source
只读特性在
IDBRequest
interface returns the source of the request, such as an Index or an object store. If no source exists (such as when calling
indexedDB.open
), it returns null.
var IDBIndex = request.source; var IDBCursor = request.source; var IDBObjectStore = request.source;
An object representing the source of the request, such as an
IDBIndex
,
IDBObjectStore
or
IDBCursor
.
The following example requests a given record title,
onsuccess
gets the associated record from the
IDBObjectStore
(made available as
objectStoreTitleRequest.result
), updates one property of the record, and then puts the updated record back into the object store in another request. The source of the 2nd request is logged to the developer console. For a full working example, see our
待办通知
app (
实时查看范例
)。
var title = "Walk dog";
// Open up a transaction as usual
var objectStore = db.transaction(['toDoList'], "readwrite").objectStore('toDoList');
// Get the to-do list object that has this title as its title
var objectStoreTitleRequest = objectStore.get(title);
objectStoreTitleRequest.onsuccess = function() {
// Grab the data object returned as the result
var data = objectStoreTitleRequest.result;
// Update the notified value in the object to "yes"
data.notified = "yes";
// Create another request that inserts the item
// back into the database
var updateTitleRequest = objectStore.put(data);
// Log the source of this request
console.log("The source of this request is " + updateTitlerequest.source);
// When this new request succeeds, run the displayData()
// function again to update the display
updateTitleRequest.onsuccess = function() { displayData(); };
};
| 规范 | 状态 | 注释 |
|---|---|---|
|
索引数据库 API 2.0
The definition of 'source' in that specification. |
推荐 | |
|
索引数据库 API 草案
The definition of 'source' in that specification. |
推荐 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
source
|
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
IDBRequest
error
onerror
onsuccess
readyState
result
source
transaction
IDBCursor
IDBCursorSync
IDBCursorWithValue
IDBDatabase
IDBDatabaseException
IDBDatabaseSync
IDBEnvironment
IDBEnvironmentSync
IDBFactory
IDBFactorySync
IDBIndex
IDBIndexSync
IDBKeyRange
IDBObjectStore
IDBObjectStoreSync
IDBOpenDBRequest
IDBTransaction
IDBTransactionSync
IDBVersionChangeEvent
IDBVersionChangeRequest