mirror of
https://github.com/django/django.git
synced 2025-10-29 00:26:07 +00:00
131 lines
4.8 KiB
Plaintext
131 lines
4.8 KiB
Plaintext
======================
|
|
The form rendering API
|
|
======================
|
|
|
|
.. module:: django.forms.renderers
|
|
:synopsis: Built-in form renderers.
|
|
|
|
Django's form widgets are rendered using Django's :doc:`template engines
|
|
system </topics/templates>`.
|
|
|
|
The form rendering process can be customized at several levels:
|
|
|
|
* Widgets can specify custom template names.
|
|
* Forms and widgets can specify custom renderer classes.
|
|
* A widget's template can be overridden by a project. (Reusable applications
|
|
typically shouldn't override built-in templates because they might conflict
|
|
with a project's custom templates.)
|
|
|
|
.. _low-level-widget-render-api:
|
|
|
|
The low-level render API
|
|
========================
|
|
|
|
The rendering of form templates is controlled by a customizable renderer class.
|
|
A custom renderer can be specified by updating the :setting:`FORM_RENDERER`
|
|
setting. It defaults to
|
|
``'``:class:`django.forms.renderers.DjangoTemplates`\ ``'``.
|
|
|
|
You can also provide a custom renderer by setting the
|
|
:attr:`.Form.default_renderer` attribute or by using the ``renderer`` argument
|
|
of :meth:`.Widget.render`.
|
|
|
|
Use one of the :ref:`built-in template form renderers
|
|
<built-in-template-form-renderers>` or implement your own. Custom renderers
|
|
must implement a ``render(template_name, context, request=None)`` method. It
|
|
should return a rendered templates (as a string) or raise
|
|
:exc:`~django.template.TemplateDoesNotExist`.
|
|
|
|
.. _built-in-template-form-renderers:
|
|
|
|
Built-in-template form renderers
|
|
================================
|
|
|
|
``DjangoTemplates``
|
|
-------------------
|
|
|
|
.. class:: DjangoTemplates
|
|
|
|
This renderer uses a standalone
|
|
:class:`~django.template.backends.django.DjangoTemplates`
|
|
engine (unconnected to what you might have configured in the
|
|
:setting:`TEMPLATES` setting). It loads templates first from the built-in form
|
|
templates directory in ``django/forms/templates`` and then from the installed
|
|
apps' templates directories using the :class:`app_directories
|
|
<django.template.loaders.app_directories.Loader>` loader.
|
|
|
|
If you want to render templates with customizations from your
|
|
:setting:`TEMPLATES` setting, such as context processors for example, use the
|
|
:class:`TemplatesSetting` renderer.
|
|
|
|
``Jinja2``
|
|
----------
|
|
|
|
.. class:: Jinja2
|
|
|
|
This renderer is the same as the :class:`DjangoTemplates` renderer except that
|
|
it uses a :class:`~django.template.backends.jinja2.Jinja2` backend. Templates
|
|
for the built-in widgets are located in ``django/forms/jinja2`` and installed
|
|
apps can provide templates in a ``jinja2`` directory.
|
|
|
|
To use this backend, all the widgets in your project and its third-party apps
|
|
must have Jinja2 templates. Unless you provide your own Jinja2 templates for
|
|
widgets that don't have any, you can't use this renderer. For example,
|
|
:mod:`django.contrib.admin` doesn't include Jinja2 templates for its widgets
|
|
due to their usage of Django template tags.
|
|
|
|
``TemplatesSetting``
|
|
--------------------
|
|
|
|
.. class:: TemplatesSetting
|
|
|
|
This renderer gives you complete control of how widget templates are sourced.
|
|
It uses :func:`~django.template.loader.get_template` to find widget
|
|
templates based on what's configured in the :setting:`TEMPLATES` setting.
|
|
|
|
Using this renderer along with the built-in widget templates requires either:
|
|
|
|
* ``'django.forms'`` in :setting:`INSTALLED_APPS` and at least one engine
|
|
with :setting:`APP_DIRS=True <TEMPLATES-APP_DIRS>`.
|
|
|
|
* Adding the built-in widgets templates directory in :setting:`DIRS
|
|
<TEMPLATES-DIRS>` of one of your template engines. To generate that path::
|
|
|
|
import django
|
|
django.__path__[0] + '/forms/templates' # or '/forms/jinja2'
|
|
|
|
Using this renderer requires you to make sure the form templates your project
|
|
needs can be located.
|
|
|
|
Context available in widget templates
|
|
=====================================
|
|
|
|
Widget templates receive a context from :meth:`.Widget.get_context`. By
|
|
default, widgets receive a single value in the context, ``widget``. This is a
|
|
dictionary that contains values like:
|
|
|
|
* ``name``
|
|
* ``value``
|
|
* ``attrs``
|
|
* ``is_hidden``
|
|
* ``template_name``
|
|
|
|
Some widgets add further information to the context. For instance, all widgets
|
|
that subclass ``Input`` defines ``widget['type']`` and :class:`.MultiWidget`
|
|
defines ``widget['subwidgets']`` for looping purposes.
|
|
|
|
.. _overriding-built-in-widget-templates:
|
|
|
|
Overriding built-in widget templates
|
|
====================================
|
|
|
|
Each widget has a ``template_name`` attribute with a value such as
|
|
``input.html``. Built-in widget templates are stored in the
|
|
``django/forms/widgets`` path. You can provide a custom template for
|
|
``input.html`` by defining ``django/forms/widgets/input.html``, for example.
|
|
See :ref:`built-in widgets` for the name of each widget's template.
|
|
|
|
To override widget templates, you must use the :class:`TemplatesSetting`
|
|
renderer. Then overriding widget templates works :doc:`the same as
|
|
</howto/overriding-templates>` overriding any other template in your project.
|