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.
Syntax
var direction = cursor.direction;
Value
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. |
Example
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.');
}
};
};
Specifications
| Specification | Status | Comment |
|---|---|---|
| Indexed Database API 2.0 The definition of 'direction' in that specification. |
Recommendation | |
| Indexed Database API Draft The definition of 'direction' in that specification. |
Recommendation |
Browser compatibility
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
direction | 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.)
