This is to start with a very basic page: HTML Form, a button, and a div-box.
.click of the button would POST the Form data through AJAX.
The data is to be stored in MongoDB, and retrieved into the div-box without a page-refresh.
AJAX from index.html:
$(document).ready(function()
{
// handle button clicks
$('#buttonID').click(function() {
// make an ajax call
$.ajax({
dataType: 'jsonp',
jsonpCallback: '_wrapper',
data: $('#formID').serialize(),
type: 'POST',
url: "http://localhost:9999/start",
success: handleButtonResponse,
});
});
function handleButtonResponse(data)
{
// parse the json string
var jsonObject = JSON.parse(data);
$('#reponseID').append( jsonObject.message );
}
});
app.js:
var express = require('express'),
app = express();
cons = require('consolidate');
MongoClient = require('mongodb').MongoClient,
Server = require('mongodb').Server;
app.engine('html', cons.swig);
app.set('view engine', 'html');
app.set('views', __dirname + "/views");
var mongoclient = new MongoClient(new Server('localhost', 27017,
{ 'native_parser' : true }));
var db = mongoclient.db('database_name');
app.get('/', function (req, res) {
db.collection('collectionName').find({}, function (err, doc) {
res.render('index', doc);
});
response.writeHead(200, {"Content-Type:": "application/json"});
var submittedPost = {};
submittedPost['message'] = 'Proof that Node and Mongo are working..';
response.write( "_wrapper('" );
response.write( JSON.stringify(submittedPost) );
response.write( "')");
response.end();
});
app.get('*', function (req, res) {
res.send("404..", 404);
});
mongoclient.open(function (err, mongoclient) {
if (err) throw err
app.listen(9999);
console.log("Express server started on port 9999");
});
How/Where does the JSON connect to/from MongoDB?
Also, does Express require a templating engine, such as Consolidate? If so, how/where does that fit in?
Few suggestions
Regarding the ajax call in index.html
If your index.html is served by the same server, then please don't use a cross domain call. The url property in $.ajax could be a relative url like /start.
Also you can think of not using jsonp request.
the call could be like
$.ajax({
dataType: 'json',
data: $('#formID').serialize(),
type: 'POST',
url: "./start",
success: handleButtonResponse,
});
How/Where does the JSON connect to/from MongoDB?
In you ajax call you are requesting for ./start, So the same route should be made in your express server. like
app.get('/start', function (req, res) {
db.collection('collectionName').insert({req.data}, function (err, doc) {
//rest of code
});
});
does Express require a templating engine, such as Consolidate? If so, how/where does that fit in?
You have many options for templating like jade,ejs,hbs and so on.
If you use jade or any of them your html rendering code in express routes will get simplified.
without a templating engine
response.writeHead(200, {"Content-Type:": "application/json"});
var submittedPost = {};
submittedPost['message'] = 'Proof that Node and Mongo are working..';
response.write( "_wrapper('" );
response.write( JSON.stringify(submittedPost) );
response.write( "')");
response.end();
with a templating engine like jade (now pug)
var submittedPost = {};
submittedPost['message'] = 'Proof that Node and Mongo are working..';
response.json(submittedPost);
also with templating engines you can render templates with server side variables and you can access them inside your templates like
app.get('/mypage', function (req, res) {
res.render('mytemplate_page',{template_variable:some_variable});
});
and you can use template_variable inside the template for looping through or displaying.
Related
I am using Node.js with Express and MongoDB.
I have a page, '/score' that calculates the user's score from a quiz taken on the previous page. The '/score' route is below:
app.get('/score', stormpath.getUser, function(req, res) {
var quiz = req.session.mostRecentQuiz;
db.collection('quizzes').find(quiz).toArray(function (err, docs) {
assert.equal(err, null);
var quiz;
docs.forEach(function (doc) {
quiz = doc.quiz;
});
res.render('score', {quiz: quiz});
});
db.collection('users').update({user: req.user.username}, { $set: {"mostRecentQuiz": quiz } }, function (err, result) {
if (err) throw err;
console.log(result);
} );
});
After getting the quiz answers from the DB, I use some client-side JavaScript on the /score page to calculate the user's score and then report it to the user. However, I would like to get that same score back to my MongoDB, but I am not sure how best to accomplish that.
Can I use AJAX to accomplish this, or would it be better to redirect to a new page?
If you're already using Express, the simplest way would be to define a route for updating the score. Then you can send the data to the server via AJAX.
In order to parse the request parameters install the body-parser module.
