How to use CreateView with ModelForm

Question

I get an error in my AuthorCreateForm class when submitting my form. NameError self not defined

How to use CreateForm?

I created a class in the file Author.py

from django.views.generic import TemplateView, ListView, CreateView from books.models import Author, Publisher, Book from books.forms import AuthorForm class AuthorCreateView(CreateView): objAuthorForm = AuthorForm(self.request.POST) if(objAuthorForm.save()): success = "Form saved!" else: error = "There was an error!" 

and I have an html template that sends / Author / Create

and I have the following line in my urls.py

 ('^authors/create/$', Author.AuthorCreateView.as_view()), 

I submit the form at this URL

 ('^authors/new/$', TemplateView.as_view(template_name="author_new.html")), 

I find class-based views confusing, does anyone have a good tutorial on how to use it for CRUD operations?

thank

Answer 1

You have a python error - self not defined. self usually refers to the class instance itself in class methods.

In any case, I agree, this brand spanks a new one and is not documented. I think that looking at the source is absolutely key at this point.

To get comfortable with class-based views, I would start by subclassing django.views.generic.base.View , which implements only a few methods, namely an attempt to call a class function based on the request method (post, get, head, - look at source).

For example, here is the first step to replace view functions with new view classes:

 class MyClassBasedView(View): def get(self, request): # behave exactly like old style views # except this is called only on get request return http.HttpResponse("Get") def post(self, request): return http.HttpResponse("Post") (r'^foobar/$', MyClassBasedView.as_view()) 

Back to your specific question:

All TemplateView.as_view() does the visualization of the template - CreateView is a combination of several other classes that handle ModelForms and template rendering ( TemplateView ).

So, for a very simple example, look at the documents for which the mixins class is used by CreateView .

We see that it implements TemplateResponseMixin , ModelFormMixin and ProcessFormView , each of which contains a list of methods for these classes.

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The easiest CreateView

At the most basic level, provide the CreateView ModelFormMixin model or custom ModelForm class as described here.

Your CreateView class will look something like this:

 class AuthorCreateView(CreateView): form_class = AuthorForm template_name = 'author_new.html' success_url = 'success' 

Given these three basic attributes, enter them in your URLs.

 ('^authors/create/$', Author.AuthorCreateView.as_view()), 

Display the page and you will see that your ModelForm is passed to the template as form , processing the form validation step (passing to request.POST / re-render if it is invalid), and also calls form.save() and redirects to success_url .

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Start overriding class methods

To customize the behavior, start overriding the methods documented for mixins .

Remember that you just need to return the HttpResponse from one of these methods, like any regular view function.

An example override of form_invalid documented in ModelFormMixin :

 class AuthorCreateView(CreateView): form_class = AuthorForm template_name = 'author_new.html' success_url = 'success' def form_invalid(self, form): return http.HttpResponse("form is invalid.. this is just an HttpResponse object") 

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This overriding method starts extremely useful as your forms become more advanced and ultimately allow you to create huge forms with a few lines of code, overriding only what you need.

Suppose you want to pass your custom form parameters, such as a request object (very common if you need access to the user on the form): you just need to override get_form_kwargs .

 class MyFormView(FormView): def get_form_kwargs(self): # pass "user" keyword argument with the current user to your form kwargs = super(MyFormView, self).get_form_kwargs() kwargs['user'] = self.request.user return kwargs 

Class-based views are a prime example of the use of the intellectual class. This gave me a great introduction to creating my own mixes for views and python classes in general. It saves countless hours.

Wow it worked out. Thinking it started as a simple document comment url :) Hope this helps!