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, the excellent Python HTML sanitizer.

Dependencies

Installation

You'll first need to install the package:

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 three extra arguments: - allowed_tags: a list of allowed HTML tags - allowed_attributes: a list of allowed HTML 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)

Form Usage

Using django HTML sanitizer in django forms is very similar to model usage:

from django import forms
from sanitizer.forms import SanitizedCharField, SanitizedTextField

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 = SanitizedTextField(max_length=255, allowed_tags=['a', 'p', 'img'],
                             allowed_attributes=['href', 'src'], 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" %}

Assuming post.content contains the string '<a href ="#">Example</a><script>alert("x")</script>', the above tag will output:

'<a href ="#">Example</a>&lt;script&gt;alert("x")&lt;/script&gt;'

`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)

For example if we have SANITIZER_ALLOWED_TAGS = ['a'], SANITIZER_ALLOWED_ATTRIBUTES = ['href'] in settings.py, doing:

{% load sanitizer %}
{{ post.content|escape_html }}

If post.content contains the string '<a href ="#">Example</a><script>alert("x")</script>', it will give you:

'<a href ="#">Example</a>&lt;script&gt;alert("x")&lt;/script&gt;'

`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 0.1.2: allowed_tags and allowed_attributes in CharField and TextField now default to []

sebastien-worms/django-html_sanitizer