refactor Callbacks

lib/obsws/event.rb

@@ -37,19 +37,21 @@ module OBSWS
     module Callbacks
       include Util
 
+      def observers
+        @observers ||= []
+      end
+
       def add_observer(observer)
-        @observers = [] unless defined?(@observers)
         observer = [observer] if !observer.respond_to? :each
-        observer.each { |o| @observers.append(o) }
+        observer.each { |o| observers << o }
       end
 
       def remove_observer(observer)
-        @observers.delete(observer)
+        observers.delete(observer)
       end
 
       def notify_observers(event, data)
-        if defined?(@observers)
+        observers.each do |o|
-          @observers.each do |o|
           if o.respond_to? "on_#{event.to_snake}"
             if data.empty?
               o.send("on_#{event.to_snake}")
@@ -60,7 +62,6 @@ module OBSWS
         end
       end
     end
-    end
 
     class Client
       include Logging