Use generic views to display data

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The generic views system in Django streamlines the creation of repetitive code. The common operations you perform in a data-driven application share the same pattern. For example, to display an individual item by its ID or primary key, the workflow is always:

1. Load the item from the database by ID.
2. If the item isn't found, return a 404.
3. If the item is found, pass the item to a template for display.

The generic view system acknowledges this fact and provides classes you can use that contain the core code already written. You inherit from the appropriate class, set a couple of properties, and then register an appropriate path in your URLconf. The rest is taken care of for you!

Django includes two generic views for displaying data: DetailView and ListView.

DetailView for item detail

The generic view DetailView is used to display a detail page for an item. DetailView retrieves the item for the specified model by the primary key and passes it to the template. You can set template_name to the name of the template to be used. The default is <model>_detail.html. Finally, we can set context_object_name to the name of the variable we want to use in our template.

To create a detail view by using the generic view for a dog, you could use the following code:

from . import models
from django.views import generic

class DogDetailView(generic.DetailView):
    model = models.Dog
    template_name = 'dog_detail.html'
    context_object_name = 'dog'

Registering DogDetailView is similar to any other path entry. The key thing to ensure you include is a parameter named pk. Django uses this convention to identify the primary key. You'll also note we use the as_view() method to convert the class into a view.

path('dog/<int:pk>', views.DogDetailView.as_view(), name='dog_detail')

ListView for a list of items

The generic view ListView behaves in a similar fashion to DetailView. You can set context_object_name for the name of the variable in the view and template_name for the name of the template.

The primary difference is that ListView is designed to work with any form of a query that returns multiple items. As a result, you must override the get_queryset function. The functionget_queryset is called by the generic view system to retrieve the items from the database, which allows you to order or filter your items as needed.

To create a view to display the list of all shelters by using the generic view ListView, you could use the following code:

from . import models
from django.views import generic

class ShelterListView(generic.ListView):
    template_name = 'shelter_list.html'
    context_object_name = 'shelters'

    def get_queryset(self):
        return models.Shelter.objects.all()

Registering the view is performed much in the same way as our DetailView.

path('', ShelterListView.as_view(), name='shelter_list')