==================
django-markupfield
==================
.. image:: https://github.com/jamesturk/django-markupfield/workflows/Test/badge.svg
.. image:: https://img.shields.io/pypi/v/django-markupfield.svg
:target: https://pypi.python.org/pypi/django-markupfield
An implementation of a custom MarkupField for Django. A MarkupField is in
essence a TextField with an associated markup type. The field also caches
its rendered value on the assumption that disk space is cheaper than CPU
cycles in a web application.
Installation
============
The recommended way to install django-markupfield is with
`pip <https://pypi.python.org/pypi/pip>`_
It is not necessary to add ``'markupfield'`` to your ``INSTALLED_APPS``, it
merely needs to be on your ``PYTHONPATH``. However, to use titled markup you
either add ``'markupfield'`` to your ``INSTALLED_APPS`` or add the
corresponding translations to your project translation.
Requirements
------------
Requires Django >= 2.2 and 3.6+
* 1.5.x is the last release to officially support Django < 2.2 or Python 2.7
* 1.4.x is the last release to officially support Django < 1.11
* 1.3.x is the last release to officially support Django 1.4 or Python 3.3
Settings
========
To best make use of MarkupField you should define the
``MARKUP_FIELD_TYPES`` setting, a mapping of strings to callables that
'render' a markup type::
import markdown
from docutils.core import publish_parts
def render_rest(markup):
parts = publish_parts(source=markup, writer_name="html4css1")
return parts["fragment"]
MARKUP_FIELD_TYPES = (
('markdown', markdown.markdown),
('ReST', render_rest),
)
If you do not define a ``MARKUP_FIELD_TYPES`` then one is provided with the
following markup types available:
html:
allows HTML, potentially unsafe
plain:
plain text markup, calls urlize and replaces text with linebreaks
markdown:
default `markdown`_ renderer (only if `markdown`_ is installed)
restructuredtext:
default `ReST`_ renderer (only if `docutils`_ is installed)
It is also possible to override ``MARKUP_FIELD_TYPES`` on a per-field basis
by passing the ``markup_choices`` option to a ``MarkupField`` in your model
declaration.
.. _`ReST`: http://docutils.sourceforge.net/rst.html
.. _`markdown`: https://pypi.python.org/pypi/Markdown
.. _`docutils`: http://docutils.sourceforge.net/
Usage
=====
Using MarkupField is relatively easy, it can be used in any model definition::
from django.db import models
from markupfield.fields import MarkupField
class Article(models.Model):
title = models.CharField(max_length=100)
slug = models.SlugField(max_length=100)
body = MarkupField()
``Article`` objects can then be created with any markup type defined in
``MARKUP_FIELD_TYPES``::
Article.objects.create(title='some article', slug='some-article',
body='*fancy*', body_markup_type='markdown')
You will notice that a field named ``body_markup_type`` exists that you did
not declare, MarkupField actually creates two extra fields here
``body_markup_type`` and ``_body_rendered``. These fields are always named
according to the name of the declared ``MarkupField``.
Arguments
---------
``MarkupField`` also takes three optional arguments. Either
``default_markup_type`` and ``markup_type`` arguments may be specified but
not both.
``default_markup_type``:
Set a markup_type that the field will default to if one is not specified.
It is still possible to edit the markup type attribute and it will appear
by default in ModelForms.
``markup_type``:
Set markup type that the field will always use, ``editable=False`` is set
on the hidden field so it is not shown in ModelForms.
``markup_choices``:
A replacement list of markup choices to be used in lieu of
``MARKUP_FIELD_TYPES`` on a per-field basis.
``escape_html``:
A flag (False by default) indicating that the input should be regarded
as untrusted and as such will be run through Django's ``escape`` filter.
Examples
~~~~~~~~
``MarkupField`` that will default to using markdown but allow the user a choice::
MarkupField(default_markup_type='markdown')
``MarkupField`` that will use ReST and not provide a choice on forms::
MarkupField(markup_type='restructuredtext')
``MarkupField`` that will use a custom set of renderers::
CUSTOM_RENDERERS = (
('markdown', markdown.markdown),
('wiki', my_wiki_render_func)
)
MarkupField(markup_choices=CUSTOM_RENDERERS)
.. note::
When using ``markdown``, be sure to use ``markdown.markdown`` and not
the ``markdown.Markdown`` class, the class requires an explicit ``reset``
to function properly in some cases. (See [issue #40](https://github.com/jamesturk/django-markupfield/issues/40)
for details.)
Accessing a MarkupField on a model
----------------------------------
When accessing an attribute of a model that was declared as a ``MarkupField``
a special ``Markup`` object is returned. The ``Markup`` object has three
parameters:
``raw``:
The unrendered markup.
``markup_type``:
The markup type.
``rendered``:
The rendered HTML version of ``raw``, this attribute is read-only.
This object has a ``__unicode__`` method that calls
``django.utils.safestring.mark_safe`` on ``rendered`` allowing MarkupField
objects to appear in templates as their rendered selfs without any template
tag or having to access ``rendered`` directly.
Assuming the ``Article`` model above::
>>> a = Article.objects.all()[0]
>>> a.body.raw
u'*fancy*'
>>> a.body.markup_type
u'markdown'
>>> a.body.rendered
u'<p><em>fancy</em></p>'
>>> print unicode(a.body)
<p><em>fancy</em></p>
Assignment to ``a.body`` is equivalent to assignment to ``a.body.raw`` and
assignment to ``a.body_markup_type`` is equivalent to assignment to
``a.body.markup_type``.
.. important::
Keeping in mind that ``body`` is MarkupField instance is particullary important with ``default`` or ``default_if_none`` filter for model that could be blank. If ``body``'s ``rendered`` is ``None`` or empty string (``""``) these filters will *not* evaluate ``body`` as falsy to display default text::
{{ a.body|default:"<missing body>" }}
That's because ``body`` is regular non-``None`` MarkupField instance. To let ``default`` or ``default_if_none`` filters to work evaluate ``rendered`` MarkupField attribute instead. To prevent escaping HTML for the case ``rendered`` is truethy, finish chain with ``safe`` filter::
{{ a.body.rendered|default:"<missing body>"|safe }}
.. note::
a.body.rendered is only updated when a.save() is called