Server:
var bodyParser = require('body-parser')
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.put('/score', stormpath.getUser, function (req, res) {
console.log(req.body); // there should be your received data
// save it to the database
db.collection('yourcollection').updateOne(
{}, // your query for updating the data in the wished field
function(err, results) {
if(err) { return res.json(err); };
return res.json(results);
});
});
Client - if you're using jQuery:
$.ajax({
url: '/score',
type: 'PUT',
contentType: 'application/json',
data: {'score':1000}, // put here your data to send it to the server
success: function(data){
console.log(data);
}
});
Some documentation:
MongoDB update: https://docs.mongodb.com/getting-started/node/update/
jQuery AJAX: https://api.jquery.com/jquery.ajax/
Hey guys I am new to node, and trying to setup a file/image upload script.
I was able to setup node on my VPS and following this example I also set up the app and it is working great.
https://coligo.io/building-ajax-file-uploader-with-node/
It is using formidable and express
However I'd love to also parse a form where people can add their name and the files get uploaded into a folder containing their names.
I was able to get the folder creation working using mkdirp, however even after many hours of research (formidable api, express api, and more) I can't get the form to parse the name.
I suspect that the upload.js (which sends the data to the node app) does not work.
At the moment a new folder with a random string is created for each upload, but I'd love to be able to parse the entered formname.
Any idea how to get it working? I'd appreciate any help/hints.
app.js
var express = require('express');
var app = express();
var path = require('path');
var formidable = require('formidable');
var fs = require('fs');
var mkdirp = require('mkdirp');
var crypto = require("crypto");
app.use(express.static(path.join(__dirname, 'public')));
app.get('/', function(req, res){
res.sendFile(path.join(__dirname, 'views/index.html'));
});
app.post('/upload', function(req, res){
var ordner = crypto.randomBytes(20).toString('hex');
mkdirp('/home/myfolder/fileupload/'+ordner, function (err) {
if (err) console.error(err)
else console.log(ordner)
});
var form = new formidable.IncomingForm();
form.multiples = true;
form.uploadDir = path.join(__dirname, '/'+ ordner);
form.on('file', function(field, file) {
fs.rename(file.path, path.join(form.uploadDir, file.name + Date.now()+'.jpg'));
});
form.on('field', function(field, userName) {
console.log(userName);
});
form.on('error', function(err) {
console.log('An error has occured: \n' + err);
});
form.on('end', function() {
res.end('success');
});
form.parse(req);
});
var server = app.listen(3000, function(){
console.log('Server listening on port 3000');
});
Thanks
The upload.js is unchanged and I simply added another input to the view.
You can do this by sending the parameters through the POST like so
app.post('/upload/:userName', function(req, res){
var username = req.params.userName
mkdirp('/home/myfolder/fileupload/'+username, function (err) {
if (err) console.error(err)
else console.log(ordner)
});
The rest of your code pretty much stays the same.
EDIT: Your ajax would look something like this
var username = 'GetThisValueFromTheUser'
$.ajax({
url: '/upload'+username,
type: 'POST',
data: formData,
processData: false,
contentType: false,
success: function(data){
console.log('upload successful!');
}
});
Note: You can send parameters by using /:parameter in your POST or GET requests, from then on it is easy to use those parameters however you want.
I'm running a server in nodejs with express to serve an html form within the file index.html to a client like this:
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser());
app.get('/', function(req, res){res.sendfile('index.html');});
app.post('/', function(req, res){
res.json(req.body);
});
app.listen(8080);
req.body gives me the form input. Now I need to send back req.body to the client, and to do this I'm using ajax on the client side (inside index.html) like this:
var data;
$('#submit').click(function()
{
console.log('Button Clicked');
$.ajax({
url: '/',
type:'POST',
data: data,
dataType: 'json',
}).done(function(data) {
console.log(data);
});
})
However when I click the button submit I get Object {} in the browser console and not the form input.
What am I missing here?
There are two issues in your code:
First, as the comments mention, bodyParser() is deprecated, you should be using the specific bodyParser middlewares (json, text, urlencoded, raw). So in your case:
app.use(bodyParser.json())
Second, your client side call to jQuery.ajax should stringify your data. Like this:
$('#submit').click(function()
{
console.log('Button Clicked');
$.ajax({
url: '/',
type:'POST',
data: JSON.stringify(data),
dataType: 'json',
}).done(function(data) {
console.log(data);
});
})
I'm hitting a facebook graph search URL, in Parse Express. The call is made with a Parse.Cloud.httpRequest.
I get a 500 Internal Server Error response, and when I look in the logs I see:
an error saying that the httpRequest has no method named success: (even though the code i'm using is based right off examples on Parse.com).
The basic JSON data is there successfully retrieved but the error has prevented the function completing.
