Add i18n support in F2

[markhealey]

Opening an issue to track this request for i18n support in F2. The team has had some loose discussions on the topic of string and number formatting in containers and apps, and the upcoming Developer Center & Registry will have support for saving localization data.

In a hurry last week, I made a gist of possible i18n support for string replacement based on the language set by the Container Provider.

More to come...

[markhealey]

We have a formal proposed addition for i18n support. It is as follows. Comments & feedback welcome as we're hoping to add this support in version 1.4 (#142).

• Extend ContainerConfig and AppConfig objects to include new property called “locale” for definition of user’s language and region.
  • Property type will be String and valid values will the IETF-defined standard language tag. The IETF standard includes ISO 639 macrolanguage standard and ISO 3166-1 country code standard. For example, “en-us” and “de-de” are tags for “english united states” and “german germany”, respectively.
• The AppConfig’s “locale” property must be assumed as the default for the App. The default is null.
• TheAppConfig object will be extended to include an additional property called “localeSupport” so an App can make known all of its supported locales.
  • Property type will be Array and will contain IETF tags, e.g., “[‘en-us’,’de-de’]”.
• F2 will be updated to ensure the “locale” property gets passed from F2.init() to each App request.
• A new function will be added to F2 called “getLocale” on the F2 global. This will return the ContainerConfig-defined locale or null.
• Example reference implementation Container & App will be provided along with the other examples already in the F2 repository.

[markhealey]

Updating proposal:

• [x] Extend ContainerConfig to include new property called locale for definition of Container's language and region for use in F2.init.
  • Property type will be String and valid values will the IETF-defined standard language tag. The IETF standard includes ISO 639 macrolanguage standard and ISO 3166-1 country code standard. For example, “en-us” and “de-de” are tags for “english united states” and “german germany”, respectively.
  • Default will be null
• [x] TheAppConfig object will be extended to include a property called localeSupport so an App can make known all of its supported locales.
  • Property type will be Array and will contain IETF tags, e.g., [‘en-us’,’de-de’].
  • Default will be []
• [x] TheAppConfig object will be extended during F2.registerApps to include a containerLocale property so it is passed to each AppManifest request.
• [x] A new function will be added to F2 called getContainerLocale() on the F2 namespace. This will return the ContainerConfig-defined locale or null.
• [x] A new constant will be added to F2.Constants.Events called LOCALE_CHANGE
• [x] Example reference implementation Container & App will be provided along with the other examples already in the F2 repository.
• [x] Unit tests
• [x] Update docs (#193)

[markhealey]

Fixed #191 and #193