Hands-On Microservices with Kubernetes

Sending link events with NATS

As you may recall, we defined a LinkManagerEvents interface in our object model:

type LinkManagerEvents interface {
        OnLinkAdded(username string, link *Link)
        OnLinkUpdated(username string, link *Link)
        OnLinkDeleted(username string, url string)
}

The LinkManager package receives this event link in its NewLinkManager() method:

func NewLinkManager(linkStore LinkStore,
        socialGraphManager om.SocialGraphManager,
        eventSink om.LinkManagerEvents,
        maxLinksPerUser int64) (om.LinkManager, error) {
        if linkStore == nil {
                return nil, errors.New("link store")
        }

        if eventSink != nil && socialGraphManager == nil { msg := "social graph manager can't be nil if event sink is not nil" return nil, errors.New(msg) } return &LinkManager{ ...