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A simple "voting" example with node.js
<html>
<body>
<H2>Are you sure to overwrite your votes?</H2>
<form action="" method="post" enctype="multipart/form-data">
<fieldset>
<input type="submit" name="action" value="Update" />
<input type="submit" name="action" value="Cancel" />
</fieldset>
</form>
</body>
</html>
<html>
<body>
<H1>Presentation Voting for OU Deep Learning 2017</H1>
Please note that 5 is highest and 1 is lowest.
<form action="" method="post" enctype="multipart/form-data">
<fieldset>
<label for="name">Your name:</label>
<select name="name" id="name">
<option disabled selected>Please pick one</option>
<option>Aakash</option>
<option>Ahmad A</option>
<option>Ahmad M</option>
<option>Dong</option>
<option>Muhanad</option>
<option>Naim</option>
<option>Obada</option>
<option>Siraj</option>
<option>Soubhi</option>
<option>Tamer</option>
<option>Varun</option>
</select>
<label for="presenter1">Score for Aakash</label>
<select name="aakash" id="presenter1">
<option>1</option>
<option>1.5</option>
<option>2</option>
<option>2.5</option>
<option selected="selected">3</option>
<option>3.5</option>
<option>4</option>
<option>4.5</option>
<option>5</option>
</select>
<label for="presenter2">Score for Soubhi</label>
<select name="soubhi" id="presenter2">
<option>1</option>
<option>1.5</option>
<option>2</option>
<option>2.5</option>
<option selected="selected">3</option>
<option>3.5</option>
<option>4</option>
<option>4.5</option>
<option>5</option>
</select>
<input type="submit" value="Submit Scores" />
</fieldset>
</form>
</body>
</html>
// vote from students
var express = require('express');
var formidable = require('formidable');
var mysql = require('mysql');
var path = require("path");
var util = require('util');
var app = express();
var pool = mysql.createPool({
connectionLimit : 100, //important
host : 'localhost',
user : 'root',
password : '=[-p0o9i',
database : 'votes',
debug : false
});
var Translate={};Translate.translate_map={" ":"_"};
String.prototype.underscorize=function() //{return this.replace(/[^A-Za-z0-9\[\] ]/g,function(a){return Translate.translate_map[a]||a})};
{
var newstr = this.replace(/ /g,'_');
return newstr.toLowerCase();
}
function put_score_to_database(req,res,fields) { // actually putting score after confirmation
pool.getConnection(function(err,connection){
if (err) {
res.json({"code" : 100, "status" : "Error in connection database"});
return;
}
console.log('connected as id ' + connection.threadId);
presenter1=Object.keys(fields)[1];
presenter2=Object.keys(fields)[2];
name=fields['name'].underscorize();
connection.query("UPDATE votes SET "+name+'='+fields[presenter1]+" WHERE speaker='"+presenter1+"';",function(err,rows){
});
connection.query("UPDATE votes SET "+name+'='+fields[presenter2]+" WHERE speaker='"+presenter2+"';",function(err,rows){
connection.release();
});
connection.on('error', function(err) {
res.json({"code" : 100, "status" : "Error in connection database"});
return;
});
});
}
// try adding score to database
function add_score_to_database(req,res,fields) {
var form = new formidable.IncomingForm();
var user_id = req.param('id');
form.parse(req, function (err, fields, files) {
pool.getConnection(function(err,connection){
if (err) {
res.json({"code" : 100, "status" : "Error in connection database"});
return;
}
console.log('connected as id ' + connection.threadId);
if (fields['name']== undefined){
res.redirect('/');
return;
}
presenter1=Object.keys(fields)[1];
presenter2=Object.keys(fields)[2];
name=fields['name'].underscorize();
connection.query("select "+name+" from votes where speaker='"+presenter1+"';",function(err,rows){
connection.release();
if(!err) {
if (rows[0][name]!=null) {
res.redirect('/confirm?name='+fields['name']+'&presenter1='+presenter1+
'&score1='+fields[presenter1]+'&presenter2='+presenter2+
'&score2='+fields[presenter2]);
}
else {
put_score_to_database(req,res,fields);
res.end('Thank you for voting!');
}
}
});
connection.on('error', function(err) {
res.json({"code" : 100, "status" : "Error in connection database"});
return;
});
});
});
}
app.get("/",function(req,res){
res.sendFile(path.join(__dirname+'/form.html'));
});
app.post("/",function(req,res){
// handle_database(req,res);
// processAllFieldsOfTheForm(req,res);
add_score_to_database(req,res,null);
});
function getParameters(req){
var name = req.param('name');
var presenter1 = req.param('presenter1');
var presenter2 = req.param('presenter2');
var score1 = req.param('score1');
var score2 = req.param('score2');
if (name == undefined ||presenter1 == undefined
|| presenter2== undefined||
score1 == undefined || score2 == undefined)
return null;
else
return {name:name,presenter1:presenter1,
presenter2:presenter2,score1:score1,score2:score2};
}
app.get("/confirm",function(req,res){
params=getParameters(req);
if (params==null)
res.redirect('/');
res.sendFile(path.join(__dirname+'/confirm.html'));
})
app.post("/confirm",function(req,res){
var {name,presenter1,presenter2,score1,score2}=getParameters(req);
var form = new formidable.IncomingForm();
form.parse(req, function (err, fields, files) {
myfield={name: name};
myfield[presenter1]=score1;
myfield[presenter2]=score2;
if (fields.action=='Update')
{
put_score_to_database(req,res,myfield);
res.end('Thank you for updating your votes!');
return;
}
else
res.redirect("/");
});
})
app.listen(3000);
// ---- not use ---
// example for handling mysql
function handle_database(req,res) {
pool.getConnection(function(err,connection){
if (err) {
res.json({"code" : 100, "status" : "Error in connection database"});
return;
}
console.log('connected as id ' + connection.threadId);
connection.query("select * from votes",function(err,rows){
connection.release();
if(!err) {
res.json(rows);
}
});
connection.on('error', function(err) {
res.json({"code" : 100, "status" : "Error in connection database"});
return;
});
});
}
// example for parse form
function processAllFieldsOfTheForm(req, res) {
var form = new formidable.IncomingForm();
var user_id = req.param('id');
form.parse(req, function (err, fields, files) {
//Store the data from the fields in your data store.
//The data store could be a file or database or any other store based
//on your application.
res.writeHead(200, {
'content-type': 'text/plain'
});
res.write('received the data:\n\n');
res.write(fields.name+'\n');
res.end(util.inspect({
fields: fields,
files: files,
id: user_id
}));
});
}
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