The blocked
handler is executed when an open connection to a database is blocking a versionchange
transaction on the same database.
Bubbles | No |
---|---|
Cancelable | No |
Interface | IDBVersionChangeEvent |
Event handler property | onblocked |
Examples
Using addEventListener()
:
// 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 var 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) => { // Let's try to open the same database with a higher revision version const req2 = indexedDB.open('toDoList', 5); // In this case the onblocked handler will be executed req2.addEventListener('blocked', () => { console.log('Request was blocked'); }); };
Using the onblocked
property:
// 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 var 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) => { // Let's try to open the same database with a higher revision version const req2 = indexedDB.open('toDoList', 5); // In this case the onblocked handler will be executed req2.onblocked = () => { console.log('Request was blocked'); }; };
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
blocked event | Chrome
Full support
24
| Edge Full support 12 | Firefox
Full support
16
| IE Partial support 10 | Opera Full support 15 | Safari Full support 7 | WebView Android
Full support
Yes
| Chrome Android
Full support
25
| Firefox Android Full support 22 | Opera Android Full support 14 | Safari iOS Full support 8 | Samsung Internet Android
Full support
1.5
|
Legend
- Full support
- Full support
- Partial support
- Partial support
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.
See also
- Using IndexedDB
onblocked
event handler property