luet/vendor/github.com/mudler/go-pluggable/bus.go
2020-11-13 19:50:10 +01:00

74 lines
1.9 KiB
Go

// Copyright © 2020 Ettore Di Giacinto <mudler@mocaccino.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see <http://www.gnu.org/licenses/>.
package pluggable
import (
"sync"
"github.com/chuckpreslar/emission"
"github.com/codegangsta/inject"
)
// Bus represent the bus event system
type Bus struct {
inject.Injector
emission.Emitter
sync.Mutex
}
// NewBus returns a new Bus instance
func NewBus() *Bus {
return &Bus{
Injector: inject.New(),
Emitter: *emission.NewEmitter(),
}
}
// Listen Binds a callback to an event, mapping the arguments on a global level
func (a *Bus) Listen(event EventType, listener interface{}) *Bus {
a.Lock()
defer a.Unlock()
a.On(string(event), func() { a.Invoke(listener) })
return a
}
// Publish publishes an event, it does accept only the event as argument, since
// the callback will have access to the service mapped by the injector
func (a *Bus) Publish(e *Event) *Bus {
a.Lock()
defer a.Unlock()
a.Map(e)
a.Emit(string(e.Name))
return a
}
// OnlyOnce Binds a callback to an event, mapping the arguments on a global level
// It is fired only once.
func (a *Bus) OnlyOnce(event EventType, listener interface{}) *Bus {
a.Lock()
defer a.Unlock()
a.Once(string(event), func() { a.Invoke(listener) })
return a
}
func (a *Bus) propagateEvent(p Plugin) func(e *Event) {
return func(e *Event) {
resp, _ := p.Run(*e)
a.Map(&resp)
a.Emit(p.Name)
}
}