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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
The definition of 'direction' in that specification.
Recommendation  
Indexed Database API 2.0
The definition of 'direction' in that specification.
Recommendation  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support

24

23 — 24 webkit

12

16

10 — 16 moz

101157
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes22228 Yes

1. partial

See also

Document Tags and Contributors

Contributors to this page: fscholz, jpmedley, arronei, libbymc, chrisdavidmills, teoli
Last updated by: fscholz,