The direction read-only property of the IDBCursor interface is a DOMString that returns the direction of traversal of the cursor (set using IDBObjectStore.openCursor for example). See the Values section below for possible values.
var direction = cursor.direction;
A string (defined by the IDBCursorDirection enum) indicating the direction in which the cursor is traversing the data. Possible values are:
| Value | Description |
|---|---|
next | This direction causes the cursor to be opened at the start of the source. |
nextunique | This direction causes the cursor to be opened at the start of the source. For every key with duplicate values, only the first record is yielded. |
prev | This direction causes the cursor to be opened at the end of the source. |
prevunique | This direction causes the cursor to be opened at the end of the source. For every key with duplicate values, only the first record is yielded. |
In this simple fragment we create a transaction, retrieve an object store, then use a cursor to iterate through all the records in the object store. Within each iteration we log the direction of the cursor, something like this:
prev
Note: we can't change the direction of travel of the cursor using the direction property, as it is read-only. We specify the direction of travel using the 2nd argument of IDBObjectStore.openCursor.
The cursor does not require us to select the data based on a key; we can just grab all of it. Also note that in each iteration of the loop, you can grab data from the current record under the cursor object using cursor.value.foo. For a complete working example, see our IDBCursor example (view example live.)
function backwards() {
list.innerHTML = '';
var transaction = db.transaction(['rushAlbumList'], 'readonly');
var objectStore = transaction.objectStore('rushAlbumList');
objectStore.openCursor(null,'prev').onsuccess = function(event) {
var cursor = event.target.result;
if(cursor) {
var listItem = document.createElement('li');
listItem.innerHTML = '<strong>' + cursor.value.albumTitle + '</strong>, ' + cursor.value.year;
list.appendChild(listItem);
console.log(cursor.direction);
cursor.continue();
} else {
console.log('Entries displayed backwards.');
}
};
}; | Specification | Status | Comment |
|---|---|---|
| Indexed Database API The definition of 'direction' in that specification. | Recommendation | |
| Indexed Database API 2.0 The definition of 'direction' in that specification. | Recommendation |
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | 24
|
12 | 16
|
10
|
15 | 7 |
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | Yes | Yes | Yes | 22 | 22 | 8 | Yes |
IDBDatabase
IDBTransaction
IDBKeyRange
IDBObjectStore
IDBCursor
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/IDBCursor/direction