Opened 9 years ago

Last modified 9 years ago

#339 closed enhancement (FIXED)

Let jinja throw errors on undefined variables

Reported by: Elrond Owned by: Elrond
Priority: trivial Milestone: 0.2.1
Component: programming Keywords:
Cc: Parent Tickets:


(this is to discuss this and then possibly implement it.
Implementing is **very** easy).

Currently jinja2 replaces ``{{ not_known }}`` by the empty string.
The question is, wether it would be better for it to throw an
error? Rationale being: Either it's a typo, or it's an error for
the variable to be referenced but not being there.

Does that make sense?

Enabling this:


    @@ -43,6 +43,7 @@ def get_jinja_env(template_loader, locale):
         template_env = jinja2.Environment(
             loader=template_loader, autoescape=True,
    +        undefined=jinja2.StrictUndefined,
             extensions=['jinja2.ext.i18n', 'jinja2.ext.autoescape'])


Change History (7)

comment:1 Changed 9 years ago by Elrond

Component: Programming
Priority: NormalLow

comment:1 Changed 9 years ago by Christopher Allan Webber

Hm. There might be some places where this would be nicer.

I remember when working with ZPT that it would complain on these
things, it was nice in some places {{ foo }} but less in other
places {{ objyoudohave.fooyoudont }}... being able to call
attributes that you don't actually have and it going silent is
nice. That said I remember a few years ago saying that ZPT
complaining about such things was a significant feature in
comparison to Django's templates.

How's that for a non-answer ;)

comment:2 Changed 9 years ago by Elrond

jinja2 has a ``defined`` test. That should help if you have an
attribute that purposefully might or might not exist.

Edit: We might also conider
`jinja2.DebugUndefined <>`_

comment:3 Changed 9 years ago by Elrond

Milestone: 0.2.1
Owner: set to Elvenlord Elrond
Status: NewIn Progress
Okay, I have enabled this. And fixed two breaking places (simple).

I leave this bug open for the next 14 days, if this all turns out
to be a bad idea.
Let's see!

Commit: f1cdd278e7cf195e485567ed0d0d8a90cad81e48 and following

comment:4 Changed 9 years ago by Elrond

Status: In ProgressClosed
13 days over, okay.
We had a small bit of pain here and there, but it generally was

comment:5 Changed 9 years ago by Will Kahn-Greene

The original url for this bug was .

comment:6 Changed 9 years ago by Elrond

Type: defectenhancement
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