Subscription

go-conflux-sdk functional-reactive nature makes it really simple to setup observers that notify subscribers of events taking place on the blockchain.

To receive all new blocks head as they are added to the blockchain:

channel := make(chan types.BlockHeader, 100)
subscription, err := client.SubscribeNewHeads(channel)

To receive all new epochs as they are added to the blockchain:

channel := make(chan types.WebsocketEpochResponse, 100)
subscription, err := client.SubscribeEpochs(channel)

To receive all new logs as they are emited on the blockchain:

channel := make(chan types.SubscriptionLog, 100)
subscription, err := client.SubscribeLogs(channel, types.LogFilter{...})

The new happened event will be sent to channel, and an error signal will be sent to subscription.Err() when a subscription error occurs. Normally handle the channels like:

errorchan := sub.Err()
for {
	select {
	case err = <-errorchan:
		// handle when error
	case xxx := <-channel:
		// handle received signal
	}
}

Subscriptions should always be cancelled when no longer required:

subscription.unsubscribe();

It should be noted that when subscribing logs, a SubscribeLogs object is received. It has two fields Log and ChainRerog, one of them must be nil and the other not. When Log is not nil, it means that a Log is received. When field ChainReorg is not nil, that means chainreorg occurs. That represents the log related to epoch greater than or equal to ChainReog.RevertTo will become invalid, and the Dapp needs to be dealt with at the business level.

Please find Publish-Subscribe API documentation from https://developer.confluxnetwork.org/conflux-doc/docs/pubsub