The onerror
event handler of the IDBTransaction
interface handles the error event, fired when a request returns an error and bubbles up to the transaction object.
Note: Consider using IDBTransaction.onabort
instead to handle non- successful completion of the transaction.
Syntax
transaction.onerror = function(event) { ... };
Example
In the following code snippet, we open a read/write transaction on our database and add some data to an object store. Note also the functions attached to transaction event handlers to report on the outcome of the transaction opening in the event of success or failure. Note the transaction.onerror = function(event) { };
block, making use of transaction.error
to help in reporting what went wrong when the transaction was unsuccessful. For a full working example, see our To-do Notifications app (view example live.)
// Let us open our database var DBOpenRequest = window.indexedDB.open("toDoList", 4); DBOpenRequest.onsuccess = function(event) { note.innerHTML += '<li>Database initialised.</li>'; // store the result of opening the database in the db variable. // This is used a lot below db = DBOpenRequest.result; // Run the addData() function to add the data to the database addData(); }; function addData() { // Create a new object ready for being inserted into the IDB var newItem = [ { taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: "December", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["toDoList"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerHTML += '<li>Transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerHTML += '<li>Transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectStore = transaction.objectStore("toDoList"); // add our newItem object to the object store var objectStoreRequest = objectStore.add(newItem[0]); objectStoreRequest.onsuccess = function(event) { // report the success of the request (this does not mean the item // has been stored successfully in the DB - for that you need transaction.onsuccess) note.innerHTML += '<li>Request successful.</li>'; }; };
Specification
Specification | Status | Comment |
---|---|---|
Indexed Database API 2.0 The definition of 'onerror' in that specification. |
Recommendation | |
Indexed Database API Draft The definition of 'onerror' in that specification. |
Recommendation |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
onerror | Chrome
Full support
24
| Edge Full support 12 | Firefox
Full support
16
| IE Partial support 10 | Opera Full support 15 | Safari Full support 7 | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 22 | Opera Android Full support 14 | Safari iOS Full support 8 | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- Partial support
- Partial support
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.
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.)
error
event