OpenLayers map not appearing in Angular dialog without setTimeout

Question

I am using OpenLayers to display a map in an Angular application. The map is inside a dialog element and is not appearing when the dialog is opened. However, if I use a setTimeout function to delay setting the target for the map, the map does appear. I do not understand why this is happening. What is the best way to avoid using setTimeout?

setTimeout(() => {
  this.map.setTarget('location_map');
}, 500);

Answer 1

Most likely, the target of the map is set before the dialog element is even created, however it is hard to tell without your code. If the element already exists, and you modify the size or its visibility to show it, you should update the size of the map using map.updateSize()

Answer 2

I understood the issue and i found a solution:

Issue: The DOM element for the map (the element with the ID "location_map") is not yet present in the DOM when i try to set the target for the map.

Solution: To avoid using setTimeout i use Angular's lifecycle hooks to set the target for the map after the component has finished rendering.

I use the ngAfterViewInit hook to set the target for the map after the component's view has been fully initialized.

something like:

import { Component, AfterViewInit } from '@angular/core';

@Component({
  // component metadata here
})
export class MyComponent implements AfterViewInit {
  map: any;

  ngAfterViewInit() {
    // Initialize the map here, then set the target once the map is ready
    this.map = new Map({
      // map options here
    });
    this.map.setTarget('location_map');
  }
}