TypeError: Cannot set property 'checked' of null

@leonardofmed wrote:

I want to dynamically activate some checkboxes when the user enters the page. For this I am saving the IDs of the HTML checkbox elements in a service. When the user enters the page, this service is accessed and returns an array with these IDs. The active elements are checked in each loop.

this.platform.ready().then(() => {
	let checboxState = this.service.checboxState;
	if (checboxState !== undefined && checboxState.length > 0) {
		checboxState.forEach(checbox => {
			let element = document.getElementById(checbox.id) as HTMLInputElement;
			element.checked = true;
		});
	}
});

But I’m getting this error:

Uncaught (in promise): TypeError: Cannot set property ‘checked’ of null

Which can be a indicator that Javascript function is firing before DOM is loaded. If that is the case, why platform.ready() isn’t working? I tried also with:

• document.addEventListener("DOMContentLoaded",() => {}
• window.onload = () => {}

but no success.

---

I managed to make the function work by adding a setTimeout() before the function, so how do I correctly wait the HTML elements to load before firing the JS function?

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