alfresco-ng2-components/lib/core/feature-flags

@alfresco/adf-core/feature-flags

Secondary entry point of @alfresco/adf-core. It can be used by importing from @alfresco/adf-core/feature-flags.

Feature flags (aka feature toggles) are a concept that allow product owners to control the availability of a feature in a particular environment. A product manager may use feature flags to hide a feature that isn't complete yet, roll out a feature to a select set of end-users in order to gather feedback, or coordinate a feature "go live" with marketing and other departments. From a developer perspective, feature flags are an important tool that allows them to continually commit their code even if a feature is not complete, thus a proper feature flag capability is essential to a functional continuous delivery model.

Because this library system is BE/Framework agnostic, it's required to implement the service that manages the retrieval of FeatureFlags and provide it to the AppModule:

@NgModule({
    declarations: [AppComponent],
    providers: [
          { provide: OverridableFeaturesServiceToken, useClass: <YourCustomFeaturesService> },
          { provide: FeaturesServiceToken, useExisting: OverridableFeaturesServiceToken },
          { provide: FeaturesServiceConfigToken, useValue: <CustomConfiguration> }
    ],
    bootstrap: [AppComponent],
})
export class AppModule {}

<YourCustomFeaturesService> is a service that implements the IFeaturesService interface:

interface IFeaturesService<T = FlagChangeset> {
  init(): Observable<T>;
  isOn$(key: string): Observable<boolean>;
  isOff$(key: string): Observable<boolean>;
  getFlags$(): Observable<T>;
}

A FlagChangeset is an Object in which keys are Feature Flag names, and values are the current and previous enabled status for that particular flag. The previous status can be null.

interface FlagChangeset {
  [key: string]: {
    current: boolean;
    previous: boolean | null;
  };
}

Optionally, is possible to provide a <CustomConfiguration>

{
    storageKey?: string;
    helperExposeKeyOnDocument?: string;
}

storageKey: Local Storage key to save feature flags (default: 'feature-flags') helperExposeKeyOnDocument: browser document key to add commands to enable or disable feature flags from the browser console.

Furher reading: https://hyland.atlassian.net/wiki/spaces/HXP/pages/1308017277/Studio+Management+of+Feature+Flags https://hyland.atlassian.net/wiki/spaces/HXP/pages/1308031390/Developing+frontend+apps+libs+e2es+with+feature+flags