Weird i18n issues

[thomasdarde]

I've been searching for a solution.
Sometimes the flash messages is displayed in another locale then I18n.locale.

Any suggestion ?

[josevalim]

You need to give us more information on how to reproduce this issue, otherwise there is nothing we can do. Please read CONTRIBUTING.md file for more information about creating bug reports. Thanks!

[thomasdarde]

Hi José,
Thank you for your reply.

I think I finally found the problem. I had this bug a long time ago and never got time to really debug it. Solution is very dumb. Maybe you can confirm me what I suspect the problem is:

Devise controllers don't inheritate from AppplicationController. So a before_filter in ApplicationController setting I18n.locale is of no use.
Locale used by devise is then random or linked to I18n.locale used in the last request the server received ?

[thomasdarde]

I will make a PR on the doc side if it's confirmed, I believe I'm not the first one which had the problem

[josevalim]

Devise does inherit from ApplicationController. What may happen though is that you need to set the I18n locale using prepend_before_filter because some of Devise actions may set the filter earlier on to guarantee nothing runs while the user was not yet authenticated.

[thomasdarde]

Thanks a lot for all this information, I was able to undestrand and fix my app.
Also I've added #3060 in case I wasn't the only one with this problem.

[gingerlime]

we're having some strange issues, where when a user switches the locale and tries to login and fails, the flash alert message appears to be translated using the previous locale somehow. On second attempt, it looks ok, but any time we switch locales, the first alert will be shown with the previous locale...

We do have a before_filter on our application controller, and I even tried to change it to prepend_before_filter, but it doesn't seem to make a difference.

I do notice however that the flash message is added even before the new action is being called on our sessions controller... but also that the before filter is being called before the flash message is set (On my debugger I traced 1 call to this locale filter method before the flash is set, then another one where the flash is already set, and then the new action on sessions is being called...)

Any tips on how to resolve this?

[gingerlime]

Looks like changing the middleware position for dealing with locales can resolve this. See #4823 (comment)