added loading page on login api call

src/app/auth/login/login.page.ts

 import { Component, OnInit } from '@angular/core';
-import { Router } from '@angular/router';
+import { Router, LoadChildrenCallback } from '@angular/router';
 
 import { Observable } from 'rxjs';
 import { HttpClient } from '@angular/common/http';
 
 import { RestService } from '../../rest.service';
 import { UserService } from 'src/app/services/user.service';
+import { LocationService } from 'src/app/services/location.service';
+import { LoadingService } from 'src/app/services/loading.service';
 
 @Component({
   selector: 'app-login',
@@ -15,12 +17,15 @@ import { UserService } from 'src/app/services/user.service';
 export class LoginPage implements OnInit {
   username = "";
   password = "";
-  //username = "";
-  //password = "";
   correctCredentials = false;
   loginApi: Observable<any>;
 
-  constructor(private router: Router, public httpClient: HttpClient, public restService: RestService,public userService: UserService) {
+  constructor(private router: Router,
+    public httpClient: HttpClient,
+    public restService: RestService,
+    public userService: UserService,
+    public locationService: LocationService,
+    public loadingService: LoadingService) {
 
   }
 
@@ -37,6 +42,7 @@ export class LoginPage implements OnInit {
       "email": this.username,
       "password": this.password
     });
+    this.loadingService.showLoader();
     this.loginApi
       .subscribe((data) => {
         //console.log('my data: ', data);
@@ -44,9 +50,11 @@ export class LoginPage implements OnInit {
         this.restService.isLoginPage = false;
         this.userService.setUsername(this.username);
         this.router.navigateByUrl('/home');
+        this.loadingService.hideLoader();
       }, (error) => {
         console.log(JSON.stringify(error));
         this.correctCredentials = true;
+        this.loadingService.hideLoader();
       });
   }
   register() {