first implementation of Cairngorm

src/model/AppModelLocator.hx

@@ -0,0 +1,76 @@
+package model;
+
+import vo.Rider;
+import feathers.data.ArrayCollection;
+import openfl.errors.Error;
+import openfl.events.Event;
+import com.adobe.cairngorm.model.IModelLocator;
+import openfl.events.EventDispatcher;
+
+class AppModelLocator extends EventDispatcher implements IModelLocator {
+
+    // events constants
+    public static final VIEWING_CHANGE = "viewingChange";
+    public static final RIDERS_LIST_DP_CHANGE = "ridersListDPChange";
+
+
+    // this instance stores a static reference to itself
+	private static var model:AppModelLocator;
+
+    // available values for the main viewstack defined as constants to help uncover errors at compile time instead of run time
+	public static final ADMIN_LOGIN = 0;
+	public static final RIDERS_LIST = 1;
+	public static final RIDER_DETAIL = 2;
+
+    // viewstack starts out on the admin login screen
+	public var viewing(default, set):Int = ADMIN_LOGIN;
+
+    private function set_viewing(value:Int):Int {
+		viewing = value;
+		dispatchEvent(new Event(VIEWING_CHANGE));
+		return viewing;
+	}
+
+    // rider object contains uid/passwd
+	// its value gets set at login and cleared at logout but nothing binds to it or uses it
+	// retained since it was used in the original Adobe CafeTownsend example app
+	/*public var user(default, set):User;
+
+	private function set_user(value:User):User {
+		user = value;
+		dispatchEvent(new Event(USER_CHANGE));
+		return user;
+	}*/
+
+    // contains the main riders list which is populated on startup
+	// mx:application's creationComplete event is mutated into a cairngorm event
+	// that calls the httpservice for the data
+	public var ridersListDP(default, set):ArrayCollection<Rider>;
+
+    private function set_ridersListDP(value:ArrayCollection<Rider>):ArrayCollection<Rider> {
+		ridersListDP = value;
+		dispatchEvent(new Event(RIDERS_LIST_DP_CHANGE));
+		return ridersListDP;
+	}
+
+    // variable to store error messages from the httpservice 
+    // nothinng currently binds to it, but an Alert or the login box could to show startup errors
+	public var errorStatus:String;
+
+
+    // singleton: constructor only allows one model locator
+	public function new() {
+		super();
+		if (AppModelLocator.model != null) {
+			throw new Error("Only one ModelLocator instance should be instantiated");
+		}
+	}
+
+	// singleton: always returns the one existing static instance to itself
+	public static function getInstance():AppModelLocator {
+		if (model == null)
+			model = new AppModelLocator();
+		return model;
+	}
+
+}