1 files changed, 85 insertions, 0 deletions
diff --git a/catalog-ui/src/app/services/event-listener-service.ts b/catalog-ui/src/app/services/event-listener-service.ts
new file mode 100644
index 0000000000..51aa857e51
--- /dev/null
+++ b/catalog-ui/src/app/services/event-listener-service.ts
@@ -0,0 +1,85 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * SDC
+ * ================================================================================
+ * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+/**
+ * Created by obarda on 7/4/2016.
+ */
+'use strict';
+import {Dictionary} from "../utils/dictionary/dictionary";
+
+interface IEventListenerService {
+
+}
+
+interface ICallbackData {
+    callback:Function;
+    args:any[];
+}
+
+export class EventListenerService implements IEventListenerService {
+
+    public observerCallbacks:Dictionary<string, ICallbackData[]> = new Dictionary<string, Array<ICallbackData>>();
+
+    //register an observer + callback
+    public registerObserverCallback = (eventName:string, callback:Function, ...args) => {
+        let callbackData = {
+            callback: callback,
+            args: args
+        }
+
+        if (this.observerCallbacks.containsKey(eventName)) {
+            let callbacks = this.observerCallbacks.getValue(eventName);
+
+            // Only insert the callback if the callback is different from existing callbacks.
+            for (let i = 0; i < callbacks.length; i++) {
+                if (callbacks[i].toString() === callback.toString()) {
+                    return; // Do not add this callback.
+                }
+            }
+
+            callbacks.push(callbackData);
+            this.observerCallbacks.setValue(eventName, callbacks);
+        } else {
+            this.observerCallbacks.setValue(eventName, [callbackData]);
+        }
+    };
+
+    //unregister an observer
+    public unRegisterObserver = (eventName:string, callbackFunc?:Function) => {
+        if (this.observerCallbacks.containsKey(eventName)) {
+
+            let callbacks: ICallbackData[]  =  this.observerCallbacks.getValue(eventName);
+            if(callbacks.length === 1) {
+                this.observerCallbacks.remove(eventName);
+            } else {
+                let filterCallbacks = _.filter(callbacks, (callBackObj) => {
+                    return callBackObj.callback != callbackFunc;
+                });
+                this.observerCallbacks.setValue(eventName, filterCallbacks);
+            }
+
+        }
+    };
+
+    public notifyObservers = function (eventName:string, ...args) {
+        _.forEach(this.observerCallbacks.getValue(eventName), (callbackData:ICallbackData) => {
+            callbackData.callback(...args);
+        });
+    };
+}