Tracking

The question is asked once. After an answer, iOS shows no dialog again, so permission.blocked() is how an app knows to point the user at Settings instead. Android has no such permission, and the module answers granted there.

Install

npx expo install expo-tracking-transparency

import { Tracking } from '@ng-native/expo/tracking';

The text in Apple's dialog is NSUserTrackingUsageDescription, which the module's config plugin sets from its userTrackingPermission option, with a generic sentence when the option is not given. The plugin also adds Android's AD_ID permission, which the advertising ID needs.

The smallest useful example

import { Component, inject } from '@angular/core';
import { Tracking } from '@ng-native/expo/tracking';

@Component({
  selector: 'app-consent',
  template: `<pressable (press)="allow()"><text>Personalise ads</text></pressable>`,
})
export class Consent {
  private readonly tracking = inject(Tracking);

  protected async allow(): Promise<void> {
    if (await this.tracking.permission.ensure()) {
      console.log('advertising id', this.tracking.advertisingId());
    }
  }
}

What it does

• permission - a Permission: ensure() shows Apple's dialog only if it has not been answered, granted() and blocked() are signals.
• available() - whether the device has the tracking API. Where it does not, the permission answers granted.
• advertisingId() - the IDFA on iOS, the advertising ID on Android. Null on iOS until tracking is allowed, in the simulator, and on Android with ad tracking limited.

Without the module

On iOS and Android, a missing expo-tracking-transparency - never installed, or installed without the app being rebuilt since - throws a MissingModuleError when the service first reaches for it. Its message names the module and the commands that fix it; see Using a module.

On the web, and in a test that provides no fake, the permission is refused and cannot be asked for, available() is false, and advertisingId() is null.

Reference