Opened 12 years ago
Closed 3 years ago
#20296 closed New feature (fixed)
django.utils.safestring.mark_safe forces evaluation of lazy objects
Reported by: | Baptiste Mispelon | Owned by: | Theofilos Alexiou |
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Component: | Utilities | Version: | dev |
Severity: | Normal | Keywords: | |
Cc: | bmispelon@… | Triage Stage: | Ready for checkin |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
Consider the following example:
from django.utils.safestring import mark_safe from django.utils.translation import activate, ugettext_lazy as _ s = mark_safe(_("username")) tpl = Template('{{ s }}') activate('fr') print(tpl.render(Context({'s': s})))
I would expect this to output nom d'utilisateur
(which is the french translation of username
) but what happens instead is that it outputs username
.
The reason for this is that mark_safe
will force the evaluation of the lazy string provided by ugettext_lazy
when it's called.
Unfortunately, the solution to this it trickier than simply wrapping mark_safe
with django.utils.functional.allow_lazy
, because mark_safe
can operate both on bytes and text (and allow_lazy
needs to know the type of object return by the wrapped function).
I wrote some tests and a proposed solution on my branch: https://github.com/bmispelon/django/compare/lazy-safedata
Change History (14)
comment:1 by , 11 years ago
Cc: | added |
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comment:2 by , 11 years ago
Triage Stage: | Unreviewed → Accepted |
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comment:3 by , 11 years ago
Triage Stage: | Accepted → Ready for checkin |
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I verified the problem exists.
The patch fixes the problem, and has tests.
comment:4 by , 11 years ago
Since it might not be clear, I'd like to point that the reason we can't simply decorate mark_safe
with allow_lazy
is that mark_safe
can return either bytes or text.
The allow_lazy
decorator cannot handle this case (there are specific checks in the code for it). [1]
[1] https://github.com/django/django/blob/master/django/utils/functional.py#L106
comment:5 by , 11 years ago
Resolution: | → fixed |
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Status: | new → closed |
comment:7 by , 11 years ago
Resolution: | fixed |
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Status: | closed → new |
Triage Stage: | Ready for checkin → Accepted |
A better fix for the issue is here: https://github.com/django/django/pull/2234
comment:9 by , 10 years ago
Has patch: | unset |
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Patch needs improvement: | unset |
I closed the PR (it is still there for anyone who'd like to see how it looked like).
If I have some time, I'll try to see if the approach still works and I'll reopen it.
Thanks for the ping.
comment:10 by , 8 years ago
In the steps to reproduce, should mark_safe()
be inside ugettext_lazy()
as in #27803 instead of the other way around? If so, maybe this is a wontfix, assuming the documentation is clear about proper usage.
comment:11 by , 3 years ago
Owner: | changed from | to
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Status: | new → assigned |
This should be an easy fix now I believe. mark_safe
no longer operates on both bytes and text, so wrapping it with keep_lazy
(the new allow_lazy
) should solve the issue.
comment:13 by , 3 years ago
Triage Stage: | Accepted → Ready for checkin |
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I created a pull request: https://github.com/django/django/pull/1093