Django DeleteView

Summary: in this tutorial, you’ll learn how to use the Django DeleteView class to define a class-based view that deletes an existing object.

This tutorial begins where the Django UpdateView tutorial left off.

Create a Django DeleteView class

The Django DeleteView class allows you to define a class-based view that displays a confirmation page and deletes an existing object.

If the HTTP request method is GET, the DeleteView view will display the confirmation page. However, if the request is POST, the DeleteView view will delete the object.

To use the DeleteView class, you define a class that inherits from it and add attributes and methods to override the default behaviors.

For example, the following defines a TaskDelete class that deletes a task for the Todo app:

#...
from django.views.generic.edit import DeleteView, CreateView, UpdateView
from django.contrib import messages
from django.urls import reverse_lazy

from .models import Task

class TaskDelete(DeleteView):
    model = Task
    context_object_name = 'task'
    success_url = reverse_lazy('tasks')
    
    def form_valid(self, form):
        messages.success(self.request, "The task was deleted successfully.")
        return super(TaskDelete,self).form_valid(form)

#...Code language: Python (python)

In this example, we define the TaskDelete class that is a subclass of the DeleteView class. The TaskDelete class has the following attributes:

• model specifies the class of the model (Task) that will be deleted.
• context_object_name specifies the object name that will be passed to the template. By default, the DeleteView class uses the object as the name. However, you can override the name using the context_object_name attribute.
• success_url is the URL that will be redirected to once the object is deleted successfully.
• form_valid() method is called once the object is deleted successfully. In this example, we create a flash message.

By default, the DeleteView class uses the task_confirmation_delete.html template if you don’t specify it explicitly.

Creating task_confirm_delete.html template

Create a new file task_confirm_delete.html template in the templates/todo app with the following code:

{%extends 'base.html'%}

{%block content%}
<div class="center">
	<form method="post" class="card">
		{% csrf_token %}
		<h2>Delete Task</h2>
		<p>Are you sure that you want to delete "{{task}}"?</p>
		<p class="form-buttons">
			<input type="submit" class="btn btn-primary" value="Delete">
			<a href="{% url 'tasks'%}" class="btn btn-outline">Cancel</a>
		</p>
	</form>
</div>

{%endblock content%}Code language: HTML, XML (xml)

The task_confirm_delete.html extends the base.html template and contains a form that deletes a task.

Defining a route

Define a new route in the urls.py that maps a URL that deletes a task with the result of the as_view() method of the TaskDelete view class:

from django.urls import path
from .views import (
    home, 
    TaskList, 
    TaskDetail, 
    TaskCreate, 
    TaskUpdate,
    TaskDelete
)


urlpatterns = [
    path('', home, name='home'),
    path('tasks/', TaskList.as_view(),name='tasks'),
    path('task/<int:pk>/', TaskDetail.as_view(),name='task'),
    path('task/create/', TaskCreate.as_view(),name='task-create'),
    path('task/update/<int:pk>/', TaskUpdate.as_view(),name='task-update'),
    path('task/delete/<int:pk>/', TaskDelete.as_view(),name='task-delete'),
]Code language: Python (python)

Including a link to delete a task

Modify the task_list.html template to add a link that deletes a task to each task on the task list:

{%extends 'base.html'%}

{%block content%}

<div class="center">
	<h2>My Todo List</h2>
	{% if tasks %}
	<ul class="tasks">
		{% for task in tasks %}
			<li><a href="{% url 'task' task.id %}" class="{% if task.completed%}completed{%endif%}">{{ task.title }}</a> 
				 <div  class="task-controls">
				 	<a href="{%url 'task-delete' task.id %}"><i class="bi bi-trash"></i> </a>
					<a href="{%url 'task-update' task.id %}"><i class="bi bi-pencil-square"></i></a>
		         </div>
		    </li>
		{% endfor %}
	{% else %}
		<p>🎉 Yay, you have no pending tasks! <a href="{%url 'task-create'%}">Create Task</a></p>
	{% endif %}
	</ul>
</div>
{%endblock content%}
Code language: HTML, XML (xml)

If you click the delete button to delete a task on the list, you’ll get the following delete confirmation page:

Click the Delete button will delete the task from the database and redirect it back to the task list:

You can download the final code for this Django DeleteView tutorial here.

Summary

• Use Django DeleteView class to define a class-based view that deletes an existing object.