timers

We are planning to deprecate the use by Firefox add-ons of the techniques described in this document.

Don't use these techniques to develop new add-ons. Use WebExtensions instead.

If you maintain an add-on which uses the techniques described here, consider migrating it to use WebExtensions instead.

Add-ons developed using these techniques might not work with multiprocess Firefox (e10s), which is already the default in Firefox Nightly and Firefox Developer Edition, and will soon be the default in Beta and Release versions of Firefox. We have documentation on making your add-ons multiprocess-compatible, but it will be more future-proof for you to migrate to WebExtensions.

A wiki page containing resources, migration paths, office hours, and more, is available to help developers transition to the new technologies.

Stable

Set one-off and periodic timers.

Globals

Constructors

Functions

setTimeout(callback, ms)

Schedules callback to be called in ms milliseconds. Any additional arguments are passed straight through to the callback.

Parameters

callback : function
Function to be called.

ms : integer
Interval in milliseconds after which the function will be called.

Returns

integer : An ID that can later be used to undo this scheduling, if callback hasn't yet been called.

Example
var { setTimeout } = require("sdk/timers");

setTimeout(function() {
  // do something in 0 ms
}, 0)

clearTimeout(ID)

Given an ID returned from setTimeout(), prevents the callback with the ID from being called (if it hasn't yet been called).

Parameters

ID : integer
An ID returned from setTimeout().

Example
var { setTimeout, clearTimeout } = require("sdk/timers");

var id = setTimeout(function() {
  // do something in 1 sec
}, 1000);

// to stop/cancel this timeout
clearTimeout(id);

setInterval(callback, ms)

Schedules callback to be called repeatedly every ms milliseconds. Any additional arguments are passed straight through to the callback.

Parameters

callback : function
Function to be called.

ms : integer
Interval in milliseconds at which the function will be called.

Returns

integer : An ID that can later be used to unschedule the callback.

Example
var { setInterval } = require("sdk/timers");

setInterval(function() {
  // do something every 1 sec
}, 1000)

clearInterval(ID)

Given an ID returned from setInterval(), prevents the callback with the ID from being called again.

Parameters

ID : integer
An ID returned from setInterval().

Example
var { setInterval, clearInterval } = require("sdk/timers");

var id = setInterval(function() {
  // do something every 1 sec

  // to stop/cancel this interval
  clearInterval(id);
}, 1000);

Document Tags and Contributors

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 Contributors to this page: wbamberg, evold
 Last updated by: wbamberg,