Notification.onshow

Summary

The onshow property of the Notification interface specifies an event listener to receive show events. These events occur when a Notification is displayed.

Syntax

Notification.onshow = function() { ... };

Specifications

This event handler is no longer listed in the Notifications API spec.

Browser compatibility

Desktop
Mobile

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari
Basic support	5 webkit (see notes) 22	4.0 moz (see notes) 22	Not supported	25	6 (see notes)
`icon`	5 webkit (see notes) 22	4.0 moz (see notes) 22	Not supported	25	Not supported
`noscreen`, `renotify`, `silent`, `sound`, `sticky`	Not supported	Not supported	Not supported	Not supported	Not supported

Feature	Android	Android Webview	Firefox Mobile (Gecko)	Firefox OS	IE Mobile	Opera Mobile	Safari Mobile	Chrome for Mobile
Basic support	?	(Yes)	4.0 moz (see notes) 22	1.0.1 moz (see notes) 1.2	Not supported	?	Not supported	(Yes)
`icon`	?	(Yes)	4.0 moz (see notes) 22	1.0.1 moz (see notes) 1.2	Not supported	?	Not supported	(Yes)
`noscreen`, `renotify`, `silent`, `sound`, `sticky`	Not supported	Not supported	Not supported	Not supported	Not supported	Not supported	Not supported	Not supported

Firefox OS notes

Prior to Firefox 22 (Firefox OS <1.2), the instantiation of a new notification must be done with the navigator.mozNotification object through its createNotification method.
Prior to Firefox 22 (Firefox OS <1.2), the Notification was displayed when calling the show method and supported only the click and close events.
Nick Desaulniers wrote a Notification shim to cover both newer and older implementations.
One particular Firefox OS issue is that you can pass a path to an icon to use in the notification, but if the app is packaged you cannot use a relative path like /my_icon.png. You also can't use window.location.origin + "/my_icon.png" because window.location.origin is null in packaged apps. The manifest origin field fixes this, but it is only available in Firefox OS 1.1+. A potential solution for supporting Firefox OS <1.1 is to pass an absolute URL to an externally hosted version of the icon. This is less than ideal as the notification is displayed immediately without the icon, then the icon is fetched, but it works on all versions of Firefox OS.
When using notifications in a Firefox OS app, be sure to add the desktop-notification permission in your manifest file. Notifications can be used at any permission level, hosted or above.
```
"permissions": {
    "desktop-notification":{}
}
```

Chrome notes

Prior to Chrome 22, the support for notification followed an old prefixed version of the specification and used the navigator.webkitNotifications object to instantiate a new notification.
Prior to Chrome 32, Notification.permission was not supported.

Safari notes

Safari started to support notification with Safari 6, but only on Mac OSX 10.8+ (Mountain Lion).