fix drag and drop functions

server.js

@@ -1,7 +1,8 @@
 var PORT = 8080; //Set port for the app
 
-
+fs = require("fs-extra");
 var express = require('express');
+var formidable = require('formidable'); //form upload processing
 var s_whiteboard = require("./s_whiteboard.js");
 
 var app = express();
@@ -18,6 +19,57 @@ app.get('/loadwhiteboard', function(req, res) {
     res.end();
 });
 
+app.post('/upload', function(req, res) { //File upload
+    var form = new formidable.IncomingForm(); //Receive form
+    var formData = {
+        files : {},
+        fields : {}
+    }
+
+    form.on('file', function(name, file) {
+        formData["files"][file.name] = file;      
+    });
+
+    form.on('field', function(name, value) {
+        formData["fields"][name] = value;
+    });
+
+    form.on('error', function(err) {
+      console.log('File uplaod Error!');
+    });
+
+    form.on('end', function() {
+        progressUploadFormData(formData);
+        res.send("done");
+        //End file upload
+    });
+    form.parse(req);
+});
+
+function progressUploadFormData(formData) {
+    console.log("Progress new Form Data");
+    var fields = formData.fields;
+    var files = formData.files;
+    var whiteboardId = fields["whiteboardId"];
+
+    var name = fields["name"] || "";
+    var date = fields["date"] || (+new Date());
+    var filename = whiteboardId+"_"+date+".png";
+
+    fs.ensureDir("./public/uploads", function(err) {
+        var imagedata = fields["imagedata"];
+        if(imagedata && imagedata != "") { //Save from base64
+            imagedata = imagedata.replace(/^data:image\/png;base64,/, "").replace(/^data:image\/jpeg;base64,/, "");
+            console.log(filename, "uploaded");
+            fs.writeFile('./public/uploads/'+filename, imagedata, 'base64', function(err) {
+                if(err) {
+                    console.log("error", err);
+                }
+            });
+        }
+    });
+}
+
 io.on('connection', function(socket){
     socket.on('drawToWhiteboard', function(content) {
         socket.broadcast.emit('drawToWhiteboard', content);