Core: translation loader is not updating translations on change

[rolandjitsu]

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[x] support request => check the FAQ and search github for a similar issue before submitting
[ ] feature request

Current behavior
I'm using a custom loader, similar to FIREBASE_EXAMPLE.md, to get translations from Firebase. But it seems like if I change the db (from the FB dashboard), the changes are not reflected in the views.

Expected/desired behavior
The changes should be reflected when the translations observable emits.

Reproduction of the problem
If the current behavior is a bug or you can illustrate your feature request better with an example, please provide the steps to reproduce and if possible a minimal demo of the problem via https://plnkr.co or similar. You can use this template as a starting point: http://plnkr.co/edit/tpl:XXwyUYS6ZL7qVD9I2l0g

What is the expected behavior?

What is the motivation / use case for changing the behavior?

Please tell us about your environment:

• ngx-translate version: 9.0.1

• Angular version: 5.0.3

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]

[alexndreazevedo]

It won't reflect the changes from the Observable AngularFireDatabase.object() because it only takes the first emitted value.

At lib/src/translate.service.ts:267, the TranslationService.getTranslation() uses take(1) from RxJS.

Please, feel free to implement the solution and submit MR.

[kkotak]

This is important to fix as there are scenarios where you may wan to load a LocalStorage based default translation before retrieving the one from Firebase, which could have a visible delay. Also applies to PWA scenario.

[MKhowaja]

It won't reflect the changes from the Observable AngularFireDatabase.object() because it only takes the first emitted value.

At lib/src/translate.service.ts:267, the TranslationService.getTranslation() uses take(1) from RxJS.

Please, feel free to implement the solution and submit MR.

@alexndreazevedo I would like this to be in the library as well. I have a slightly less intrusive solution open in a PR right now. It would be great if either the solution that @kkotak implemented (#777) or the one I implemented (#1028) could be merged

[alexndreazevedo]

@MKhowaja, I'm not actively contributing to the library. Please address it to some active contributor: https://github.com/ngx-translate/core/graphs/contributors