What's beyond the Django Girls tutorial: an introduction to class based views

Transcript

1. What's beyond Django Girls tutorial an introduction to Class Based Views
2. LETICIA PORTELLA /in/leportella @leportella @leleportella leportella.com pizzadedados.com
3. A tutorial to teach people to develop using Django. Once you've finished the tutorial, you will have a small working web application: your own blog. https://tutorial.djangogirls.org What’s the tutorial?
4. Django 101 Request: /welcome Response
5. Django 101 Request: /welcome Response from django.shortcuts import render def welcome(request): return render(request, 'welcome.html')
6. Django 102 - Listing books Request: /mybooks Response from django.shortcuts import render from .models import Book def get_books_list(request): books = Book.objects.all() return render(request, 'my-books.html', {'object_list': books}) Get all books!
7. Django 102 - Listing books
8. Django 103 - Get specific book Request: /mybooks/1 Response Book 1: A game of thrones from django.http import Http404 from django.shortcuts import render from .models import Book def get_book_by_id(request, pk): try: book = Book.objects.get(id=pk) except Book.DoesNotExist: raise Http404("Book does not exist") return render(request, 'my-book-detail.html', {'object': book})
9. Django 104 - Update book from django.http import Http404 from django.shortcuts import redirect, render from .forms import BookForm from .models import Book def edit_book(request, pk): try: book = Book.objects.get(id=pk) except Book.DoesNotExist: raise Http404("Book does not exist") if request.method == 'GET': form = BookForm(instance=book) return render(request, 'my-book-edit.html', {'form': form, 'object': book}) if request.method == 'POST': book = Book.objects.get(id=pk) form = BookForm(request.POST, instance=book) if form.is_valid(): form.save() return redirect('/old/my-books')
10. Django 104 - Update book from django.http import Http404 from django.shortcuts import redirect, render from .forms import BookForm from .models import Book def edit_book(request, pk): try: book = Book.objects.get(id=pk) except Book.DoesNotExist: raise Http404("Book does not exist") if request.method == 'GET': form = BookForm(instance=book) return render(request, 'my-book-edit.html', {'form': form, 'object': book}) if request.method == 'POST': book = Book.objects.get(id=pk) form = BookForm(request.POST, instance=book) if form.is_valid(): form.save() return redirect('/old/my-books') And we didn’t treat all cases!
11. That feeling…
12. That feeling…
13. Class-based views provide an alternative way to implement views as Python objects instead of functions. Class Based Views! • Organization of code • Mixins (multiple inheritance) to make use of reusable components.
14. Django 201 Request: /welcome Response from django.views.generic import TemplateView class WelcomeView(TemplateView): template_name = 'welcome.html'
15. Django 201 Request: /welcome Response from django.views.generic import TemplateView class WelcomeView(TemplateView): template_name = 'welcome.html'
16. Django 202 - Listing books from django.views.generic import ListView from .models import Book class BooksView(ListView): model = Book template_name = 'my-books.html'
17. Django 202 - Listing books from django.views.generic import ListView from .models import Book class BooksView(ListView): model = Book template_name = 'my-books.html' from django.shortcuts import render from .models import Book def get_books_list(request): books = Book.objects.all() return render(request, 'my-books.html', {'object_list': books})
18. Django 203 - Update book from django.views.generic import UpdateView from .forms import BookForm from .models import Book class BookUpdateView(UpdateView): model = Book template_name = 'my-book-edit.html' form_class = BookForm success_url = '/my-books'
19. Django 203 - Update book from django.views.generic import UpdateView from .forms import BookForm from .models import Book class BookUpdateView(UpdateView): model = Book template_name = 'my-book-edit.html' form_class = BookForm success_url = '/my-books' 13 lines vs 4 lines!
20. Django 204 - Get specific book from django.views.generic import DetailView from .models import Book class BookDetailByIdView(DetailView): model = Book template_name = 'my-book-detail.html'
21. Django 204 - Get specific book from django.views.generic import DetailView from .models import Book class BookDetailByIdView(DetailView): model = Book template_name = 'my-book-detail.html' from django.http import Http404 from django.shortcuts import render from .models import Book def get_book_by_id(request, pk): try: book = Book.objects.get(id=pk) except Book.DoesNotExist: raise Http404("Book does not exist") return render(request, 'my-book-detail.html', {'object': book})
22. But what if we want different behaviour? All base classes have a specific behaviour. In the DetailView the default is look for id. But what if we want to look for a different code?
23. But what if we want different behaviour? from django.views.generic import DetailView from .models import Book class BookDetailByCodeView(DetailView): model = Book template_name = 'my-book-detail.html' def get_object(self): return Book.objects.get(code=self.kwargs['code']) GET /mybooks/123abc456
24. But what if we want different behaviour? from django.views.generic import DetailView from .models import Book class BookDetailByCodeView(DetailView): model = Book template_name = 'my-book-detail.html' def get_object(self): return Book.objects.get(code=self.kwargs['code']) GET /mybooks/123abc456 # urls.py urlpatterns = [ url(r’^mybooks/(?P<code>[-\w]+)', views.BookDetailByCodeView.as_view()), ]
25. Now, you may ask… How did you know which method to change?
26. ccbv.co.uk <3
27. ccbv.co.uk <3
28. ccbv.co.uk <3
29. ccbv.co.uk <3
30. Anything else?
31. Anything else? Yes! Authentication!
32. Authentication is only one line away! from django.contrib.auth.mixins import LoginRequiredMixin from django.views.generic import DetailView from .models import Book class BookDetailView(LoginRequiredMixin, DetailView): model = Book template_name = 'my-book-detail.html' login_url = '/login'
33. Wanna see the real code? https://github.com/leportella/class-based-views-example https://leportella.com/english/2017/11/24/classe-based- views-on-django.html or http://bit.ly/classbasedviews
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35. LETICIA PORTELLA /in/leportella @leportella @leleportella leportella.com pizzadedados.com