Develop Reference

session data getting stored every time

Below is the API that basically stores data in session if not already present then returns an empty JSON, otherwise sends the session data stored corresponding to that mail:
app.use('/session', function(req, res) {
if (req.body.email in req.session) {
console.log("user data already available");
res.send(req.session[req.body.email]);
} else {
req.session[req.body.email] = {};
req.session[req.body.email]["email"] = req.body.email;
req.session[req.body.email]["gender"] = req.body.gender;
req.session[req.body.email]["dbname"] = req.body.dbname;
console.log("user session stored");
res.send({});
}
});
Below is the ajax call that I am making from my application. It is a cross domain call and I have set the response header accordingly.
$.ajax({
url: 'url/session',
type: "POST",
crossOrigin: true,
data: {
"email": "email",
"gender": "all",
"dbname": "dbname"
},
success: function(data) {
console.log("inside session api call success");
console.log(data)
}
});
});
Now the problem is that if I hit the API using postman, it works fine but when I use that in my application, it overwrites the session every time and returns empty json. What am I doing wrong?
edit : Figured out that each time ajax call is happening, past session data gets deleted for all emails ids.session value gets reset but still unable to figure out why this is happening.

Update a p element from a nodejs function

I need to send a value from a input form to a nodejs server, which triggers a calculation with this value and needs to update an p element with the result of the calculation on the client side.
How can this be done?
This is what i have:
//Server side:
app.post('/calculate/:id', function(req, res){
var title = 'Tax Calculation';
var tax= taxcalculation(req.params.id);
res.render('index', {
title: title,
tax: tax,
});
});
//Client side:
var income= document.getElementById("income");
var tax = document.getElementById("tax")
$(income).on('change', function() {
console.log("changed");
$.ajax({
type: 'POST',
url: '/calculate/'+income.value,
success: function() {
$('#tax').html('<%= tax %>');
},
error: function() { // if error occured
alert("Error occured, please try again");
},
});
});

Okay, so you don't give a lot of data, but this sounds as simple as sending a response with the results to the client side in your Node web service that does the calculations and append the result to the P element

Your server code to handle the ajax call should output a json response which will contain the content for the <p>. It should not re-render the whole index page. I don't do a lot of node.js so I'll leave that for you to figure out.
The ajax success function should accept a response as a parameter, and then operate on that response.
Assuming the server response to this ajax request is of the format {"tax": 15.99}:
$.ajax({
type: 'POST',
url: '/calculate/'+income.value,
success: function(response) {
if (response.tax || response.tax === 0) {
$('#tax').html(response.tax);
}
},
error: function() { // if error occured
alert("Error occured, please try again");
},
});

Trying to render a page from node js after making post request through angularjs

I am trying to render a page from nodejs after the post request from angular controller. However, the page doesn't load and it stays on the same page. There are no errors in the console. Moreover in the browser developer tools I can see page loaded under the Network--Preview Section.
Is this the correct or suggested way? I guess, the control comes back to controller rather than rendering the page from node.How Can we avoid this or is there a better way to do this?
Any help is appreciated.
Post request from controller:
$http({
method : "POST",
url: '/afterSignin',
data: {
"inputUsername": $scope.inputUsername,
"inputPassword": $scope.inputPassword
}
}).success(function(data)
{
if(data.statusCode==401)
{
$scope.msg = "Invalid Username or Password";
}
else
{
console.log(data.statusCode);
console.log("login successfull");
}
Server Side Code(afterSignIn.js)
mysql.fetchData(function(err,results){
if(err){
throw err;
}
else
{
if(results.length > 0){
console.log("valid Login");
res.render('successLogin', { data: results } , function(err, result) {
// render on success
if (!err) {
res.end(result);
}
// render or error
else {
res.end('An error occurred');
console.log(err);
}
});
console output:
Connection closed..
DB Results:[object Object]
valid Login
[0mPOST /afterSignin [32m200 [0m103.425 ms -
Chrome Console Output

Look at this answer
There are a number of good solutions to this. Probably the easiest is to replace the URL of window:
$http({
method : "POST",
url: '/afterSignin',
data: {
"inputUsername": $scope.inputUsername,
"inputPassword": $scope.inputPassword
}
}).success(function(data){
if(data.statusCode==401) {
$scope.msg = "Invalid Username or Password";
}else {
console.log(data.statusCode);
// Interesting part, redirect the user
$window.location = '/successLogin'
}
});
As you can see, after receiving a response that indicates that the login was successful, you can redirect the user on the client side. (You have to inject $window as a dependency of the service/controller.)
A better solution would be to use a client side router package, e.g. ui-router (you should go this way).

