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    IDBCursor.direction

    The direction 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

    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.
    Candidate Recommendation  

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
    Basic support 23webkit
    24
    10 moz
    16.0 (16.0)
    10, partial 15 7.1
    Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
    Basic support 4.4 22.0 (22.0) 1.0.1 10 22 Not supported

    See also

    Document Tags and Contributors

    Contributors to this page: teoli, chrisdavidmills
    Last updated by: teoli,