Added arn to the main repository

arn/Joinable.go

@@ -0,0 +1,53 @@
+package arn
+
+import (
+	"github.com/aerogo/aero"
+	"github.com/aerogo/api"
+)
+
+// Joinable is an object where users can join and leave.
+type Joinable interface {
+	Join(*User) error
+	Leave(*User) error
+	Save()
+}
+
+// JoinAction returns an API action that lets the user join the object.
+func JoinAction() *api.Action {
+	return &api.Action{
+		Name:  "join",
+		Route: "/join",
+		Run: func(obj interface{}, ctx aero.Context) error {
+			user := GetUserFromContext(ctx)
+			joinable := obj.(Joinable)
+			err := joinable.Join(user)
+
+			if err != nil {
+				return err
+			}
+
+			joinable.Save()
+			return nil
+		},
+	}
+}
+
+// LeaveAction returns an API action that unpublishes the object.
+func LeaveAction() *api.Action {
+	return &api.Action{
+		Name:  "leave",
+		Route: "/leave",
+		Run: func(obj interface{}, ctx aero.Context) error {
+			user := GetUserFromContext(ctx)
+			joinable := obj.(Joinable)
+			err := joinable.Leave(user)
+
+			if err != nil {
+				return err
+			}
+
+			joinable.Save()
+			return nil
+		},
+	}
+}