Angular2 - 从另一个独立组件调用 function。 基本上，从外部组件调用 function

Question

I'm loading in a component (Component1) another standalone component(Component2) that contains a form.

Imagine you have made a form component and I want to integrate it in my component and trigger the submit function you have written, without clicking on your submit Button.

The submit button on this form triggers a function to save data:

submitData(newUserForm: NgForm)

The main component (Component1) also has a submit button. What I want is to remove the submit button from Component2 and trigger the submit function when I click on submit from Component1.

Something like:

<button type="button" class="submit" (click)="saveData()">{{ Save }}</button>

saveData() {
     Component2.submitData(data);
}

ViewChild won't work since the 2 components are not part of the same component. Also, output won't work.

What options do I have to call the function from outside Component2?

I hope you can help.

Thank you.

Regards, AG

Answer 1

Without much context, I think you need a service to do this. If there's no relation between those 2 components, why would you call a function from component 2? Put save logic into a service and inject it on whatever component you need it.

Answer 2

Use a service here

SomeService

private value: Subject<string> = new Subject<string>();

// return the Subject as an Observable in order to be able to subscribe to it
public get theValue(): Observable<string> {
    return this.value.asObservable();
}

// set the current value
public set theValue(value: string) {
    this.value.next(value);
}

Component 2 TS

constructor(private someService: SomeService){

}

ngOnInit(): void {
    // subscribe to the value and refresh the local variable whenever it changes
    this.someService.theValue.subscribe( value => {
        console.log('Info from Component 1: ' + value;

        if (value === 'Saved') {
            Component2.submitData(data);
        }
    });
}

Component 1 TS

constructor(private someService: SomeService){
}

saveData(): void {
    this.someService.theValue = 'Saved';
}

Answer 3

This is about the component interaction, you need to use service for communicating between two different components. Main thing is the dependency injection of Angular.

Simply you can use Subject.