Subscribe to channel
Creates an event handler that listens to changes.
- By default, Broadcast and Presence are enabled for all projects.
- By default, listening to database changes is disabled for new projects due to database performance and security concerns. You can turn it on by managing Realtime's replication.
- You can receive the "previous" data for updates and deletes by setting the table's
REPLICA IDENTITYtoFULL(e.g.,ALTER TABLE your_table REPLICA IDENTITY FULL;). - Row level security is not applied to delete statements. When RLS is enabled and replica identity is set to full, only the primary key is sent to clients.
Parameters
type
REQUIRED
"broadcast"filter
REQUIRED
objectevent
REQUIRED
stringcallback
REQUIRED
function
supabase
.channel('room1')
.on('broadcast', { event: 'cursor-pos' }, payload => {
console.log('Cursor position received!', payload)
})
.subscribe((status) => {
if (status === 'SUBSCRIBED') {
channel.send({
type: 'broadcast',
event: 'cursor-pos',
payload: { x: Math.random(), y: Math.random() },
})
}
})