fix: shifting book from function based to class based view

books/urls.py

 from django.urls import path
-from .views import index, update, delete
+from books.views import BookListView, BookCreateView, BookUpdateView, BookDeleteView
 
 urlpatterns = [
-    path("", index, name="book_list"),
-    path("<int:id>/update/", update, name="book_update"),
-    path("<int:id>/delete/", delete, name="book_delete"),
+    path("", BookListView.as_view(), name="book_list"),
+    path("add/", BookCreateView.as_view(), name="book_update"),
+    path("<int:pk>/", BookUpdateView.as_view(), name="book_update"),
+    path("<int:pk>/delete/", BookDeleteView.as_view(), name="book_delete"),
 ]

books/views.py

-from django.shortcuts import get_object_or_404, render
-
-from django.http import HttpResponseRedirect
-from datetime import datetime
 from django.db.models import Q
-
+from django.views import generic
 from books.models import Book
 from books.forms import BookForm
-from django.core.paginator import Paginator, PageNotAnInteger, EmptyPage
-
-
-def index(request):
-    context = {"form": BookForm()}
-    books = Book.objects.all()
-
-    default_page = 1
-    page = request.GET.get("page", default_page)
-    items_per_page = 5
-    paginator = Paginator(books, items_per_page)
-
-    try:
-        page_obj = paginator.page(page)
-        context["page_obj"] = page_obj
-        context["books"] = page_obj
-
-    except PageNotAnInteger:
-        page_obj = paginator.page(default_page)
-        context["page_obj"] = page_obj
-        context["books"] = page_obj
-
-    except EmptyPage:
-        page_obj = paginator.page(paginator.num_pages)
-        context["page_obj"] = page_obj
-        context["books"] = page_obj
 
-    if request.method == "POST":
-        form = BookForm(request.POST)
-        if form.is_valid:
-            title = form.data["title"]
-            stock = form.data["stock"]
-            description = form.data["description"]
 
-            Book.objects.create(title=title, stock=stock, description=description)
+class BookListView(generic.ListView):
+    model = Book
+    template_name = "books.html"
+    paginate_by = 5
 
-    if request.method == "GET":
-        keyword = request.GET.get("q")
-        order = request.GET.get("o")
+    def get_queryset(self):
+        queryset = super().get_queryset()
+        keyword = self.request.GET.get("q")
+        order = self.request.GET.get("o")
 
-        if keyword is not None:
-
-            filtered_book_list = Book.objects.filter(
+        if keyword:
+            queryset = queryset.filter(
                 Q(title__icontains=keyword) | Q(description__icontains=keyword)
             ).order_by("-created_at")
-            context["books"] = filtered_book_list
-
-        if order == "new":
-
-            context["books"] = Book.objects.all().order_by("-updated_at")
-        elif order == "old":
-
-            context["books"] = Book.objects.all().order_by("updated_at")
-
-    return render(request, "book.html", context)
-
-
-def update(request, id):
-    latest_book_list = Book.objects.order_by("created_at")
-    context = {"books": latest_book_list}
-    book = Book.objects.get(id=id)
-    initial_dict = {
-        "title": book.title,
-        "stock": book.stock,
-        "description": book.description,
-    }
-    print(book.title)
-    form = BookForm(request.POST or None, initial=initial_dict)
-
-    if request.method == "POST":
-        if form.is_valid:
-            title = form.data["title"]
-            stock = form.data["stock"]
-            description = form.data["description"]
-            book = Book.objects.filter(id=id)
 
-            book.update(
-                title=title,
-                stock=stock,
-                description=description,
-                updated_at=datetime.now(),
-            )
+        if order:
+            if order == "new":
+                queryset = queryset.order_by("-created_at")
+            elif order == "old":
+                queryset = queryset.order_by("created_at")
 
-            return HttpResponseRedirect("/dashboard/books")
+        return queryset.order_by("-updated_at")
 
-    context["form"] = form
-    context["book_id"] = id
-    return render(request, "book_update_form.html", context)
 
+class BookCreateView(generic.edit.CreateView):
+    model = Book
+    form_class = BookForm
+    success_url = "/dashboard/books/"
+    template_name = "form/create_form.html"
 
-def delete(request, id):
-    context = {}
-    book = get_object_or_404(Book, id=id)
 
-    if request.method == "POST":
-        book.delete()
+class BookUpdateView(generic.edit.UpdateView):
+    model = Book
+    form_class = BookForm
+    success_url = "/dashboard/books"
+    template_name = "form/update_form.html"
 
-        return HttpResponseRedirect("/dashboard/books")
 
-    return render(request, "book.html", context)
+class BookDeleteView(generic.edit.DeleteView):
+    model = Book
+    success_url = "/dashboard/books"
+    template_name = "form/delete_form.html"