IDBCursor.direction

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.

Note: This feature is available in Web Workers.

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

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
directionChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Partial support 10Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesFirefox Android Full support 22Opera Android Full support 14Safari iOS Full support 8Samsung 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