IDBVersionChangeEvent
The IDBVersionChangeEvent
interface of the IndexedDB API indicates that the version of the database has changed, as the result of an onupgradeneeded
event handler function.
Note: This feature is available in Web Workers
Constructor
IDBVersionChangeEvent()
-
Creates and returns a new
IDBVersionChangeEvent
object which is used to represent when a version of the database has changed.
Properties
Also inherits properties from its parent, Event
interface.
IDBVersionChangeEvent.oldVersion
Read only-
Returns the old version of the database.
IDBVersionChangeEvent.newVersion
Read only-
Returns the new version of the database.
Deprecated properties
IDBVersionChangeEvent.version
Read only-
The new version of the database in a
versionchange
transaction.Warning: While this property is still implemented in older browsers, the latest specification replaces it with the
oldVersion
andnewVersion
attributes. See the compatibility table to know what browsers support them.
Methods
No specific method, but inherits properties from its parent, Event
interface.
Example
In the following code snippet, we make a request to open a database, and include handlers for the success and error cases. Upon a version change (after an upgradeneeded
event), the success
event will implement the IDBVersionChangeEvent
interface. For a full working example, see our To-do Notifications app (view example live.)
var note = document.querySelector("ul");
// In the following line, you should include the prefixes of implementations you want to test.
window.indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
// DON'T use "var indexedDB = ..." if you're not in a function.
// Moreover, you may need references to some window.IDB* objects:
window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange || window.msIDBKeyRange;
// (Mozilla has never prefixed these objects, so we don't need window.mozIDB*)
// Let us open version 4 of our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);
// these two event handlers act on the database being opened successfully, or not
DBOpenRequest.onerror = function(event) {
note.innerHTML += '<li>Error loading database.</li>';
};
DBOpenRequest.onsuccess = function(event) {
note.innerHTML += '<li>Database initialized.</li>';
// store the result of opening the database in the db variable. This is used a lot later on, for opening transactions and suchlike.
db = DBOpenRequest.result;
};
Specifications
Specification |
---|
Indexed Database API 3.0 # events |
Browser compatibility
BCD tables only load in the browser
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
- IDBDatabase.onversionchange
- Reference example: To-do Notifications (view example live.)