Array is flattened when it's sent through AJAX jQuery request

I have the following endpoint written in Express, using the body-parser middleware.
app.post("/api/poll/new",api.NewPoll);
api.NewPoll = function(req,res){
if(!req.body) return res.status(400).send("MISSING BODY");
console.log(req.body,typeof(req.body));
if(!req.body.name) return res.status(400).send("MISSING NAME");
if(!req.body.options) return res.status(400).send("MISSING OPTIONS");
//rest of the endpoint goes here
};
The data that the endpoint expects looks like this:
{
"name":"Poller",
"options":[
{
"name":"Jojo's Bizarre Adventure",
"desc":"A great show"
},
{
"name":"Bakemonogatari",
"desc":"A real good show"
},
}
When I send this data through Postman, everything works. req.body.options exists and is an array. However, when I do the exact same thing in a jQuery AJAX call, the result is signficantly different:
var payload = {
name:"Poller",
options:g.newPollInfo
//g.newPollInfo contains the same array
}
$.ajax({
method:"POST",
url:"/api/poll/new",
data:payload,
success:function(data){
console.log(data);
},
error:function(req, status, error){
console.log(req,status,error);
}
});
I get a 400 error, reporting missing Options. The printed req.body looks like this:
{ name: 'Poller',
'options[0][name]': 'Jojo'\s Bizarre Adventure',
'options[0][desc]': 'A great show',
'options[1][name]': 'Bakemonogatari',
'options[1][desc]': 'A real good show' } 'object'
I have never had this problem before. The problem is not in express, as a request through Postman using the same data and it works. The only problem I can think of lies in the fact that the request is made from an iframe serviced through a secure connection, but that doesn't make sense.
I have no idea what causes this error.

According to both these questions, the problem is solved specify the header type on the AJAX Request and stringify.
$.ajax({
method:"POST",
url:"/api/poll/new",
data:JSON.stringify(payload),
contentType:"application/json",
success:function(data){
console.log(data);
},
error:function(req, status, error){
console.log(req,status,error);
}
});

AJAX post data almost saving to the db?

Testing the modules, the AJAX is posting properly in the browser's console.log, and the Node.js/express4 mongoose .save method is saving properly into MongoDB (testing with Postman - REST Client)
For some reason, the AJAX post data has yet to make it to the db, though it accurately logs the data..
$(document).ready(function(){
$('#SubmitBtn').click(function() {
var message = $( "#message" ).val();
console.log(message); // logs as the "user's message"
var AjaxPostData = {'message' : message};
console.log(AjaxPostData); // logs as [object Object]
// make an ajax call
$.ajax({
dataType: 'json',
data: AjaxPostData,
type: 'post',
url:"http://localhost:4200/api/v1/stories",
success: foundAllSuccess,
error: foundAllFailure
});
console.log(AjaxPostData.message); // logs as the "user's message"
});
});
Express4 routing:
var router = express.Router(); // an instance of the express Router
var Story = require('./app/models/story'); // load the mongoose model
router.route('/stories')
// create a story (accessed at POST http://localhost:4200/api/v1/stories)
.post(function(req, res) {
var story = new Story(); // create a new instance of the Story model
story.message = req.body.message; // set the message, from the request
console.log(req.body.message); // logs with Postman, yet the ajax post
// save the story, and check for errors
story.save(function(err) {
if (err)
res.send(err);
res.json({ message: 'Story "' + story.message + '" Created' });
});
})
app.use( '/api/v1', router ); // all of the routes are prefixed

Replace data: AjaxPostData,
With data : JSON.stringify(AjaxPostData),
I dont believe the data is being passed correctly and thats why it sends at [Object object]

Turns out that the ajax click event needed e.preventDefault(); or return false;
$('#SubmitBtn').click(function(e) {
e.preventDefault();
// do something
});
$('#SubmitBtn').click(function() {
//do something
return false;
});
Either work in this case..though here's a great post on the differences: event.preventDefault() vs. return false