python / intermediate
Snippet
Django Class-Based Views with Mixin Pattern
Class-Based Views (CBVs) in Django leverage Python's multiple inheritance to compose functionality through Mixins. LoginRequiredMixin from django.contrib.auth.mixins ensures only authenticated users access the view. Custom mixins like BookFormMixin can inject additional context or modify form handling. The order matters: Django reads Mixins right-to-left, so LoginRequiredMixin is checked first. CBVs separate concerns: get() handles GET requests, post() handles POST, while ListView and CreateView provide built-in pagination and form handling.
snippet.py
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from django.views.generic import ListView, CreateViewfrom django.urls import reverse_lazyfrom django.contrib.auth.mixins import LoginRequiredMixinfrom myapp.models import Bookclass BookFormMixin:def get_form_kwargs(self):kwargs = super().get_form_kwargs()kwargs['user'] = self.request.userreturn kwargsclass BookListView(LoginRequiredMixin, BookFormMixin, ListView):model = Bookcontext_object_name = 'books'paginate_by = 20def get_queryset(self):return Book.objects.filter(owner=self.request.user)class BookCreateView(LoginRequiredMixin, BookFormMixin, CreateView):model = Bookfields = ['title', 'author', 'isbn']success_url = reverse_lazy('book-list')def form_valid(self, form):form.instance.owner = self.request.userreturn super().form_valid(form)
django
Breakdown
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LoginRequiredMixin, BookFormMixin, ListView
Multiple inheritance order - Mixins are checked right-to-left for method resolution
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get_form_kwargs()
Override in mixin to inject extra data into form initialization
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form_valid()
Callback after successful form submission - sets owner before saving