The onerror property of the Notification interface specifies an event listener to receive error events. These events occur when something goes wrong with a Notification (in many cases an error preventing the notification from being displayed.)
The AbstractWorker.onerror property of the AbstractWorker interface represents an EventHandler, that is a function to be called when the error event occurs and bubbles through the Worker.
This example shows an IDBOpenDBRequest.onupgradeneeded block that creates a new object store; it also includes onerror and onabort functions to handle non-success cases.
The following example requests a given record title, onsuccess gets the associated record from the IDBObjectStore (made available as objectStoreTitleRequest.result), updates one property of the record, and then puts the updated record back into the object store. Also included at the bottom is an onerror function that reports what the error was if the request fails. For a full working example, see our To-do Notifications app (view example live.)
In the following code snippet, we open a read/write transaction on our database and add some data to an object store. Note also the functions attached to transaction event handlers to report on the outcome of the transaction opening in the event of success or failure. Note the transaction.onerror = function(event) { }; block, making use of transaction.error to help in reporting what went wrong when the transaction was unsuccessful. For a full working example, see our To-do Notifications app (view example live.)
The onerror property of the SpeechSynthesisUtterance interface represents an event handler that will run when an error occurs that prevents the utterance from being succesfully spoken (when the error event fires.)
The onerror property of the WorkerGlobalScope interface represents an EventHandler to be called when the error event occurs and bubbles through the Worker.
The MediaRecorder.onerror event handler (part of the MediaRecorder API) handles the DOMError event, allowing you to run code in response to fatal errors occurring that prevent media capture.
The onerror property of the SpeechRecognition interface represents an event handler that will run when a speech recognition error occurs (when the error event fires.)