Question

I use two different events for the callback to respond when the IndexedDB transaction finishes or is successful:

Let’s say… db : IDBDatabase object, tr : IDBTransaction object, os : IDBObjectStore object

tr = db.transaction(os_name,'readwrite');
os = tr.objectStore();

case 1 :

r = os.openCursor();
r.onsuccess = function() {
    if(r.result){
        callback_for_result_fetched();
        r.result.continue;
    } else {
        callback_for_transaction_finish();
    }
}

case 2:

tr.oncomplete = callback_for_transaction_finish();

It is a waste if both of them work similarly. So can you tell me, is there any difference between them?

Answer 1

While it’s true these callbacks function similarly they are not the same: the difference between onsuccess and oncomplete is that transactions complete but requests, which are made on those transactions, are successful.

oncomplete is only defined in the spec as related to a transaction. A transaction doesn’t have an onsuccess callback.