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POWhat is the advantage of Class-Based views?
 

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    <p>I read today that Django 1.3 alpha is shipping, and the most touted new feature is the introduction of <a href="http://docs.djangoproject.com/en/dev/releases/1.3-alpha-1/#class-based-views">class-based views</a>.<br> I've read the <a href="http://docs.djangoproject.com/en/dev/topics/class-based-views/">relevant documentation</a>, but I find difficult to see the <em>big advantage™</em> that I could get by using them, so I'm asking here for some help in understanding them.<br> Let's take an <a href="http://docs.djangoproject.com/en/dev/topics/class-based-views/#viewing-subsets-of-objects">advanced example</a> from the documentation.</p> <h2>urls.py</h2> <pre><code>from books.views import PublisherBookListView urlpatterns = patterns('', (r'^books/(\w+)/$', PublisherBookListView.as_view()), ) </code></pre> <h2>views.py</h2> <pre><code>from django.shortcuts import get_object_or_404 from django.views.generic import ListView from books.models import Book, Publisher class PublisherBookListView(ListView): context_object_name = "book_list" template_name = "books/books_by_publisher.html", def get_queryset(self): self.publisher = get_object_or_404(Publisher, name__iexact=self.args[0]) return Book.objects.filter(publisher=self.publisher) def get_context_data(self, **kwargs): # Call the base implementation first to get a context context = super(PublisherBookListView, self).get_context_data(**kwargs) # Add in the publisher context['publisher'] = self.publisher return context </code></pre> <p>And now let's compare it to a “plain-old-views” solution, made by myself in 5 minutes for this question (I apologize for any error you may find in it).</p> <h2>urls.py</h2> <pre><code>urlpatterns = patterns('books.views', url(r'^books/(\w+)/$', 'publisher_books_list', name="publisher_books_list"), ) </code></pre> <h2>views.py</h2> <pre><code>from django.shortcuts import get_object_or_404 from books.models import Book, Publisher def publisher_books_list(request, publisher_name): publisher = get_object_or_404(Publisher, name__iexact=publisher_name) book_list = Book.objects.filter(publisher=publisher) return render_to_response('books/books_by_publisher.html', { "book_list": book_list, "publisher": publisher, }, context_instance=RequestContext(request)) </code></pre> <p>The second version to me looks:</p> <ul> <li>Equivalent in functionality</li> <li>A lot more readable (<code>self.args[0]</code>? awful!)</li> <li>Shorter</li> <li>Not less DRY-compliant</li> </ul> <p>Is there something big I'm missing? Why should I use them? Are those on the documentation? If so then what would be the ideal use case? Are <em>mixins</em> that useful?</p> <p>Thanks in advance to anybody who contributes!</p> <p><strong>P.S.</strong> for those who might wonder, I was never enthralled by generic views as well: as soon as I needed some advanced functionality, they became no shorter than regular views.</p>
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    1. COYeah I'm not seeing the big advantage either. Would love to see a big answer on this.
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    2. COCompletely agree. I'm especially disgusted by self.args[0] or self.kwargs['slug']. It's now also a lot harder to provide default values for url parameters, like this: def publisher_books_list(request, publisher_name='Herbert')
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