app state

src/app/app.state.ts

@@ -0,0 +1,43 @@
+import {Injectable} from '@angular/core'
+import {Subject}    from 'rxjs/Subject';
+
+@Injectable()
+export class AppState {
+
+  private _data = new Subject<Object>();
+  private _dataStream$ = this._data.asObservable();
+
+  private _subscriptions:Map<string, Array<Function>> = new Map<string, Array<Function>>();
+
+  constructor() {
+    this._dataStream$.subscribe((data) => this._onEvent(data));
+  }
+
+  notifyDataChanged(event, value) {
+
+    let current = this._data[event];
+    if (current != value) {
+      this._data[event] = value;
+
+      this._data.next({
+        event: event,
+        data: this._data[event]
+      });
+    }
+  }
+
+  subscribe(event:string, callback:Function) {
+    var subscribers = this._subscriptions.get(event) || [];
+    subscribers.push(callback);
+
+    this._subscriptions.set(event, subscribers);
+  }
+
+  _onEvent(data:any) {
+    var subscribers = this._subscriptions.get(data['event']) || [];
+
+    subscribers.forEach((callback) => {
+      callback.call(null, data['data']);
+    });
+  }
+}