web3.eth.subscribe Migration Guide
Breaking Changes
New Block Headers event
In 1.x, web3.eth.subscribe('newBlockHeaders')
was used to subscribe to new block headers.
In 4.x, either web3.eth.subscribe('newHeads')
or web3.eth.subscribe('newBlockHeaders')
can be used to subscribe to new block headers.
web3.eth.clearSubscriptions
In 1.x, web3.eth.clearSubscriptions
returns true
on success.
In 4.x, web3.eth.clearSubscriptions
returns an Array of subscription ids
.
// in 1.x
var subscription = web3.eth.subscribe('newBlockHeaders', function (error, result) {
if (!error) console.log(result);
});
web3.eth.clearSubscriptions(function (error, success) {
console.log(success); // true
});
// in 4.x
const subscription = await web3.eth.subscribe('newHeads');
subscription.unsubscribe().then(
console.log(), // [...] Array of subsription ids
);