=====================
Django HTML Sanitizer
=====================
Django HTML Sanitizer provides a set of utilities to easily sanitize/escape/clean
HTML inputs in django. This app is built on top of `bleach <http://github.com/jsocol/bleach>`_,
the excellent Python HTML sanitizer.
Dependencies
============
- `django <http://djangoproject.com/>`_: http://djangoproject.com/
- `bleach <http://github.com/jsocol/bleach>`_: http://github.com/jsocol/bleach
Installation
============
You'll first need to install the package (or download manually from
`pypi <http://pypi.python.org/pypi/django-html_sanitizer>`_)::
pip install django-html_sanitizer
And then add ``sanitizer`` to your INSTALLED_APPS in django's ``settings.py``::
INSTALLED_APPS = (
# other apps
"sanitizer",
)
Model Usage
===========
Similar to bleach, django sanitizer is a whitelist (only allows specified tags
and attributes) based HTML sanitizer. Django sanitizer provides two model fields
that automatically sanitizes text values; ``SanitizedCharField`` and
``SanitizedTextField``.
These fields accept extra arguments:
* allowed_tags: a list of allowed HTML tags
* allowed_attributes: a list of allowed HTML attributes, or a dictionary of
tag keys with atttribute list for each key
* allowed_styles: a list of allowed styles if "style" is one of the allowed
attributes
* strip: a boolean indicating whether offending tags/attributes should be escaped or stripped
Here's how to use it in django models::
from django.db import models
from sanitizer.models import SanitizedCharField, SanitizedTextField
class MyModel(models.Model):
# Allow only <a>, <p>, <img> tags and "href" and "src" attributes
foo = SanitizedCharField(max_length=255, allowed_tags=['a', 'p', 'img'],
allowed_attributes=['href', 'src'], strip=False)
bar = SanitizedTextField(max_length=255, allowed_tags=['a', 'p', 'img'],
allowed_attributes=['href', 'src'], strip=False)
foo2 = SanitizedCharField(max_length=255, allowed_tags=['a', 'p', 'img'],
allowed_attributes={'img':['src', 'style']},
allowed_styles=['width', 'height'], strip=False)
Form Usage
==========
Using django HTML sanitizer in django forms is very similar to model usage::
from django import forms
from sanitizer.forms import SanitizedCharField
class MyForm(forms.Form):
# Allow only <a>, <p>, <img> tags and "href" and "src" attributes
foo = SanitizedCharField(max_length=255, allowed_tags=['a', 'p', 'img'],
allowed_attributes=['href', 'src'], strip=False)
bar = SanitizedCharField(max_length=255, allowed_tags=['a', 'p', 'img'],
allowed_attributes=['href', 'src'], strip=False, widget=forms.Textarea)
foo2 = SanitizedCharField(max_length=255, allowed_tags=['a', 'p', 'img'],
allowed_attributes={'img':['src', 'style']},
allowed_styles=['width', 'height'], strip=False)
Template Usage
==============
Django sanitizer provides a few differents ways of cleaning HTML in templates.
``escape_html`` Template Tag
----------------------------
Example usage::
{% load sanitizer %}
{% escape_html post.content "a, p, img" "href, src, style" "width"%}
Assuming ``post.content`` contains the string
'<a href ="#" style="width:200px; height="400px">Example</a><script>alert("x")</script>', the above tag will
output::
'<a href ="#" style="width:200px;">Example</a><script>alert("x")</script>'
On django 1.4 you could also use keyword arguments::
{% escape_html '<a href="">bar</a>' allowed_tags="a,img" allowed_attributes="href,src" allowed_styles="width" %}
``strip_html`` Template Tag
---------------------------
Example usage::
{% load sanitizer %}
{% strip_html post.content "a, p, img" "href, src" %}
If ``post.content`` contains the string
'<a href ="#">Example</a><script>alert("x")</script>', this will give you::
'<a href ="#">Example</a>alert("x")'
``escape_html`` Filter
----------------------
Escapes HTML tags from string based on settings. To use this filter you need to
put these variables on settings.py:
* ``SANITIZER_ALLOWED_TAGS`` - a list of allowed tags (defaults to an empty list)
* ``SANITIZER_ALLOWED_ATTRIBUTES`` - a list of allowed attributes (defaults to an empty list)
* ``SANITIZER_ALLOWED_STYLES`` - a list of allowed styles if the style attribute is set (defaults to an empty list)
For example if we have ``SANITIZER_ALLOWED_TAGS = ['a']``,
``SANITIZER_ALLOWED_ATTRIBUTES = ['href']``,
``SANITIZER_ALLOWED_STYLES = ['width']`` in settings.py, doing::
{% load sanitizer %}
{{ post.content|escape_html }}
If ``post.content`` contains the string
'<a href ="#" style="width:200px; height:400px">Example</a><script>alert("x")</script>', it will give you::
'<a href ="#" style="width=200px;">Example</a><script>alert("x")</script>'
``strip_html`` Filter
---------------------
Similar to ``escape_html`` filter, except it strips out offending HTML tags.
For example if we have ``SANITIZER_ALLOWED_TAGS = ['a']``,
``SANITIZER_ALLOWED_ATTRIBUTES = ['href']`` in settings.py, doing::
{% load sanitizer %}
{{ post.content|strip_html }}
If ``post.content`` contains the string
'<a href ="#">Example</a><script>alert("x")</script>', we will get::
'<a href ="#">Example</a>alert("x")'
Changelog
=========
Version 0.1.5
-------------
* Fixes for smart_unicode and basestring (python 3.x support)
Version 0.1.4
-------------
* ``CharField``, ``TextField``, ``strip_html`` and ``escape_html`` now support
``allowed_styles`` (thanks `cltrudeau <https://github.com/cltrudeau)>`_,
* Added an example of template tag usage using kwargs now that Django 1.4 is out
Version 0.1.2
-------------
* ``allowed_tags`` and ``allowed_attributes`` in CharField and TextField now default to []