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How to parse an object sent from react frontend in express.js?

So in my react front-end, I am using the 'react-drop-to-upload' module to allow the user to drag a file and upload. I followed the example on the npm module page and created a handler called handleDrop. The code looks like:
handleDrop(files) {
var data = new FormData();
alert((files[0]) instanceof File);
files.forEach((file, index) => {
data.append('file' + index, file);
});
fetch('/file_upload', {
method: 'POST',
body: data
});
}
At my express backend, I have the following code:
app.post('/file_upload', function(req , res){
var body = '';
req.on('data', function (data) {
body += data;
});
var post = "";
req.on('end', function () {
//post = qs.parse(body);
console.log(body);
// this won't create a buffer for me
//var fileBuffer = new Buffer(body);
//console.log(fileBuffer.toString('ascii'));
//pdfText(body, function(err, chunks) {
//console.log(chunks);
//});
});
//console.log(typeof post);
});
If I drop a txt file and do a console log on the body, it would give me:
------WebKitFormBoundaryqlp9eomS0BxhFJkQ
Content-Disposition: form-data; name="file0"; filename="lec16.txt"
Content-Type: text/plain
The content of my data!
------WebKitFormBoundaryqlp9eomS0BxhFJkQ--
I am trying to use the pdfText module which takes in a buffer or a pathname to the pdf file, extract text from it into an array of text 'chunks' . I want to convert the body object into a buffer using var fileBuffer = new Buffer(body); but that won't work. Can someone help me with this? Thanks!

You need a parser for multi-part data. You can look into multer regarding that.
Example code for you,
app.post('/file_upload', function(req , res){
var storage = multer.diskStorage({
destination: tmpUploadsPath
});
var upload = multer({
storage: storage
}).any();
upload(req, res, function(err) {
if (err) {
console.log(err);
return res.end('Error');
} else {
console.log(req.body);
req.files.forEach(function(item) {
// console.log(item);
// do something with the item,
const data = fs.readFileSync(item.path);
console.log(data);
});
res.end('File uploaded');
}
});
});
To understand the example code in depth, head here. Remember, you will get the file data as a buffer and not as actual data.

How to configure API endpoint to receive file from ember-uploader component

I'm trying to figure out how to use ember-uploader, I have the following component (like the one in the README)
export default EmberUploader.FileField.extend({
filesDidChange: function(files) {
const uploader = EmberUploader.Uploader.create({
url: (ENV.APP.API_HOST || '') + '/api/v1/images/',
});
console.log(uploader);
if (!Ember.isEmpty(files)) {
var photo = files[0];
console.log(photo);
uploader.upload(photo)
.then(data => {
// Handle success
console.log("Success uploading file");
console.log(data);
}, error => {
// Handle failure
console.log("ERROR uploading file");
console.log(error);
});
}
}
});
The express API endpoint is listening for a POST request.
var saveImage = (req, res, next) => {
let body = req.body;
res.json({
data: body
});
};
But the body is empty after the request is done. I really don't know how to implement the API endpoint in order to get the file, I tried to see the req object and it doesn't contains the file.
Debugging it, After select a file using the component I get the following info in the console.
Seems that the API endpoint works because I get the following output:
POST /api/v1/images/ 200 27.284 ms - 11
But I can't get the file.

SOLUTION
In Express 4, req.files is no longer available on the req object by
default. To access uploaded files on the req.files object, use a
multipart-handling middleware like busboy, multer, formidable,
multiparty, connect-multiparty, or pez.
Following this blog, the code below was added to the API and the ember-uploader code posted in the question worked as expected.
import formidable from 'formidable';
var saveImage = (req, res, next) => {
var form = new formidable.IncomingForm();
form.parse(req);
form.on('fileBegin', function (name, file){
file.path = __dirname + '/tmp/' + file.name;
});
form.on('file', function (name, file){
res.json({
data: file.name
});
});
};

How do I write an image to buffer using native Node JS HTTP library?

I am really new to JavaScript and Node JS. I have various image URLs that I want to buffer. I have tried the request npm module but want a lower level library for what I want to achieve.
For example:
http://assets.loeildelaphotographie.com/uploads/article_photo/image/128456/_Santu_Mofokeng_-_TOWNSHIPS_Shebeen_Soweto_1987.jpg
I see lots of examples that suggest using the request module or examples that save files to disk. However, I cannot find an HTTP GET request example that simply buffers the image so I can pass to another function. It needs to have an "end" event so I upload the buffered image data with confidence in another step. Is there a sample pattern or "how to" on this someone could provide? Thanks!

