methods.
2. .form_valid(form): This calls the form_valid method of the superclass. In Django, this method usually handles what to do with a valid form, such as saving a model object.
3. response =: This stores the result of super().form_valid(form)—often an HttpResponse object like a redirect—in the variable response.

The form argument passed into form_valid and form_invalid is an instance of CustomLoginForm, as specified by form_class.

The cleaned_data object is created after form validation upon submission. You can then use .get() to retrieve specific key-value pairs.

Clean Code

from django.contrib import messages
from allauth.account.views import LoginView

class CustomLoginView(LoginView):
    form_class = CustomLoginForm
    template_name = 'account/login.html'

    def form_valid(self, form):
        response = super().form_valid(form)
        username = form.cleaned_data.get('username')
        messages.success(self.request, f'Welcome, {username}!')
        return response

    def form_invalid(self, form):
        messages.error(self.request, 'Login failed. Please try again.')
        return super().form_invalid(form)