PostHog FE implementation

posthog.service.ts

import { Injectable } from '@angular/core';

import { User } from '../../models/user';
import { environment } from '../../../environments/environment';

import posthog, { JsonType } from 'posthog-js';
import { FeatureFlagsEnum } from '../constants/feature-flags.enum';
import { BehaviorSubject, Observable, of } from 'rxjs';

@Injectable({ providedIn: 'root' })
export class PostHogService {
  init(): void {
    if (!window.Cypress && (environment.production || environment.staging || environment.develop)) {
      posthog.init(environment.POSTHOG_API_KEY, { api_host: 'https://us.i.posthog.com' });
    }
  }

  identify(user: User): void {
    if (window.Cypress) {
      return;
    }
    try {
      posthog.identify(String(user.id), user);

      if (user.company_posthog_groups) {
        user.company_posthog_groups.forEach((group) => {
          posthog.group(user.posthog_group_type, group);
        });
      }
    } catch (error) {
      console.error(error);
    }
  }

  isFeatureEnabled(featureFlag: FeatureFlagsEnum): Observable<boolean> {
    if (window.Cypress) {
      return of(false);
    }
    const isEnabled$ = new BehaviorSubject<boolean | null>(null);
    posthog.onFeatureFlags(() => {
      isEnabled$.next(posthog.isFeatureEnabled(featureFlag));
    });
    return isEnabled$.asObservable();
  }

  getFeatureFlagPayload(featureFlag: FeatureFlagsEnum): JsonType {
    if (window.Cypress) {
      return null;
    }
    return posthog.getFeatureFlagPayload(featureFlag);
  }
}