Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The mozbrowserloadstart event is fired when the browser <iframe> starts to load a new page.

This can be used when the embedder wants to start spinning a loading indicator, or update the UI in some other way to indicate loading has started.

General info

Specification
Non standard
Interface
CustomEvent
Bubbles
Yes
Cancelable
Yes
Target
<iframe>
Default Action
None

Properties

Property Type Description
target Read only EventTarget The event target (the topmost target in the DOM tree).
type Read only DOMString The type of event.
bubbles Read only Boolean Whether the event normally bubbles or not.
cancelable Read only Boolean Whether the event is cancellable or not.

Example

In this example the mozbrowserloadend and mozbrowserloadstart events are used to change the icon shown on the stop/reload button between stop (x) and reload (R), as appropriate.

var browser = document.querySelector("iframe");

browser.addEventListener('mozbrowserloadstart',function() {
  stopReload.textContent = 'x';
});

browser.addEventListener('mozbrowserloadend',function() {
  stopReload.textContent = 'R';
});

See also