javascript - How do i pass image to a function Ionic 2 -

i image service class via code

 this.cameraservice.getimage(this.width, this.height, this.quality).subscribe(data => this.image = data, error => 

i want pass code 1 of getvision() function able use google api.may know how do it? tried declaring string variable , try put above code inside variable not work.below codes

camera.ts class      export class camerapage {      width: number;   height: number;   cropper: cropper;*/    image:string;   width:number = 500;   height:number = 500;   quality:number = 90;   picture:string;    labels: array<any> = [];   //translation   scanning: array<any> = [];   choselang: boolean = false;   loading: boolean = false;     constructor(public navctrl: navcontroller, public navparams: navparams,public testservice: testservice,public cameraservice: cameraservice,public toastctrl: toastcontroller) {    }     addphoto(){ //take picture & return image ***     this.cameraservice.getimage(this.width, this.height, this.quality).subscribe(data => this.image = data, error =>     {        this.getvision(this.image);        // toast errot , return default_photo constants       this.toast(error);       });      }    toast(message: string) {     let toast = this.toastctrl.create({       message: message,       duration: 2500,       showclosebutton: false     });     toast.present();   }     getvision(image64:string) {      this.testservice.getvisionlabels(image64:string)     .subscribe((sub) => {        this.labels = sub.responses[0].textannotations;         this.gettext();      });  }    gettext() {    this.labels.foreach((label) => {     let translation = {search: label.description, result: ''};      console.log(label.description);    }); }  } 

camera service class

  export class cameraservice {   public base64image: string;         constructor(public platform: platform, public alertctrl: alertcontroller, public modalctrl: modalcontroller, private http: http) {    }      getimage(width: number, height: number, quality: number) {     return observable.create(observer => {       //set default options taking image camera       let imageoptions: = {         quality: quality,         destinationtype: camera.destinationtype.data_url,         sourcetype: camera.picturesourcetype.camera,         encodingtype: camera.encodingtype.jpeg,         correctorientation: 1,         savetophotoalbum: false,         mediatype: camera.mediatype.picture,         cameradirection: 1       };        let selectalert = this.alertctrl.create({         title: 'let\'s add picture!',         message: "select how add picture",         enablebackdropdismiss: false,         buttons: [{           text: 'albums',           handler: data => {             //change sourcetype photolibrary             imageoptions.sourcetype = camera.picturesourcetype.photolibrary;             selectalert.dismiss();           }         }, {           text: 'camera',           handler: data => {             selectalert.dismiss();           }         }]       });        selectalert.ondiddismiss(() => {         this.getcameraimage(imageoptions).subscribe(image => {   //image options either album or camera**              let cropmodal = this.modalctrl.create(scannerpage, { "imagebase64": image, "width": 500, "height": 500 });             cropmodal.ondiddismiss((croppedimage: any) => {               if (!croppedimage)                 observer.error("canceled while cropping.")               else {                 observer.next(croppedimage);                 observer.complete();                }             });             cropmodal.present();           }, error => observer.error(error));       });       selectalert.present();     });   }      getcameraimage(options: any) { //get base64 image     return observable.create(observer => {       this.platform.ready().then(() => {         camera.getpicture(options).then((imagedata: any) => {           // imagedata base64 encoded string per options set above           let base64image: string = "data:image/jpeg;base64," + imagedata;           observer.next(base64image);           observer.complete();         }, error => {           observer.error(error);         });       });     });   } } 

you need understand data returned observable service can accessed in .subscribe() callback 1 , not in callback 2. read this more clarification.

this.cameraservice.getimage(this.width,this.height,this.quality)   .subscribe( (data) => {     this.image = data;     this.getvision(this.image);   },(error) => {      // toast errot , return default_photo constants      this.toast(error);   } );