=====================
Generic editing views
=====================

The following views are described on this page and provide a foundation for
editing content:

* :class:`django.views.generic.edit.FormView`
* :class:`django.views.generic.edit.CreateView`
* :class:`django.views.generic.edit.UpdateView`
* :class:`django.views.generic.edit.DeleteView`

.. seealso::

    The :doc:`messages framework </ref/contrib/messages>` contains
    :class:`~django.contrib.messages.views.SuccessMessageMixin`, which
    facilitates presenting messages about successful form submissions.

.. note::

    Some of the examples on this page assume that an ``Author`` model has been
    defined as follows in ``myapp/models.py``::

        from django.db import models
        from django.urls import reverse

        class Author(models.Model):
            name = models.CharField(max_length=200)

            def get_absolute_url(self):
                return reverse('author-detail', kwargs={'pk': self.pk})

``FormView``
============

.. class:: django.views.generic.edit.FormView

    A view that displays a form. On error, redisplays the form with validation
    errors; on success, redirects to a new URL.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.base.TemplateResponseMixin`
    * :class:`django.views.generic.edit.BaseFormView`
    * :class:`django.views.generic.edit.FormMixin`
    * :class:`django.views.generic.edit.ProcessFormView`
    * :class:`django.views.generic.base.View`

    **Example myapp/forms.py**::

        from django import forms

        class ContactForm(forms.Form):
            name = forms.CharField()
            message = forms.CharField(widget=forms.Textarea)

            def send_email(self):
                # send email using the self.cleaned_data dictionary
                pass

    **Example myapp/views.py**::

        from myapp.forms import ContactForm
        from django.views.generic.edit import FormView

        class ContactFormView(FormView):
            template_name = 'contact.html'
            form_class = ContactForm
            success_url = '/thanks/'

            def form_valid(self, form):
                # This method is called when valid form data has been POSTed.
                # It should return an HttpResponse.
                form.send_email()
                return super().form_valid(form)

    **Example myapp/contact.html**:

    .. code-block:: html+django

        <form method="post">{% csrf_token %}
            {{ form.as_p }}
            <input type="submit" value="Send message">
        </form>

.. class:: django.views.generic.edit.BaseFormView

    A base view for displaying a form. It is not intended to be used directly,
    but rather as a parent class of the
    :class:`django.views.generic.edit.FormView` or other views displaying a
    form.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.edit.FormMixin`
    * :class:`django.views.generic.edit.ProcessFormView`

``CreateView``
==============

.. class:: django.views.generic.edit.CreateView

    A view that displays a form for creating an object, redisplaying the form
    with validation errors (if there are any) and saving the object.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.detail.SingleObjectTemplateResponseMixin`
    * :class:`django.views.generic.base.TemplateResponseMixin`
    * :class:`django.views.generic.edit.BaseCreateView`
    * :class:`django.views.generic.edit.ModelFormMixin`
    * :class:`django.views.generic.edit.FormMixin`
    * :class:`django.views.generic.detail.SingleObjectMixin`
    * :class:`django.views.generic.edit.ProcessFormView`
    * :class:`django.views.generic.base.View`

    **Attributes**

    .. attribute:: template_name_suffix

        The ``CreateView`` page displayed to a ``GET`` request uses a
        ``template_name_suffix`` of ``'_form'``. For
        example, changing this attribute to ``'_create_form'`` for a view
        creating objects for the example ``Author`` model would cause the
        default ``template_name`` to be ``'myapp/author_create_form.html'``.

    .. attribute:: object

        When using ``CreateView`` you have access to ``self.object``, which is
        the object being created. If the object hasn't been created yet, the
        value will be ``None``.

    **Example myapp/views.py**::

        from django.views.generic.edit import CreateView
        from myapp.models import Author

        class AuthorCreateView(CreateView):
            model = Author
            fields = ['name']

    **Example myapp/author_form.html**:

    .. code-block:: html+django

        <form method="post">{% csrf_token %}
            {{ form.as_p }}
            <input type="submit" value="Save">
        </form>

.. class:: django.views.generic.edit.BaseCreateView

    A base view for creating a new object instance. It is not intended to be
    used directly, but rather as a parent class of the
    :class:`django.views.generic.edit.CreateView`.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.edit.ModelFormMixin`
    * :class:`django.views.generic.edit.ProcessFormView`

    **Methods**

    .. method:: get(request, *args, **kwargs)

        Sets the current object instance (``self.object``) to ``None``.

    .. method:: post(request, *args, **kwargs)

        Sets the current object instance (``self.object``) to ``None``.

