Child Component Reference vs EventEmitter in Angular

Both approaches have their place in Angular development, but they serve different architectural purposes:

Child Component Reference (ViewChild)

@ViewChild('chatComponent') chatComponent!: ChatComponent;

clearChat(): void {
  if (this.chatComponent) {
    this.chatComponent.resetChat();
  }
}

Advantages:

• Direct communication: Straightforward method calls
• Simpler syntax: Less boilerplate code
• Type safety: Full access to child's public API
• Imperative control: Useful for direct manipulation

Disadvantages:

• Tight coupling: Parent depends on child's implementation
• Less reusable: Components become more interdependent
• Harder to test: Mocking becomes more complex
• Less reactive: Doesn't follow Angular's data flow philosophy

EventEmitter Approach

// Child component
@Output() resetRequested = new EventEmitter<void>();

// When to emit
requestReset(): void {
  this.resetRequested.emit();
}

// Parent template
<app-chat (resetRequested)="handleReset()"></app-chat>

Advantages:

• Loose coupling: Child doesn't need to know about parent
• More reusable: Components work independently
• Easier testing: Components can be isolated
• Reactive pattern: Follows Angular's recommended data flow
• Better encapsulation: Internal component state is protected

Disadvantages:

• More verbose: Requires additional setup
• Indirect flow: Can be harder to trace execution path
• Asynchronous: Event-based rather than direct method calls

When to Use Each

Use ViewChild when:

• The parent-child relationship is tightly defined
• You need direct access to the child's DOM or methods
• Components are always used together and won't be reused separately

Use EventEmitter when:

• You want loosely coupled components
• Components will be reused in different contexts
• Following reactive programming patterns
• Building a component library