1305 sections across all versions Narrow to Django 6.0 (current) →
Topic guide Using mixins with class-based views Avoid anything more complex
The number of subtle interactions between FormMixin and DetailView is already testing our ability to manage things. It’s unlikely you’d want to write this kind of class yourself.
Topic guide Using mixins with class-based views Avoid anything more complex
So why not do just that? We have a very clear division here: GET requests should get the DetailView (with the Form added to the context data), and POST requests should get the FormView. Let’s set up those views first.
Topic guide Multiple databases
Django’s admin doesn’t have any explicit support for multiple databases.
Topic guide Making queries Retrieving objects
Field lookups are how you specify the meat of an SQL WHERE clause. They’re specified as keyword arguments to the QuerySet methods filter(), exclude() and get(). Basic lookups keyword arguments take the form field__lookuptype=value. (That’s a double-underscore).
Topic guide Making queries Retrieving objects
… equivalent: The use of pk isn’t limited to __exact queries – any query term can be combined with pk to perform a query on the primary key of a model: pk lookups also work across joins. For example, these three …
Topic guide Making queries Querying JSONField
… based on a given dictionary key, use that key as the lookup name: Multiple keys can be chained together to form a path lookup: If the key is an integer, it will be interpreted as an index transform in an …
Topic guide Formsets
Initial data is what drives the main usability of a formset. As shown above you can define the number of extra forms.
Topic guide Formsets
The absolute_max parameter to formset_factory() allows limiting the number of forms that can be instantiated when supplying POST data. This protects against memory exhaustion attacks using forged POST requests: When absolute_max is None, it defaults to max_num + 1000.
Topic guide Formsets Dealing with ordering and deletion of forms
BaseFormSet.can_order Default: False Lets you create a formset with the ability to order: This adds an additional field to each form. This new field is named ORDER and is an forms.IntegerField.
Topic guide Formsets Dealing with ordering and deletion of forms
BaseFormSet.can_delete Default: False Lets you create a formset with the ability to select forms for deletion: Similar to can_order this adds a new field to each form named DELETE and is a forms.BooleanField.
Topic guide Formsets
If you need to add additional fields to the formset this can be easily accomplished. The formset base class provides an add_fields method.
Topic guide Working with forms Forms in Django
… the database, for example) pass it to the template context expand it to HTML markup using template variables Rendering a form in a template involves nearly the same work as rendering any other kind of object, but there are some …
Topic guide Creating forms from models ModelForm
Consider this set of models: With these models, the ModelForm subclasses above would be roughly equivalent to this (the only difference being the save() method, which we’ll discuss in a moment.):
Topic guide Creating forms from models ModelForm
You can create forms from a given model using the standalone function modelform_factory(), instead of using a class definition.
Topic guide Creating forms from models
classmodels.BaseModelFormSet Like regular formsets, Django provides a couple of enhanced formset classes to make working with Django models more convenient. Let’s reuse the Author model from above: Using fields restricts the formset to use only the given fields.
Topic guide Creating forms from models Model formsets
As with a ModelForm, you can save the data as a model object. This is done with the formset’s save() method: The save() method returns the instances that have been saved to the database.
Topic guide Creating forms from models Model formsets
There are three ways to render a formset in a Django template.
Topic guide File Uploads Basic file uploads
If you’re saving a file on a Model with a FileField, using a ModelForm makes this process much easier.
Topic guide How to use sessions
As a convenience, Django provides a way to test whether the user’s browser accepts cookies. Call the set_test_cookie() method of request.session in a view, and call test_cookie_worked() in a subsequent view – not in the same view call.
Topic guide Format localization
When formatting is enabled, Django can use localized formats when parsing dates, times and numbers in forms. That means it tries different formats for different locales when guessing the format used by the user when inputting data on forms.