I submitted the below to Django Users and Malcolm Tredinnick suggested I open a ticket. Essentially, when making custom widgets, I encountered a problem wherein despite marking things as safe strings, when I tried to render my forms in a template, they were beings escaped. Turning off auto escaping and piping to the safe filter weren't working, and I found that they were being escaped at a very low level. Namely, there is a call in the Widget.render function to django.forms.util.flatatt that is escaping everything. I don't know if this by design or not, but given the number of calls to mark_safe in the Widget module, I suspect not. It is preventing me from, for example, making JS function calls in widgets that require string arguments. I hope this helps.
Regards,
Alex.
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Hi there,
I have been trying to get a function call into a widget argument, but
have not been able to at the template level, because it would appear
that my safe_strings are being escaped somewhere down in the
framework. I have created a widget and mark_safe'd an attribute
value, but no matter what, since it's pre-escaped by the time it
bubbles up to the template level, I can't not escape it (well... I
could use an html library to de-escape it, but that seems kludgy).
I've traced the execution and found the culprit to be the
django.forms.util.flatatt function. That is:
from django import forms
from django.utils.safestring import mark_safe
class MyWidget(forms.TextInput):
def __init__(self, *args, **kwargs):
attrs = kwargs.setdefault('attrs', {})
attrs['safe_string'] = mark_safe("will o' the wisp")
attrs['normal_string'] = "cat o' nine tails"
super(MyWidget, self).__init__(*args, **kwargs)
w = MyWidget()
w.render("field_name", "")
#=> u'<input normal_string="cat o' nine tails" type="text"
name="field_name" safe_string="will o' the wisp" />'
You can see that both the unsafe and safe strings were escaped. I
don't know if this is intentional or not, but it prevents me from
making something like:
<input type="text" onBlur="myFunction('string_arg')">
because it is always escaping my single-quotes. Is this the desired
behavior? Anyway, like I said, the culprit is:
# django.forms.util
def flatatt(attrs):
"""
Convert a dictionary of attributes to a single
string.
The returned string will contain a leading space followed by
key="value",
XML-style pairs. It is assumed that the keys do not need to be
XML-
escaped.
If the passed dictionary is empty, then return an empty
string.
"""
return u''.join([u' %s="%s"' % (k, escape(v)) for k, v in
attrs.items()]) # <-- right there, the escape(v) call... should this
be conditional_escape?
Since there are a lot of calls to mark_safe scattered through the
widget and form-level calls used in rendering, I assume you're meant
to be able to mark something as safe down here and have it get to the
top level unaltered... no?