This is the native way:
var http=require('http'), imageBuffer;
http.get(
'http://www.kame.net/img/kame-anime-small.gif',
function(res) {
var body=new Buffer(0);
if (res.statusCode!==200) {
return console.error('HTTP '+res.statusCode);
}
res.on('data', function(chunk) {
body=Buffer.concat([body, chunk]);
});
res.on('end', function() {
imageBuffer=body;
});
res.on('error', function(err) {
console.error(err);
});
}
);
// Small webserver serving the image at http://127.0.0.1:4567
http.createServer(function(req, res) {
res.write(imageBuffer || 'Please reload page');
res.end();
}).listen(4567, '127.0.0.1');
and using request (encoding:null for binary response):
var request=require('request'), imageBuffer;
request({
uri: 'http://www.kame.net/img/kame-anime-small.gif',
encoding: null
}, function(err, res, body) {
if (err) {
return console.error(err);
} else if (res.statusCode!==200) {
return console.error('HTTP '+res.statusCode);
}
imageBuffer=body;
});
// Small webserver serving the image at http://127.0.0.1:4567
require('http').createServer(function(req, res) {
res.write(imageBuffer || 'Please reload page');
res.end();
}).listen(4567, '127.0.0.1');

Here's a simple example using the built-in streaming that the http response has:
var http = require('http');
var fs = require('fs');
var file = fs.createWriteStream("test.png");
var request = http.get("some URL to an image", function(response) {
response.pipe(file);
});
I ran this myself and successfully downloaded an image from an external web site and saved it to a file and then loaded the file into the browser to see the same image.

Cannot save a remote image with node.js and request

I want to save an image with node.js and the request library. So far I have this simple code:
var request = require('request');
var fs = require('fs');
request('http://upload.wikimedia.org/wikipedia/commons/8/8c/JPEG_example_JPG_RIP_025.jpg', function(error, response, body)
{
// further logic that decides
// whether or not the image will be saved
fs.writeFile('downloaded.jpg', body, function(){});
});
But it doesn't work. The image always arrives corrupt. I assume it's an encoding error but I cannot figure out how to fix this.

var request = require('request'),
fs = require('fs'),
url = 'http://upload.wikimedia.org/wikipedia/commons/8/8c/JPEG_example_JPG_RIP_025.jpg';
request(url, {encoding: 'binary'}, function(error, response, body) {
fs.writeFile('downloaded.jpg', body, 'binary', function (err) {});
});

var fs = require('fs'),
request = require('request'),
url='http://upload.wikimedia.org/wikipedia/commons/8/8c/JPEG_example_JPG_RIP_025.jpg';
request(url).pipe(fs.createWriteStream('downloaded.jpg'));

Here's how I did it using stream and pipe, (I was using express but you may not need that)
var express = require('express');
var app = express();
var filesystem = require('fs');
var https = require('https');
var download = function(url, dest, cb) {
var file = filesystem.createWriteStream(dest);
var request = https.get(url, function(httpResponse) {
httpResponse.pipe(file);
file.on('finish', function() {
console.log("piping to file finished")
file.close(cb); // close() is async, call cb after close completes.
});
}).on('error', function(err) { // Handle errors
filesystem.unlink(dest); // Delete the file async. (But we don't check the result)
if (cb) cb(err.message);
});
};
app.get('/image', (req, res) => {
download('https://lastfm-img2.akamaized.net/i/u/64s/15cc734fb0e045e3baac02674d2092d6.png',
'porcupine.png',
() => {console.log("downloaded to porcupine.png")})
})
When I run using node server.js and hit the url localhost:3000/image, it will download and save the file to porcupine.png in the base directory.

How to serve (uploaded) images using Meteor

I have this Meteor application in which it is possible to upload images. The uploading parts seem to work. I store the images in .uploads. Now I would like to make these images accessable by the following URL
http://localhost:3000/uploads
After a bit of googling I was able to create the following server side code:
var fs = Meteor.require('fs');
if (Meteor.isServer) {
WebApp.connectHandlers.stack.splice(0, 0, {
route: '/uploads',
handle: function (req, res, next) {
var path = process.env.PWD + '/.' + req.originalUrl.substr(1);
fs.readFile(path, {encoding: 'binary'}, function (err,data) {
if (err) {
throw err;
}
res.writeHead(200, {
'Content-Type': 'image/png'
});
//res.setEncoding("binary"); // this method does not exist
res.write(data);
res.end();
});
}
});
}
This code works, the path constructed is correct and in the browser I receive the 200 code, except it cannot display the image. Something is wrong with the data the browser receives. I checked the image on disk which is fine. So the code above must do something wrong with the data. Any suggestions what that might be?

Here is the code I found after googling (and works for me) a few days ago when I wanted to do what you need to do
files are in .screenshots directory mapped to :
http://localhost:3000/screenshots
code :
//directly serve screenshot files from /.screenshots dir
var fs = Npm.require('fs');
WebApp.connectHandlers.use(function(req, res, next) {
var re = /^\/screenshots\/(.*)$/.exec(req.url);
if (re !== null) { // Only handle URLs that start with /screenshots/*
var filePath = process.env.PWD + '/.screenshots/' + re[1];
var data = fs.readFileSync(filePath, data);
res.writeHead(200, {
'Content-Type': 'image'
});
res.write(data);
res.end();
} else { // Other urls will have default behaviors
next();
}
});