IDBCursor: continue() method
The continue()
method of the IDBCursor
interface advances the cursor to the next position along its direction, to the item
whose key matches the optional key parameter. If no key is specified, the cursor
advances to the immediate next position, based on its direction.
Note: This feature is available in Web Workers
Syntax
js
continue()
continue(key)
Parameters
key
Optional-
The key to position the cursor at.
Return value
None (undefined
).
Exceptions
This method may raise a DOMException
of one of the following types:
TransactionInactiveError
DOMException
-
Thrown if this IDBCursor's transaction is inactive.
DataError
DOMException
-
Thrown if the key parameter has any of the following conditions:
- The key is not a valid key.
- The key is less than or equal to this cursor's position, and the cursor's direction is
next
ornextunique
. - The key is greater than or equal to this cursor's position and this cursor's direction is
prev
orprevunique
.
InvalidStateError
DOMException
-
Thrown if the cursor is currently being iterated or has iterated past its end.
Examples
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. 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 the example live).
js
function displayData() {
const transaction = db.transaction(["rushAlbumList"], "readonly");
const objectStore = transaction.objectStore("rushAlbumList");
objectStore.openCursor().onsuccess = (event) => {
const cursor = event.target.result;
if (cursor) {
const listItem = document.createElement("li");
listItem.textContent = `${cursor.value.albumTitle}, ${cursor.value.year}`;
list.appendChild(listItem);
cursor.continue();
} else {
console.log("Entries all displayed.");
}
};
}
Specifications
Specification |
---|
Indexed Database API 3.0 # ref-for-dom-idbcursor-continue① |
Browser compatibility
BCD tables only load in the browser
See also
- Using IndexedDB
- Starting transactions:
IDBDatabase
- Using transactions:
IDBTransaction
- Setting a range of keys:
IDBKeyRange
- Retrieving and making changes to your data:
IDBObjectStore
- Using cursors:
IDBCursor
- Reference example: To-do Notifications (View the example live).