Embedding HTML in Django Messages
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You want to embed HTML within a message using Django's messages framework.
This is a reasonably common requirement - for instance, it's common to want to include a link within the message, perhaps pointing the user towards a sign-in or registration page.
This problem exists as of Django 1.4 but may be solved within the framework in later versions.
Solution
Use the extra_tags keyword argument to pass a flag indicating that the message is safe for rendering without escaping. For example:
from django.contrib import messages def some_view(request): ... messages.success(request, 'Here is a <a href="/">link</a>.', extra_tags='safe')
Then use some simple template logic to determine whether to use the safe filter:
<ul> {% for message in messages %} <li class="{{ message.tags }}"> {% if 'safe' in message.tags %} {{ message|safe }} {% else %} {{ message }} {% endif %} </li> {% endfor %} </ul>
Discussion
It's tempting to use the safe filter for all messages but this opens up a XSS security hole if you are not careful as it's easy to include user input verbatim in the message. For instance:
from django.contrib import messages def some_view(request): code = request.GET['code'] ... messages.success(request, "'%s' is not valid voucher code" % code)
leads to an XSS hole if the safe filter is used on all messages as the contents of request.GET['code'] cannot be trusted. It's better to explicitly indicate which messages can be safely rendered without escaping.
Published at DZone with permission of David Winterbottom, DZone MVB. See the original article here.
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