``UpdateView``
==============

.. class:: django.views.generic.edit.UpdateView

    A view that displays a form for editing an existing object, redisplaying
    the form with validation errors (if there are any) and saving changes to
    the object. This uses a form automatically generated from the object's
    model class (unless a form class is manually specified).

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.detail.SingleObjectTemplateResponseMixin`
    * :class:`django.views.generic.base.TemplateResponseMixin`
    * :class:`django.views.generic.edit.BaseUpdateView`
    * :class:`django.views.generic.edit.ModelFormMixin`
    * :class:`django.views.generic.edit.FormMixin`
    * :class:`django.views.generic.detail.SingleObjectMixin`
    * :class:`django.views.generic.edit.ProcessFormView`
    * :class:`django.views.generic.base.View`

    **Attributes**

    .. attribute:: template_name_suffix

        The ``UpdateView`` page displayed to a ``GET`` request uses a
        ``template_name_suffix`` of ``'_form'``. For
        example, changing this attribute to ``'_update_form'`` for a view
        updating objects for the example ``Author`` model would cause the
        default ``template_name`` to be ``'myapp/author_update_form.html'``.

    .. attribute:: object

        When using ``UpdateView`` you have access to ``self.object``, which is
        the object being updated.

    **Example myapp/views.py**::

        from django.views.generic.edit import UpdateView
        from myapp.models import Author

        class AuthorUpdateView(UpdateView):
            model = Author
            fields = ['name']
            template_name_suffix = '_update_form'

    **Example myapp/author_update_form.html**:

    .. code-block:: html+django

        <form method="post">{% csrf_token %}
            {{ form.as_p }}
            <input type="submit" value="Update">
        </form>

.. class:: django.views.generic.edit.BaseUpdateView

    A base view for updating an existing object instance. It is not intended to
    be used directly, but rather as a parent class of the
    :class:`django.views.generic.edit.UpdateView`.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.edit.ModelFormMixin`
    * :class:`django.views.generic.edit.ProcessFormView`

    **Methods**

    .. method:: get(request, *args, **kwargs)

        Sets the current object instance (``self.object``).

    .. method:: post(request, *args, **kwargs)

        Sets the current object instance (``self.object``).

``DeleteView``
==============

.. class:: django.views.generic.edit.DeleteView

    A view that displays a confirmation page and deletes an existing object.
    The given object will only be deleted if the request method is ``POST``. If
    this view is fetched via ``GET``, it will display a confirmation page that
    should contain a form that POSTs to the same URL.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.detail.SingleObjectTemplateResponseMixin`
    * :class:`django.views.generic.base.TemplateResponseMixin`
    * :class:`django.views.generic.edit.BaseDeleteView`
    * :class:`django.views.generic.edit.DeletionMixin`
    * :class:`django.views.generic.edit.FormMixin`
    * :class:`django.views.generic.base.ContextMixin`
    * :class:`django.views.generic.detail.BaseDetailView`
    * :class:`django.views.generic.detail.SingleObjectMixin`
    * :class:`django.views.generic.base.View`

    **Attributes**

    .. attribute:: form_class

        Inherited from :class:`~django.views.generic.edit.BaseDeleteView`. The
        form class that will be used to confirm the request. By default
        :class:`django.forms.Form`, resulting in an empty form that is always
        valid.

        By providing your own ``Form`` subclass, you can add additional
        requirements, such as a confirmation checkbox, for example.

    .. attribute:: template_name_suffix

        The ``DeleteView`` page displayed to a ``GET`` request uses a
        ``template_name_suffix`` of ``'_confirm_delete'``. For
        example, changing this attribute to ``'_check_delete'`` for a view
        deleting objects for the example ``Author`` model would cause the
        default ``template_name`` to be ``'myapp/author_check_delete.html'``.

    **Example myapp/views.py**::

        from django.urls import reverse_lazy
        from django.views.generic.edit import DeleteView
        from myapp.models import Author

        class AuthorDeleteView(DeleteView):
            model = Author
            success_url = reverse_lazy('author-list')

    **Example myapp/author_confirm_delete.html**:

    .. code-block:: html+django

        <form method="post">{% csrf_token %}
            <p>Are you sure you want to delete "{{ object }}"?</p>
            {{ form }}
            <input type="submit" value="Confirm">
        </form>

.. class:: django.views.generic.edit.BaseDeleteView

    A base view for deleting an object instance. It is not intended to be used
    directly, but rather as a parent class of the
    :class:`django.views.generic.edit.DeleteView`.

    **Ancestors (MRO)**

    This view inherits methods and attributes from the following views:

    * :class:`django.views.generic.edit.DeletionMixin`
    * :class:`django.views.generic.edit.FormMixin`
    * :class:`django.views.generic.detail.BaseDetailView`