plugeth/eventer/eventer.go

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package eventer
// Basic receiver interface.
type Receiver interface {
Send(Event)
}
// Receiver as channel
type Channel chan Event
func (self Channel) Send(ev Event) {
self <- ev
}
// Receiver as function
type Function func(ev Event)
func (self Function) Send(ev Event) {
self(ev)
}
type Event struct {
Type string
Data interface{}
}
type Channels map[string][]Receiver
type EventMachine struct {
channels Channels
}
func New() *EventMachine {
return &EventMachine{
channels: make(Channels),
}
}
func (self *EventMachine) add(typ string, r Receiver) {
self.channels[typ] = append(self.channels[typ], r)
}
// Generalised methods for the known receiver types
// * Channel
// * Function
func (self *EventMachine) On(typ string, r interface{}) {
if eventFunc, ok := r.(func(Event)); ok {
self.RegisterFunc(typ, eventFunc)
} else if eventChan, ok := r.(Channel); ok {
self.RegisterChannel(typ, eventChan)
} else {
panic("Invalid type for EventMachine::On")
}
}
func (self *EventMachine) RegisterChannel(typ string, c Channel) {
self.add(typ, c)
}
func (self *EventMachine) RegisterFunc(typ string, f Function) {
self.add(typ, f)
}
func (self *EventMachine) Register(typ string) Channel {
c := make(Channel, 1)
self.add(typ, c)
return c
}
func (self *EventMachine) Post(typ string, data interface{}) {
if self.channels[typ] != nil {
ev := Event{typ, data}
for _, receiver := range self.channels[typ] {
// Blocking is OK. These are internals and need to be handled
receiver.Send(ev)
}
}
}