[Zope3-dev] Use case not covered for translation of message ids

[Jim Fulton]

Godefroid Chapelle wrote:
> Hi,
> 
> while working at the mountain sprint on the port of message ids to Z2, 
> we found out that the following use case is not covered :
> 
> <div tal:content="string:My content item is of type ${type_msgid}." />
> 
> where type_msgid is a MessageID that a developer did define in Python 
> code for instance.
 >
> Currently, the message id is not translated : the id itself is 
> concatenated to the text in the string expression.

Good. This is correct behavior.

> This use case can be seen as wrong : the text "My content item is of 
> type" won't be translated.

I don't know what the use case is.  The behavior is correct.

> Ideally the template developer should have written :
> 
> <div i18n:translate="">My content item is of type <span 
> tal:replace="type_msgid" i18n:name="type" />.</div>

Yup

> Anyway, in the first case, the developer made his part of the job 
> correctly : he said that this value should be translated. So we think 
> that even if the template is badly written, the message id should be 
> translated.

I don't agree. Message IDs are just strings. They must be treated
as strings unless explicitly treated otherwise. The fact, as you
reported in a later message, that ZPT sometimes erroniously translates
implicitly is not a reason to do so now.

It makes no sense, in the above example, to try to guess that the
author intended to insert a translated string into the middle
of an untranslated English sentance.

The only sane alternave that I can see is to *not* treat message ids
as strings so that they can't cause accidental translation by being
incidentally used as strings.  I think that this would be too great
a change without much more debate.

> Please find hereunder a fix to class StringExpr from 
> zope/tales/expressions.py that solves this situation by allowing the 
> user to see the translation so that he can go and beat the template 
> designer ;-)
> 
> from zope.i18n.messageid import MessageID
> 
> 
>     def __call__(self, econtext):
>         vvals = []
>         for var in self._vars:
>             v = var(econtext)
>             if isinstance(v, MessageID):
>                 v = econtext.translate(v, domain=v.domain
>                        mapping=v.mapping, default=v.default)
>             vvals.append(v)
>         return self._expr % tuple(vvals)

Sorry, I have to reject this.

Jim

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