Circular dependencies arise when multiple services rely on one another, forming a loop that Angular's dependency injection system cannot resolve. Here's how to address them:
Use Angular's @Inject and forwardRef
// service-a.service.ts
import { Injectable, Inject, forwardRef } from '@angular/core';
import { ServiceB } from './service-b.service';
@Injectable()
export class ServiceA {
constructor(@Inject(forwardRef(() => ServiceB)) private serviceB: ServiceB) {}
}
// service-b.service.ts
import { Injectable, Inject, forwardRef } from '@angular/core';
import { ServiceA } from './service-a.service';
@Injectable()
export class ServiceB {
constructor(@Inject(forwardRef(() => ServiceA)) private serviceA: ServiceA) {}
}