IDBTransaction: abort event
===========================

The `abort` event is fired when an `IndexedDB` transaction is aborted.

This can happen for any of the following reasons:

* Bad requests, (E.g., trying to add the same key twice, or put the same index key when the key has a uniqueness constraint).
* An explicit `abort()` call.
* An uncaught exception in the request's success/error handler.
* An I/O error (an actual failure to write to disk, for example disk detached, or other OS/hardware failure).
* Quota exceeded.

This non-cancelable event bubbles to the associated `IDBDatabase` object.

Syntax
------

Use the event name in methods like `addEventListener()`, or set an event handler property.


```js
addEventListener("abort", (event) => {});
onabort = (event) => {};
```

Event type
----------

A generic `Event`.

Bubbling
--------

This event bubbles to `IDBDatabase`. The `event.target` property refers to the `IDBTransaction` object that bubbles up.

For more information, see Event bubbling and capture.

Examples
--------

This example opens a database (creating the database if it does not exist), then opens a transaction, adds a listener to the `abort` event, then aborts the transaction to trigger the event.


```js
// Open the database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);

DBOpenRequest.onupgradeneeded = (event) => {
  const db = event.target.result;

  db.onerror = () => {
    console.log("Error creating database");
  };

  // Create an objectStore for this database
  const objectStore = db.createObjectStore("toDoList", {
    keyPath: "taskTitle",
  });

  // define what data items the objectStore will contain
  objectStore.createIndex("hours", "hours", { unique: false });
  objectStore.createIndex("minutes", "minutes", { unique: false });
  objectStore.createIndex("day", "day", { unique: false });
  objectStore.createIndex("month", "month", { unique: false });
  objectStore.createIndex("year", "year", { unique: false });
};

DBOpenRequest.onsuccess = (event) => {
  const db = DBOpenRequest.result;

  // open a read/write db transaction, ready for adding the data
  const transaction = db.transaction(["toDoList"], "readwrite");

  // add a listener for `abort`
  transaction.addEventListener("abort", () => {
    console.log("Transaction was aborted");
  });

  // abort the transaction
  transaction.abort();
};
```


The same example, but assigning the event handler to the `onabort` property:


```js
// Open the database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);

DBOpenRequest.onupgradeneeded = (event) => {
  const db = event.target.result;

  db.onerror = () => {
    console.log("Error creating database");
  };

  // Create an objectStore for this database
  const objectStore = db.createObjectStore("toDoList", {
    keyPath: "taskTitle",
  });

  // define what data items the objectStore will contain
  objectStore.createIndex("hours", "hours", { unique: false });
  objectStore.createIndex("minutes", "minutes", { unique: false });
  objectStore.createIndex("day", "day", { unique: false });
  objectStore.createIndex("month", "month", { unique: false });
  objectStore.createIndex("year", "year", { unique: false });
};

DBOpenRequest.onsuccess = (event) => {
  const db = DBOpenRequest.result;

  // open a read/write db transaction, ready for adding the data
  const transaction = db.transaction(["toDoList"], "readwrite");

  // add a listener for `abort`
  transaction.onabort = (event) => {
    console.log("Transaction was aborted");
  };

  // abort the transaction
  transaction.abort();
};
```

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* Using IndexedDB