Can you explain why addEventListener is not working?

Question

JavaScript

Hello!
I am copying information from one container to another and I need to track the moment when this process is completed completely.
I write like this:

// само копирование
document.getElementById('temp-content').innerHTML = document.getElementById('content').value;

// далее навешиваю обработчик который следит за контейнером
// и (теоретически) должен мне сообщить когда тот будет полностью готов
document.getElementById('temp-content').addEventListener("load", function() {
  alert('Весь HTML-контент загружен в контейнер!');
});

It is the event that is important to me load, since it allows you to track the complete loading of all resources (including images).
Thank you!

Answer 1

Because there is no such event.
HTML is inserted synchronously, no events are needed here.
To track the loading of images, after inserting, you need to select all the images in the desired element, and hang a handler on each.
At the same time, you need to take into account that some image may not load, and some may freeze in the loading state.