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.
A string (defined by the IDBCursorDirection
enum) indicating the direction in which the cursor is traversing the data. Possible values are:
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.textContent = '';
const transaction = db.transaction(['rushAlbumList'], 'readonly');
const objectStore = transaction.objectStore('rushAlbumList');
objectStore.openCursor(null,'prev').onsuccess = function(event) {
const cursor = event.target.result;
if(cursor) {
const 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.');
}
};
};