files/en-us/web/api/idbrequest/source/index.md
{{ APIRef("IndexedDB") }} {{AvailableInWorkers}}
The source read-only property of the
{{domxref("IDBRequest")}} interface returns the source of the request, such as an
Index or an object store. If no source exists (such as when calling
{{domxref("IDBFactory.open")}}), it returns null.
An object representing the source of the request, such as an {{domxref("IDBIndex")}}, {{domxref("IDBObjectStore")}} or {{domxref("IDBCursor")}}.
The following example requests a given record title, onsuccess gets the
associated record from the {{domxref("IDBObjectStore")}} (made available
as objectStoreTitleRequest.result), updates
one property of the record, and then puts the updated record back into the object
store in another request. The source of the 2nd request is logged to the developer
console. For a full working example, see our To-do Notifications app (View the example live).
const title = "Walk dog";
// Open up a transaction as usual
const objectStore = db
.transaction(["toDoList"], "readwrite")
.objectStore("toDoList");
// Get the to-do list object that has this title as its title
const objectStoreTitleRequest = objectStore.get(title);
objectStoreTitleRequest.onsuccess = () => {
// Grab the data object returned as the result
const data = objectStoreTitleRequest.result;
// Update the notified value in the object to "yes"
data.notified = "yes";
// Create another request that inserts the item
// back into the database
const updateTitleRequest = objectStore.put(data);
// Log the source of this request
console.log(`The source of this request is ${updateTitleRequest.source}`);
// When this new request succeeds, run the displayData()
// function again to update the display
updateTitleRequest.onsuccess = () => {
displayData();
};
};
{{Specifications}}
{{Compat}}