refactor/#386 ObservablePattern 다중 구독 구현

KkuMulKum/Resource/ObservablePattern/ObservablePattern.swift

@@ -10,42 +10,61 @@ import Foundation
 class ObservablePattern<T> {
     var value: T {
         didSet {
-            listener?(value)
+            notifyListeners(value)
         }
     }
 
-    private var listener: ((T) -> Void)?
+    typealias Listener = (T) -> Void
+
+    private var listeners: [Listener] = []
 
     init(_ value: T) {
         self.value = value
     }
 
+    private func notifyListeners(_ value: T) {
+        for listener in listeners {
+            listener(value)
+        }
+    }
+
     func bind(_ listener: @escaping (T) -> Void) {
-        self.listener = listener
+        listeners.append(listener)
+
+        listener(value)
     }
 
     func bind<Object: AnyObject>(with object: Object, _ listener: @escaping (Object, T) -> Void) {
-        self.listener = { [weak object] value in
+        listeners.append { [weak object] value in
             guard let object else { return }
             listener(object, value)
         }
+
+        listener(object, value)
     }
 
     func bindOnMain(_ listener: @escaping (T) -> Void) {
-        self.listener = { value in
+        listeners.append { value in
             DispatchQueue.main.async {
                 listener(value)
             }
         }
+
+        DispatchQueue.main.async {
+            listener(self.value)
+        }
     }
 
     func bindOnMain<Object: AnyObject>(with object: Object, _ listener: @escaping (Object, T) -> Void) {
-        self.listener = { [weak object] value in
+        listeners.append { [weak object] value in
             guard let object else { return }
             DispatchQueue.main.async {
                 listener(object, value)
             }
         }
+
+        DispatchQueue.main.async {
+            listener(object, self.value)
+        }
     }
 }
-