GlobalEventHandlers.onloadstart

The onloadstart property of the GlobalEventHandlers mixin is an EventHandler (en-US) representing the code to be called when the loadstart (en-US) event is raised (when progress has begun on the loading of a resource.)

img.onloadstart = funcRef;

funcRef is the handler function to be called when the resource's loadstart event fires.

<img src="myImage.jpg">

// 'loadstart' fires first, then 'load', then 'loadend'

image.addEventListener('load', function(e) {
  console.log('Image loaded');
});

image.addEventListener('loadstart', function(e) {
  console.log('Image load started');
});

image.addEventListener('loadend', function(e) {
  console.log('Image load finished');
});