JavaScript Internals (521 Qs)•Part 2: Promises, Callbacks, Async & Strict Mode (54 - 103)
What are the events available for server sent events
Below are the list of events available for server sent events
| Event | Description |
|---|---|
| onopen | It is used when a connection to the server is opened |
| onmessage | This event is used when a message is received |
| onerror | It happens when an error occurs |
Practical Code Example
javascript
const source = new EventSource('/events');
// Built-in standard events:
source.onopen = () => console.log('Connection opened');
source.onmessage = (event) => console.log('Default message:', event.data);
source.onerror = (error) => console.log('Connection error');
// Custom named events from server ('event: priceChange'):
source.addEventListener('priceChange', (event) => {
console.log('Custom event triggered:', event.data);
});