upload image from ipad app to node js server using multiparty

Question

I am very new to javascript and node js. I am working on uploading image from my iPad app to rest api of node js(express js) using multiparty module.

Here is my image upload code in objective c.

NSData *imgData = UIImageJPEGRepresentation(img.image, 0.2);
NSString *urlString = @"http://localhost:3000/api/uploadimage";
NSString *str = @"displayImage";

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
[request setHTTPShouldHandleCookies:NO];
[request setTimeoutInterval:30];
[request setURL:[NSURL URLWithString:urlString]];

[request setHTTPMethod:@"POST"];

NSString *boundary = [NSString stringWithFormat:@"---------------------------14737809831464368775746641449"];

NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
[request setValue:contentType forHTTPHeaderField: @"Content-Type"];

NSMutableData *body = [NSMutableData data];

[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"currentEventID\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"52344457901000006" dataUsingEncoding:NSUTF8StringEncoding]];

if (imgData) {
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    // [body appendData:[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"displayImage\"; filename=\"myimage.jpg\"\r\n"]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"myimage.jpg\"\r\n", str] dataUsingEncoding:NSUTF8StringEncoding]];

    [body appendData:[@"Content-Type: image/jpeg\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:imgData];
    [body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
}


[body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];

[request setURL:[NSURL URLWithString:urlString]];  
NSLog(@"HttpBody = %@",request.HTTPBody);
connectionSave =  [[NSURLConnection alloc] initWithRequest:request delegate:self];

Request body data is printed on console.

For getting image on server side I am referring this example. [https://github.com/strongloop/express/blob/master/examples/multipart/index.js][1]

In this example, they are creating var form = new multiparty.Form(); in post method. But I am sending image from application not from browser so I don’t have any form in which input types are defined. How can I write this REST API to get the image and other string parameters?

var express = require('express');
var http = require('http');
var util = require('util')
var multiparty = require('multiparty');

var app = express();
var bodyParser = require('body-parser');

app.use(bodyParser.urlencoded({
    extended: true
}));

app.use(bodyParser.json());

app.use(bodyParser.urlencoded({limit:'10mb', extended: true}));
app.use(bodyParser.json({limit:'10mb'})); 

app.post('/api/uploadimage', function(req, res, next){
    var form = new multiparty.Form();

    console.log(req.body);
});

Also I am getting req.body empty. Thanks in Advance!! :)

Answer 1

your objective code is looking perfect. You need to use connect-multiparty module. Here is the sample code to save the file.

    app.post('/api/uploadimage', multipartMiddleware, function(req, res) {
         console.log(req.body, req.files); // check console 

    fs.readFile(req.files.urForm-data_name.path, function (err, data) {
            //here get the image name and other data parameters which you are sending like image name etc.
           fs.writeFile(newPath, data, function (err) {
          });
   //dont forgot the delete the temp files.
        });
     });

Answer 2

I don't know iOS code is right or wrong, but in nodejs case, you should use multiparty as a middleware,you can use connect-multiparty

var multipart = require('connect-multiparty');
var multipartMiddleware = multipart();
app.use(require('body-parser').urlencoded({
    extended: true
}))
app.post("/api/upload", multipartMiddleware, function(req, res){
    files = req.files;
    // Do ....
});