Change filename when using express/multer

Question

I'm having trouble uploading a pdf, when I upload it (I'm using ng-file-upload) the file json that reachs express.js is:

{ fieldname: 'file',
  originalname: 'db.pdf',
  encoding: '7bit',
  mimetype: 'application/pdf',
  destination: './client/public/docs/transactions/',
  filename: '8a3fe7cb7369d9cffa8e17b162ec3d6b',
  path: 'client\\public\\docs\\transactions\\8a3fe7cb7369d9cffa8e17b162ec3d6b',
  size: 9179145 }

I'd like to change the name to a property that I send from angular to express, here's all the setup:

html element:

<div ngf-select="vm.uploadPdf($file, $errFiles)"
     ngf-pattern="'.pdf'"
     accept="application/pdf" ngf-max-size="20MB">Select ...
</div>

angular func uploadPdf (ctrl as vm):

function uploadPdf( file, errFiles ) {
    vm.pdf = file;
    vm.errorFile = errFiles && errFiles[ 0 ];

    if ( vm.pdf ) {
        Upload
            .upload( {
                url: '/upload',
                data: {
                    file: vm.pdf,
                    new_file_name: vm.new_name//this is the filename I want
                }
            } )
            .then(
                function ( response ) {
                    $timeout( function () {
                        vm.pdf.result = response.data;
                    } );
                }, function ( response ) {
                    if ( response.status > 0 ) {
                        vm.errorQuedanPdfUpload = response.status + ': ' + response.data;
                        console.log( vm.errorQuedanPdfUpload );
                    }
                }
            );
    }
}

express:

var express = require( 'express' ),
    router  = express.Router(),
    util    = require( 'util' ),
    multer  = require( 'multer' );

var storage = multer.diskStorage(
    {
        destination: './uploads/',
        filename: function ( req, file, cb ) {
            //req.body is empty...
            //How could I get the new_file_name property sent from client here?
            cb( null, file.originalname );
        }
    }
);

var upload = multer( { storage: storage } );

router.route( '/upload' )
    .post( upload.single( 'file' ), post );

function post( request, response ) {

    response.json( { message: 'Files Uploaded!' } );

}

Answer 1

var express = require( 'express' ),
    router  = express.Router(),
    util    = require( 'util' ),
    multer  = require( 'multer' );

var storage = multer.diskStorage(
    {
        destination: './uploads/',
        filename: function ( req, file, cb ) {
            //req.body is empty...
            //How could I get the new_file_name property sent from client here?
            cb( null, file.originalname+ '-' + Date.now()+".pdf");
        }
    }
);

var upload = multer( { storage: storage } );

router.route( '/upload' )
    .post( upload.single( 'file' ), post );

function post( request, response ) {

    response.json( { message: 'Files Uploaded!' } );

}