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What is runInInjectionContext and when do you need to use it?

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01

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Explain injection contexts and when runInInjectionContext is required.

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runInInjectionContext executes a function within an injector's context. This is required when calling APIs like inject(), toSignal(), or effect() asynchronously or outside construction lifecycle boundaries (e.g., inside an event handler or timer callback).

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04

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Executing inject() inside an asynchronous click event handler
import { Component, Injector, runInInjectionContext, inject } from '@angular/core';
import { AnalyticsService } from './analytics.service';

@Component({
  selector: 'app-dynamic-logger',
  standalone: true,
  template: '<button (click)="logClickEvent()">Log Action</button>'
})
export class DynamicLoggerComponent {
  private injector = inject(Injector);

  logClickEvent() {
    runInInjectionContext(this.injector, () => {
      const analytics = inject(AnalyticsService);
      analytics.send('button_click', { time: Date.now() });
    });
  }
}
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