Using EventEmitter for Component Communication in Angular 2

I have a duo of components: AppComp and SimulationComp

AppComp consists of a single function :

createEmptyPromise() {
   return Promise.resolved('')
}

and it showcases the following html structure :

<simulation-comp (simu)='createEmptyPromise()'></simulation-comp>

The Simulation comp manages the (simu) in this manner :

@Output() simu = new EventEmitter()
private eventHandled: boolean = false

// Activated upon pressing a button within the component
whenClicked() {
  this.simu.subscribe(() => {
     this.eventHandled= true
  })
  this.simu.emit()
}

My desire is for eventHandled to transition to true based on the promise delivered by generateEmptyPromise (after handling the emit). However, the current setup isn't achieving that. How can I modify my code to achieve this behavior? Perhaps my approach is incorrect altogether.

Answer â„–1

@Output is used to send values from a child component back to its parent component.

On the other hand, when a parent component needs to communicate with a child component whose template it contains, @Input is necessary. This lets the child component know that the parent will provide values at some point.

To get started, consider using appCmp

<simulation-comp [myinput]='generateEmptyPromise()'></simulation-comp>

Inside the SimulationCmp.ts file, define:

@Input myinput : any //Specify the expected value type here

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