added shutdown command for the full node to the UI's unload event

Breeze.UI/src/app/app.component.ts

-import { Component, OnInit } from '@angular/core';
+import { Component, OnInit, HostListener } from '@angular/core';
 import { Router } from '@angular/router';
 
 import { ApiService } from './shared/services/api.service';
@@ -26,4 +26,23 @@ export class AppComponent implements OnInit {
     this.loading = false;
     this.router.navigate(['/login']);
   }
+
+  @HostListener('window:unload')
+  unloadHandler() {   
+    this.apiService.shutdownNode().subscribe(
+          response => {},
+          error => {
+            if (error.status === 0) {
+              alert("Error closing application. please close the dotnet process manually.");
+            } else if (error.status >= 400) {
+              if (!error.json().errors[0]) {
+                console.log(error);
+              }
+              else {
+                alert(error.json().errors[0].message);
+              }
+            }
+          }
+        );
+  }
 }

Breeze.UI/src/app/shared/services/api.service.ts

@@ -132,4 +132,10 @@ export class ApiService {
         .post(this.webApiUrl + '/wallet/send-transaction/', JSON.stringify(data), {headers: this.headers})
         .map((response: Response) => response);
     }
+
+    shutdownNode(): Observable<any> {
+      return this.http
+        .post(this.webApiUrl + '/node/shutdown', '')
+        .map((response: Response) => response);
+    }   
 }