Is there any way I can pass dynamic data to a component in Angular?

Question

I am trying to pass data that is dynamic to a child component. But I always get the data as undefined in the child component. Below is what I am doing.

ParentComp

Answer 1

The problem is that the UI thread will render the child component before the subscribe from the observable finished.

you need to do it like this:

import { ChangeDetectorRef } from '@angular/core';

constructor(private ref: ChangeDetectorRef) {}
ngOnInit() {
   this.http.get('url').subscribe(data => { 
     this.results = data;
     this.ref.markForCheck();
   });
}

and in the HTML you have to test the value first.

A little description, the .markForCheck() will refresh the result after the subscribe and will inform all the components which are using this "value" to update its value, including the ng-container. The container would allow rendering the child component now, which will guarantee that the results are not null when the child will be going through its life cycle.