constructor(private nav: NavController, 
              public navParams: NavParams, 
              public config: Config, 
              public guestService: GuestService) {
    this.guest = navParams.get('guest');
    this.group = navParams.get('group');
    this.isTheLastGuestToRate = navParams.get('flag');
    this.allFilled = false;
    this.score = [];
    this.response = [];
    this.isMentor = this.config.get('MENTOR');
    this.isHomestay = this.config.get('HOMESTAY');
    this.error = false;

    if(this.guest) {
      if(this.guest.score) {
        this.getGuestDiyData();
      } else if (this.group.diy_model) {
        this.getGuestDiyModel();
      } else {
        this.error = true;
        console.error('Parameter error');
      }
    }
  }

	constructor(private app: App, component: ImageViewerComponent, opts: ImageViewerOptions = {}, config: Config) {
		super(component, opts);

		config.setTransition('image-viewer-enter', ImageViewerEnter);
		config.setTransition('image-viewer-leave', ImageViewerLeave);

		this.didLeave.subscribe(() => opts.onCloseCallback && opts.onCloseCallback());

		this.willEnter.subscribe(() => this.handleHighResImageLoad(opts.fullResImage));
	}

 constructor(public nav: NavController, 
             public navParams: NavParams, 
             public config: Config, 
             public uploadService: UploadService) {
   this.initSignature(this);
   this.group = navParams.get('group'); 
   this.guest = navParams.get('guest'); 
   this.isHomestay = false;
   this.isMentor = false;
   this.isHandling = false;
   if(this.config.get('HOMESTAY')) {
     this.isHomestay = true;
   }
   if(this.config.get('MENTOR')) {
     this.isMentor = true;
   }
 }

  btnClick(button: any, dismissDelay?: number) {
    if (!this.isEnabled()) {
      return;
    }

    // keep the time of the most recent button click
    this.lastClick = Date.now();

    let shouldDismiss = true;

    if (button.handler) {
      // a handler has been provided, execute it
      // pass the handler the values from the inputs
      if (button.handler(this.getValues()) === false) {
        // if the return value of the handler is false then do not dismiss
        shouldDismiss = false;
      }
    }

    if (shouldDismiss) {
      setTimeout(() => {
        this.dismiss(button.role);
      }, dismissDelay || this._config.get('pageTransitionDelay'));
    }
  }

  openContact(speaker: SpeakerModel) {
    let mode = this.config.get('mode');

    let actionSheet = this.actionSheetCtrl.create({
      title: 'Contact with ' + speaker.name,
      buttons: [
        {
          text: `Email ( ${speaker.email} )`,
          icon: mode !== 'ios' ? 'mail' : null,
          handler: () => {
            window.open('mailto:' + speaker.email);
          }
        },
        {
          text: `Call ( ${speaker.phone} )`,
          icon: mode !== 'ios' ? 'call' : null,
          handler: () => {
            window.open('tel:' + speaker.phone);
          }
        }
      ]
    });

    actionSheet.present();
  }

 .then(data => {
   this.response = data;
   if(this.response.hash){
     this.config.set('HASH', this.response.hash);
     this.local.set('HASH', this.response.hash);
     this.local.set('AUTHORIZED', true);
     this.nav.setRoot(LeaderPage);
   } else {
     this.codeIncorrect('Error.', this.response.error.message);    
   }
 });

  editApp(app) {

    let body = JSON.stringify(app);
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

   return this.http.put(this.config.get('apiUrl') + 'apps/' + app._id, body, options)
       .toPromise()
       .then(res => {
         return true;
       })
       .catch(err=>console.log(err));
  }

 .then(data => {
   this.response = data;
   if(this.response.hash) {
     this.config.set('HASH', this.response.hash);
     this.local.set('HASH', this.response.hash);
     this.local.set('AUTHORIZED', true);
     if(this.response.is_homestay) {
       this.config.set('HOMESTAY', true);
       this.config.set('MENTOR', false);
       this.local.set('HOMESTAY', true);
       this.local.set('MENTOR', false);
       this.nav.setRoot(HomestayPage);
     } else {
       this.config.set('HOMESTAY', false);
       this.config.set('MENTOR', true);
       this.local.set('HOMESTAY', false);
       this.local.set('MENTOR', true);
       this.nav.setRoot(MentorPage);
     }
   } else if(this.response.error){
     this.codeIncorrect('Error.', this.response.error.message);    
   }
 });

 initializePage() {
   if(this.config.get('HASH')) {
     this.homeService.load(0)
     .then(data => {
       this.group = data;
       if(!this.group.pics){
         this.group.pics = [];
       }
       if(this.group.error) {
         this.group = [];
         this.presentAlert(this.group.error.message);
       }
     });
   }
 }

 .then(data => {
   this.response = data;
   if(this.response.hash){
     this.firstName = this.response.first_name; 
     this.lastName = this.response.last_name; 
     this.loginCodeCorrect = true;
     this.config.set('HASH', this.response.hash);
     this.local.set('HASH', this.response.hash);
   } else {
     this.firstName = ""; 
     this.lastName = ""; 
     this.codeIncorrect('Password error', 'Please try again later');    
     this.loginCodeCorrect = false;
   }
   this.isHandling = false;
   loading.dismiss();
 });