Improve listeners and handlers (#350)

* improve listeners and handlers

* add to route handlers

* separate create/delete/update events

* removed useless interface

api/server/listeners.go

@@ -0,0 +1,82 @@
+package server
+
+import (
+	"context"
+	"github.com/iron-io/functions/api/ifaces"
+	"github.com/iron-io/functions/api/models"
+)
+
+// AddAppCreateListener adds a listener that will be notified on App created.
+func (s *Server) AddAppCreateListener(listener ifaces.AppCreateListener) {
+	s.AppCreateListeners = append(s.AppCreateListeners, listener)
+}
+
+// AddAppUpdateListener adds a listener that will be notified on App updated.
+func (s *Server) AddAppUpdateListener(listener ifaces.AppUpdateListener) {
+	s.AppUpdateListeners = append(s.AppUpdateListeners, listener)
+}
+
+// AddAppDeleteListener adds a listener that will be notified on App deleted.
+func (s *Server) AddAppDeleteListener(listener ifaces.AppDeleteListener) {
+	s.AppDeleteListeners = append(s.AppDeleteListeners, listener)
+}
+
+func (s *Server) FireBeforeAppCreate(ctx context.Context, app *models.App) error {
+	for _, l := range s.AppCreateListeners {
+		err := l.BeforeAppCreate(ctx, app)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *Server) FireAfterAppCreate(ctx context.Context, app *models.App) error {
+	for _, l := range s.AppCreateListeners {
+		err := l.AfterAppCreate(ctx, app)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *Server) FireBeforeAppUpdate(ctx context.Context, app *models.App) error {
+	for _, l := range s.AppUpdateListeners {
+		err := l.BeforeAppUpdate(ctx, app)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *Server) FireAfterAppUpdate(ctx context.Context, app *models.App) error {
+	for _, l := range s.AppUpdateListeners {
+		err := l.AfterAppUpdate(ctx, app)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *Server) FireBeforeAppDelete(ctx context.Context, appName string) error {
+	for _, l := range s.AppDeleteListeners {
+		err := l.BeforeAppDelete(ctx, appName)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *Server) FireAfterAppDelete(ctx context.Context, appName string) error {
+	for _, l := range s.AppDeleteListeners {
+		err := l.AfterAppDelete(ctx, appName)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}