determinePreferredLanguage() + registerAvailableLanguageKeys() still try to load unavailable language

[PaulAnnekov]

When using determinePreferredLanguage() function to automatically detect language based on Navigator and registerAvailableLanguageKeys() to set available languages list, if unavailable language detected, then angular translate still tries to load it using translation loader. Why does it do this? It's unavailable.
POC: plunker

[knalli]

Yeah, this sounds valid.

We have to revisit

angular-translate/src/service/translate.js

Lines 183 to 185 in c5c20ac

	if (parts.length > 1 && indexOf(avail, angular.lowercase(parts[0])) > -1) {
	return parts[0];
	}

[tspaeth]

Question - Implementation should be:

No matter, what determinePreferredLanguage analyzed - the registerAvailableLanguageKeys - output defines the valid languages.
Therefore if your browser is de-DE and this is the preferred due to this - which of the languages shall be chosen as the active one by the module?

Usually, you could now define this wildcard mapping as a second parameter (maybe needing the correct mappings in before - didn'T test it:

registerAvailableLanguageKeys(languages, {
      "*": "ar"
    })

[knalli]

Therefore if your browser is de-DE and this is the preferred due to this - which of the languages shall be chosen as the active one by the module?

The fallback one.

Perhaps we should log a warning if the combo preferredLanguage + available + fallback will result into nothing..

[knalli]

Fixed with bde935e -- with test case.