Bug(transloco): cant provide DefaultHandler

[Pascal Kania]

Is there an existing issue for this?

• I have searched the existing issues

Which Transloco package(s) are the source of the bug?

Transloco

Is this a regression?

Yes

Current behavior

if i want to initialize transloco via a useFactory method in angular 16 then i can't set a provider via provideTranslocoMissingHandler(DefaultHandler) because it is not exported via the index.ts

for example:

providers: [
    {
      provide: TRANSLOCO_CONFIG,
      useFactory: (environment: Environment) =>
        translocoConfig({
          availableLangs: availableLanguages,
          defaultLang: DEFAULT_LANGUAGE,
          prodMode: environment.production,
          fallbackLang: DEFAULT_LANGUAGE,
          missingHandler: {
            useFallbackTranslation: true
          },
          reRenderOnLangChange: true
        }),
      deps: [ENVIRONMENT]
    },
    { provide: TRANSLOCO_LOADER, useClass: TranslocoHttpLoader },
    provideTranslocoTranspiler(DefaultTranspiler),
    provideTranslocoMissingHandler(DefaultHandler) <--- i cant use the DefaultHandler here

i got the following error message:

transloco.module.ts:5:0-81 - Error: Module not found: Error: Package path ./lib/transloco-missing-handler is not exported from package ... @ngneat\transloco (see exports field in @ngneat\transloco\package.json)

Expected behavior

it should be possible to use the DefaultHandler with provideTranslocoMissingHandler(DefaultHandler)

Please provide a link to a minimal reproduction of the bug, if you won't provide a link the issue won't be handled.

https://codesandbox.io/s/ngneat-transloco-forked-gjdn5d?file=/src/app/app.config.ts

Transloco Config

-

Please provide the environment you discovered this bug in

Transloco: 5.0.7
Angular: 16.1.9
Node: v18.12.0
Package Manager: npm(8.19.2)
OS: Windows 10

Browser

Chrome

Additional context

I would like to make a pull request for this bug

No

[Pascal Kania]

i also cant use the DefaultInterceptor

i found a way for using the default providers over

provideTransloco({
      config: undefined as any, <-- but this is also not a clean approach.
      loader: TranslocoHttpLoader
    }),

[Shahar Kazaz]

@pascal-kania The DefaultMissingHandler is like the name states is the default handler provided by Transloco, you get it OOTB, the same goes for the DefaultInterceptor 🙂
You should you the provideTransloco function.
Here is the relevant snippet from transloco.providers.ts file:

export function provideTransloco(options: TranslocoOptions) {
  const providers: EnvironmentProviders[] = [
    provideTranslocoTranspiler(DefaultTranspiler),
    provideTranslocoMissingHandler(DefaultHandler),
    provideTranslocoInterceptor(DefaultInterceptor),
    provideTranslocoFallbackStrategy(DefaultFallbackStrategy),
  ];

  if (options.config) {
    providers.push(provideTranslocoConfig(options.config));
  }

  if (options.loader) {
    providers.push(provideTranslocoLoader(options.loader));
  }

  return providers;
}

If I'm missing something please feel free to further explain and share more information as to what you are trying to do.

[Daniel Beckmann]

We are facing the same issue in our project, where we have provided TRANSLOCO_CONFIG by using useFactory. The reason is, that we rely on another injected service (UserPreferenceService) to provide us the default language by looking it up in the local storage.

{
  provide: TRANSLOCO_CONFIG,
  deps: [UserPreferenceService],
  useFactory: (userPreferenceService: UserPreferenceService) => {
    return translocoConfig({
      availableLangs: config.languages,
      defaultLang: userPreferenceService.getPreferredLanguage(
        config.languages,
        config.defaultLanguage
      ),
      prodMode: config.prodMode,
    });
  },
},

So we cannot use provideTransloco, as UserPreferenceService needs to be injected before. Maybe this is not something which can be solved in transloco @shaharkazaz ?

The alternative that I see currently is to replace the UserPreferenceService with a plain helper method, which does not need DI, like:

provideTransloco({
  config: {
      availableLangs: config.languages,
      defaultLang: getPreferredLanguage(config.languages, config.defaultLanguage),
      prodMode: config.prodMode,
    },
  loader: TranslocoHttpLoader
})

[Shahar Kazaz]

These default handlers are now exposed in v7.3.0