oncomplete
event handler of the
IDBTransaction
interface handles the complete event, fired when the transaction successfully completes.
As of Firefox 40, IndexedDB transactions have relaxed durability guarantees to increase performance (see
bug 1112702
), which is the same behaviour as other IndexedDB-supporting browsers. Previously in a
readwrite
transaction
IDBTransaction.oncomplete
was fired only when all data was guaranteed to have been flushed to disk. In Firefox 40+ the
complete
event is fired after the OS has been told to write the data but potentially before that data has actually been flushed to disk. The
complete
event may thus be delivered quicker than before, however, there exists a small chance that the entire transaction will be lost if the OS crashes or there is a loss of system power before the data is flushed to disk.
注意
: In Firefox, if you wish to ensure durability for some reason (e.g. you're storing critical data that cannot be recomputed later) you can force a transaction to flush to disk before delivering the
complete
event by creating a transaction using the experimental (non-standard)
readwriteflush
mode (see
IDBDatabase.transaction
.) This is currently experimental, and can only be used if the
dom.indexedDB.experimental
pref is set to
true
in
about:config
.
transaction.oncomplete = function(event) { ... };
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.oncomplete = function(event) { };
block, which reports back when the transaction was successful. For a full working example, see our
待办通知
app (
实时查看范例
)。
// 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.oncomplete) note.innerHTML += '<li>Request successful.</li>'; }; };
| 规范 | 状态 | 注释 |
|---|---|---|
|
索引数据库 API 2.0
The definition of 'oncomplete' in that specification. |
推荐 | |
|
索引数据库 API 草案
The definition of 'oncomplete' in that specification. |
推荐 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
oncomplete
|
Chrome
24
|
Edge 12 |
Firefox
16
|
IE 部分支持 10 | Opera 15 | Safari 7 | WebView Android Yes | Chrome Android Yes | Firefox Android 22 | Opera Android 14 | Safari iOS 8 | Samsung Internet Android Yes |
完整支持
部分支持
要求使用供应商前缀或不同名称。
IDBDatabase
IDBTransaction
IDBKeyRange
IDBObjectStore
IDBCursor
complete
event
IDBTransaction
IDBCursor
IDBCursorSync
IDBCursorWithValue
IDBDatabase
IDBDatabaseException
IDBDatabaseSync
IDBEnvironment
IDBEnvironmentSync
IDBFactory
IDBFactorySync
IDBIndex
IDBIndexSync
IDBKeyRange
IDBObjectStore
IDBObjectStoreSync
IDBOpenDBRequest
IDBRequest
IDBTransactionSync
IDBVersionChangeEvent
IDBVersionChangeRequest