Here's the code, all tips appreciated:
// These two lines are required to initialize Express in Cloud Code.
var module = require('cloud/jsonml.js');
var Buffer = require('buffer').Buffer;
var express = require('express');
var app = express();
// Global app configuration section
app.set('views', 'cloud/views'); // Specify the folder to find templates
app.set('view engine', 'ejs'); // Set the template engine
app.use(express.bodyParser()); // Middleware for reading request body
app.get('/hello', function(request, response) {
Parse.Cloud.httpRequest({
url: 'a-facebook-graph-url',
success: function(httpResponse) {
console.log(httpResponse.data);
response.success(httpResponse.data);
var xml = module.stringify(httpResponse.data);
var base64xml = xml.data.base64;
console.log(base64xml);
res.render('hello.ejs',{ message: base64xml });
},
error:function(httpResponse){
console.error('Error:' + httpResponse.message);
response.error("Failed to parse feed");
res.render('hello.ejs',{ message: httpResponse.message });
}
});
});
app.listen();
I just use promises. This seems to work for me:
Parse.Cloud.httpRequest({
url: 'a-facebook-graph-url'
}).then(function(httpResponse) {
console.log(httpResponse.text);
var xml = module.stringify(httpResponse.data);
var base64xml = xml.data.base64;
res.render('hello',
{
message: base64xml
});
}, function(httpResponse) {
console.error('Request failed with response code ' + httpResponse.status);
});
More info from parse website here
How do I parse my JSON with external middleware now that Express doesn't carry a body parser?
For a while, I was using Express bodyParser to receive and respond to JSON posts to the server. Each time I started up the server, express said something about bodyParser being removed soon, and sure enough, I've updated and now JSON requests seem to be showing null.
So I didn't understand how middleware worked, and had followed an express tutorial to use the body parser. Now, using separate body parser middleware, it seems I'm doing it wrong.
Before, my syntax was:
app.use(express.bodyParser());
Now, with the module body-parser as middleware, it's like this:
app.use(bodyParser.json());
And an example as a whole:
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
function listen() {
app.use(bodyParser.json());
app.post('/login', function (req, res) {
var username = req.body.username;
var password = req.body.password;
console.log('User ' + username + ' is attempting login...');
validate(username, password, function (err, result) {
if (err) loginFail(req, res, err);
else loginSucceed(req, res, result);
});
});
app.listen(3333);
}
listen();
I tried express.json() as the middleware, but that triggers the fatal error:
Error: Most middleware (like json) is no longer bundled with Express
and must be installed separately. Please see
https://github.com/senchalabs/connect#middleware.
That link leads to the body-parser middleware that I'm using via app.use(bodyParser.json()).
Update:
Using bodyParser.json() results in no error, but the data values are null:
User undefined is attempting login...
My client code should be fine, but here it is for completeness:
function sendLogin() {
popLogCreds(creds);
var loginCredentials = {
"username": creds.username,
"password": creds.password
};
console.log("Sending login credentials: " +
JSON.stringify(loginCredentials, null, 4));
request = $.ajax({
url: "http://54.186.131.77:3333/login",
type: "POST",
crossDomain: true,
data: loginCredentials,
dataType: "json",
error: function () {
postError("Uh Oh! The Officeball server is down.");
},
success: function (data) {
var ParsedData = data;
sessionStorage.username = creds.username;
sessionStorage.password = creds.password;
sessionStorage.fname = ParsedData.fname;
sessionStorage.lname = ParsedData.lname;
sessionStorage.rank = ParsedData.rank;
console.log(sessionStorage);
window.location.replace("app.html");
}
});
}
Which results in:
Sending login credentials: {
"username": "jonathan#evisiion.com",
"password": "J******!"
}
And then the result is the POST's error output, which is, as above:
error : function () {
postError("Uh Oh! The Officeball server is down.");
}
Don't take that error message literally. Just means an error happened. The server is, in fact, getting that request, as shown up above.
By default, $.ajax() sends data URL-encoded as mentioned in the description of the processData option:
By default, data passed in to the data option as an object (technically, anything other than a string) will be processed and transformed into a query string, fitting to the default content-type "application/x-www-form-urlencoded".
The body-parser that corresponds to that Content-Type and format is urlencoded():
app.use(bodyParser.urlencoded());
If you'd rather use JSON for the request, you'll need to provide the data already formatted as such along with a matching contentType that bodyParser.json() recognizes:
request = $.ajax({
url: "http://54.186.131.77:3333/login",
type: "POST",
crossDomain: true,
data: JSON.stringify(loginCredentials),
contentType: 'application/json',
dataType: 'json'
// ...
});
Note for cross-domain: With these modifications, the server will have to handle preflight OPTIONS requests for the route.
And, note that a bodyParser isn't needed for HEAD or GET requests as the data is included in the URL rather than the body. Express parses that separately into req.query.
In your node code,
make sure you put these two lines of code
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyparser.urlencoded({ extended: false }));
app.use(bodyparser.json());
......then your other code follows..
enjoy...