Use HTTP headers for i18n

[hursey013]

This uses the http_accept_language gem to parse the Accept-Language header and match it up with our available translations.

[zachmargolis]

I think we want to drop this I18n.locale = line because it would mask the work that the Accept-Language header should be doing

[zachmargolis]

I would set an explicit , locale: 'en') inside the t( here

[zachmargolis]

we might want to make this configurable, or different in the different environments? (ex make it %w[en] for production but then make it %w[en es] for test and development?

The reason is that if somebody visits the IDP today with a Spanish browser, they'd see a bunch of "NOT TRANSLATED YET" strings

[zachmargolis]

Based on this build failure we probably need to add an after to these specs setting the locale back to English, or a default before for all specs:

  1) LOA3 Single Sign On canceling verification with js returns user to profile page if they have previously signed up
     Failure/Error: click_on t('links.cancel')
     
     Capybara::ElementNotFound:
       Unable to find link or button "Cancelar"
     # ./spec/features/saml/loa3_sso_spec.rb:135:in `block (4 levels) in <top (required)>'
  2) LOA3 Single Sign On canceling verification with js returns user to personal key page if they sign up via loa3
     Failure/Error: click_on t('links.cancel')
     
     Capybara::ElementNotFound:
       Unable to find link or button "Cancelar"
     # ./spec/features/saml/loa3_sso_spec.rb:124:in `block (4 levels) in <top (required)>'

[amoose]

Should be plural per:
config.i18n.available_locales = Figaro.env.available_locales.split(' ')

[zachmargolis]

I don't think this should be an allow, IMO we should just set the locale each time. As written, during a test run, something could set the locale to something other than :en but it would always be read back as :en which is wrong

I18n.locale = :en

[hursey013]

thanks @zachmargolis, still getting the hang of the semantics of rspec. updated PR w/ your feedback.

[zachmargolis]

LGTM!

Might want to wait to merge until there's devops support (or at least a default value for the lower envs) but the code here is fine to me

[amoose]

DevOps PR: https://github.com/18F/identity-devops/pull/375

[amoose]

This method needs to be updated in order to accept the user's selection (URL param) for locale.

[amoose]

Also, we need to add a method to sanitize the URL parameter. If the URL parameter does not match an available locale, it will throw an error.

[hursey013]

@amoose I am working on implementing the functionality with the params in a different branch, this was just focused on the HTTP headers, but I can roll it all into this one if that is preferred? https://github.com/18F/identity-idp/compare/bh-param-i18n

[amoose]

ah ok! no problem. Then, let's strip the params[:locale] from this PR and push without my commit in there.

[hursey013]

@amoose updated!

[amoose]

Looks like this needs to be rebased, Bhurst. I'm going to push the DevOps PR through today so I hope to merge this later. Please also squash the fixup commits 👍

[hursey013]

@amoose done!