IDBDatabase.onversionchange
The onversionchange
event handler of the IDBDatabase
interface handles the versionchange event, fired when a database structure change (IDBOpenDBRequest.onupgradeneeded
event or IDBFactory.deleteDatabase
) was requested elsewhere (most probably in another window/tab on the same computer).
This is different from the versionchange
transaction (but it is related).
Syntax
db.onversionchange = function() { ... }
Example
This example shows an IDBOpenDBRequest.onupgradeneeded
block that creates a new object store; it also includes onerror
and onabort
functions to handle non-success cases, and an onversionchange function to notify when a database structure change has occurred.
request.onupgradeneeded = function(event) { var db = event.target.result; db.onerror = function(event) { note.innerHTML += '<li>Error opening database.</li>'; }; db.onabort = function(event) { note.innerHTML += '<li>Database opening aborted!</li>'; }; // Create an objectStore for this database var objectStore = db.createObjectStore("toDoList", { keyPath: "taskTitle" }); // define what data items the objectStore will contain objectStore.createIndex("hours", "hours", { unique: false }); objectStore.createIndex("minutes", "minutes", { unique: false }); objectStore.createIndex("day", "day", { unique: false }); objectStore.createIndex("month", "month", { unique: false }); objectStore.createIndex("year", "year", { unique: false }); objectStore.createIndex("notified", "notified", { unique: false }); note.innerHTML += '<li>Object store created.</li>'; db.onversionchange = function(event) { note.innerHTML += '<li>a database change has occurred; you should refresh this browser window, or close it down and use the other open version of this application, wherever it exists.</li>'; }; };
Specifications
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'onversionchange' in that specification. |
Editor's Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 23webkit 24 |
10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
Available in workers | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | 4.4 | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 |
Available in workers | (Yes) | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
See also
- Using IndexedDB
- Starting transactions:
IDBDatabase
- Using transactions:
IDBTransaction
- Setting a range of keys:
IDBKeyRange
- Retrieving and making changes to your data:
IDBObjectStore
- Using cursors:
IDBCursor
- Reference example: To-do Notifications (view example live.)
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/idbdatabase/onversionchange