Unable to post file in angular2 with node

please see this code this one is working for me service:-

import { Component } from 'angular2/core';
import { Injectable } from 'angular2/core';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/share';

@Injectable()
export class FileUploadService {
/**
 * @param Observable<number>
 */
private progress$: Observable<number>;

/**
 * @type {number}
 */
private progress: number = 0;

private progressObserver: any;

constructor () {
    this.progress$ = new Observable(observer => {
        this.progressObserver = observer
    });
}

/**
 * @returns {Observable<number>}
 */
public getObserver (): Observable<number> {
    return this.progress$;
}

/**
 * Upload files through XMLHttpRequest
 *
 * @param url
 * @param files
 * @returns {Promise<T>}
 */
public upload (url: string, files: File[]): Promise<any> {
    return new Promise((resolve, reject) => {
        let formData: FormData = new FormData(),
            xhr: XMLHttpRequest = new XMLHttpRequest();

        for (let i = 0; i < files.length; i++) {
            formData.append("uploads", files[i], files[i].name);
        }

        xhr.onreadystatechange = () => {
            if (xhr.readyState === 4) {
                if (xhr.status === 200) {
                    resolve(JSON.parse(xhr.response));
                } else {
                    reject(xhr.response);
                }
            }
        };

        FileUploadService.setUploadUpdateInterval(500);

        xhr.upload.onprogress = (event) => {
            this.progress = Math.round(event.loaded / event.total * 100);

            this.progressObserver.next(this.progress);
        };

        xhr.open('POST', url, true);
        xhr.send(formData);
    });
}

/**
 * Set interval for frequency with which Observable inside Promise will share data with subscribers.
 *
 * @param interval
 */
private static setUploadUpdateInterval (interval: number): void {
    setInterval(() => {}, interval);
}
}

component file:-

import {Component, View, Inject} from 'angular2/core';


import {FileUploadService} from '../../services/fileUploadService';
@Component({
    selector: 'home',
    providers: [FileUploadService]
})
@View({
    templateUrl: '/scripts/src/components/home/home.html',
})
export class HomeComponent {
    psdTemplates: any;
    status: number;
    constructor( @Inject(FileUploadService) private fileUploadService: FileUploadService) {
        this.psdTemplates = new Array<File>();
    }
    public psdTemplateSelectionHandler(fileInput: any) {
        console.log(fileInput);
        let FileList: FileList = fileInput.target.files;
        this.psdTemplates.length = 0;
        for (let i = 0, length = FileList.length; i < length; i++) {
            this.psdTemplates.push(FileList.item(i));
        }
        console.log(this.psdTemplates);
        // this.progressBarVisibility = true;
    }
    public psdTemplateUploadHandler() {
        let result: any;

        if (!this.psdTemplates.length) {
            return;
        }


        this.fileUploadService.getObserver()
            .subscribe(progress => {
                console.log(progress);
                this.status = progress;
            });

        try {
            result = this.fileUploadService.upload('/upload', this.psdTemplates).then((res) => {
                console.log(res);
            }, (err) => { console.log(err); });
        } catch (error) {
            document.write(error)
        }
        console.log(result);
        if (!result['images']) {
            return;
        }

        // this.saveUploadedTemplatesData(result['images']);
    }
}

html :-

 <h3>File Upload</h3>

<div>
    Select file:
    <input type="file" (change)="psdTemplateSelectionHandler($event)" name="userPhoto">
</div>
<input type="button" value="click" (click)="psdTemplateUploadHandler()" /> {{status}}

Server side :-

var storage = multer.diskStorage({
    destination: function(req, file, callback) {
        console.log(file);
        callback(null, './public/images');
    },
    filename: function(req, file, callback) {
        console.log(file);
        callback(null, file.fieldname + '-' + Date.now() + '.' + file.originalname.split('.')[1]);
    }
});
var upload = multer({ storage: storage }).single('uploads');
app.post("/upload", function(req, res) {
    upload(req, res, function(err) {
        if (err) {
            return res.send({ status: 'Error uploading file' });
        }
        res.send({ status: "File is uploaded" });
    });
});