files/en-us/mozilla/add-ons/webextensions/api/alarms/onalarm/index.md
Fired when any alarm set by the extension goes off.
browser.alarms.onAlarm.addListener(listener)
browser.alarms.onAlarm.removeListener(listener)
browser.alarms.onAlarm.hasListener(listener)
Events have three functions:
addListener(listener)
removeListener(listener)
listener argument is the listener to remove.hasListener(listener)
listener is registered for this event. Returns true if it is listening, false otherwise.listener
alarm
Alarm.name to figure out which alarm fired.Handle an alarm going off:
function handleAlarm(alarmInfo) {
console.log(`on alarm: ${alarmInfo.name}`);
}
browser.alarms.onAlarm.addListener(handleAlarm);
{{WebExtExamples}}
{{Compat}}
[!NOTE] This API is based on Chromium's
chrome.alarmsAPI.