Initial commit

src/app/_services/alert.service.ts

@@ -0,0 +1,58 @@
+import { Injectable } from '@angular/core';
+import { Router, NavigationStart } from '@angular/router';
+import { Observable } from 'rxjs';
+import { Subject } from 'rxjs/Subject';
+ 
+import { Alert } from '../_classes/alert';
+import { AlertType } from '../_classes/alertType';
+ 
+@Injectable()
+export class AlertService {
+    private subject = new Subject<Alert>();
+    private keepAfterRouteChange = false;
+ 
+    constructor(private router: Router) {
+        // clear alert messages on route change unless 'keepAfterRouteChange' flag is true
+        router.events.subscribe(event => {
+            if (event instanceof NavigationStart) {
+                if (this.keepAfterRouteChange) {
+                    // only keep for a single route change
+                    this.keepAfterRouteChange = false;
+                } else {
+                    // clear alert messages
+                    this.clear();
+                }
+            }
+        });
+    }
+ 
+    getAlert(): Observable<any> {
+        return this.subject.asObservable();
+    }
+ 
+    success(message: string, keepAfterRouteChange = false) {
+        this.alert(AlertType.Success, message, keepAfterRouteChange);
+    }
+ 
+    error(message: string, keepAfterRouteChange = false) {
+        this.alert(AlertType.Error, message, keepAfterRouteChange);
+    }
+ 
+    info(message: string, keepAfterRouteChange = false) {
+        this.alert(AlertType.Info, message, keepAfterRouteChange);
+    }
+ 
+    warn(message: string, keepAfterRouteChange = false) {
+        this.alert(AlertType.Warning, message, keepAfterRouteChange);
+    }
+ 
+    alert(type: AlertType, message: string, keepAfterRouteChange = false) {
+        this.keepAfterRouteChange = keepAfterRouteChange;
+        this.subject.next(<Alert>{ type: type, message: message });
+    }
+ 
+    clear() {
+        // clear alerts
+        this.subject.next();
+    }
+}