I am trying to practice making a get request with vanilla javascript to express server, but I am stuck in receiving the request in express js (my terminal does not print anything in my get request call).
Am I missing something that my express did not listen to my get request at all?
front end:
(function () {
var retrieve = document.getElementById('retrieve'),
results = document.getElementById('results');
retrieve.addEventListener('click', function (e) {
var oReq = new XMLHttpRequest();
console.log('GET', e.target.dataset.url);
oReq.open('GET', e.target.dataset.url, true);
oReq.onload = function () {
console.log('Inside the onload event');
if(oReq.readyState === 4){
if(oReq.status === 200){
console.log(oReq.reponseText, "pass");
}
else{
console.error(oReq.statusText);
}
}
};
oReq.onerror = function(e){
console.error(oReq.statusText, "error");
}
oReq.send(null);
});
}());
<h1>Vanilla Ajax without jQuery</h1>
<button id="retrieve" data-url="/">Retrieve</button>
<p id="results"></p>
express code:
var express = require('express');
var path = require("path");
var bodyParser = require('body-parser');
var morgan = require('morgan');
var db = require('./db');
var cors = require("cors");
var app = express();
app.use(cors());
app.use(bodyParser.json());
app.use('/', express.static(path.join(__dirname, '../client')));
app.get("/", function(req,res){
console.log("get");
});
app.listen(3000, function () {
console.log('Example app listening on port 3000!')
})
Related
im trying to do a simple ajax call but somehow it doesnt work.I cant figure it out, would be nice if someone could help me.
Server script :
var express = require('express');
var app = express();
var path = require('path');
var port = 8888;
//allow to use static files
app.use(express.static("public"));
//listen to smth
app.get('/test1', function (req, res) {
res.send('GET request to the homepage');
});
//start server
app.listen(port);
console.log("Server running on port" + port);
HTML Button that runs a client based JS
<button onclick="callServerSideScript('key','port','address','username','password','gem','proxy','crypt')" type="button" id="build">Get build</button>
Client based JS :
function callServerSideScript(key,port,address,username,password,gem,proxy,crypt){
keyVal = document.getElementById(key).value;
portVal = document.getElementById(port).value;
addressVal = document.getElementById(address).value;
userVal = document.getElementById(username).value;
pwVal = document.getElementById(password).value;
gemVal = document.getElementById(gem).checked;
proxyVal = document.getElementById(proxy).checked;
crytpVal = document.getElementById(crypt).checked;
httpRequest = new XMLHttpRequest();
httpRequest.open('POST', '/test1');
httpRequest.send('some data');
}
Normally it should do a /test1 request to the server and the server should react to it? I am missing something?
eighter do httpRequest.open('GET', '/test1'); (client) or app.post('/test1', handler); (server). but if your sending a POST request and the server expects a GET request it just gets 404'd
I am making an api call and recieving the data, however, I am having trouble sending the data back to my js file. I tried using res.send but I am getting an error. I can't seem to figure out how to send the information back to the javascript file. (I took my key out of the request link. For security reasons, however, I am getting the data back from the api call). The only problem I am having is returning the data to the frontend javascript file.
This is the Javascript file that sends the original request:
/ ********** options button function makes api call to get selected cities forecast *****************
function getCityForecast(e){
var id = document.getElementById('cities');
var getValue = id.options[id.selectedIndex].value;
var suffix = getValue + ".json";
var newObj = JSON.stringify({link : suffix});
var xhr = new XMLHttpRequest();
xhr.open("POST", "http://localhost:3000/", true);
xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xhr.send(newObj);
xhr.onreadystatechange = function(){
if(xhr.readyState === 4){
console.log(xhr.response);
console.log('recieved');
} else {
console.log('error');
}
}
}
My server.js file looks like this:
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var http = require('http');
var path = require('path');
var request = require('request');
// ****************** Middle Ware *******************
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.use(express.static(__dirname + '/public'));
var retrievedString;
// **************** Post Request *******************
app.post('/', function(req, res){
var link = "http://api.wunderground.com/api/key/forecast";
retrievedString = link.concat(req.body.link);
request = http.get(retrievedString , function(res){
var body = '';
res.on('data', function(data){
body += data;
});
res.on('end', function(){
var parsed = JSON.parse(body);
console.log(parsed.forecast.txt_forecast);
res.send(parsed.forecast.txt_forecast);
});
})
.on('error', function(e) {
console.log("Got error: " + e.message);
});
});
app.listen(3000, function() { console.log('listening')});
You are overloading the definition of the variable res which is also what you called the response variable for your Express route handler method. In the callback function of the request, use a different name for that variable - for example:
request = http.get(retrievedString , function(resDoc){
Send a parameter(URL) from another script through recursion to this script.
var express = require('express');
var request = require('request');
var cheerio = require('cheerio');
var mongodb = require('mongodb');
var app = express();
var MongoClient = mongodb.MongoClient;
// Connection URL. This is where your mongodb server is running.
var murl = 'mongodb://localhost:27017/getData';
url = '';
app.get('/getData', function(req, res){
firstCall(req,res)
//console.log("cookie",req.cookies);
})
var firstCall = function(req, res, data){
console.log("URL: ", url);
res.send('Check your console!');
}
app.listen('3000')
console.log('Magic happens on port 3000');
module.exports = function(app) {
app.get('/getData', function() {});
};
I want this code to act as backbone or logic board. And some other file should be able to trigger this logic board file by adding the URL to this file.
Like we pass parameters to function to call. How do I do it here.
I'm writing a websocket server using nodejs-ws module, but the server can only be at the root of the server, so how I can make it at a child router like localhost:3000/chat?
I need your help, thanks a lot!
Working example:
var ws = require('ws');
var http = require('http');
var httpServer = http.createServer();
httpServer.listen(3000, 'localhost');
var ws1 = new ws.Server({server:httpServer, path:"/chat"});
ws1.on('connection', function(){
console.log("connection on /chat");
});
var ws2 = new ws.Server({server:httpServer, path:"/notifications"});
ws2.on('connection', function(){
console.log("connection on /notifications");
});
could you please tell me how to use this in express?
To route websockets with Express I'd rather use express-ws-routes
var express = require('express');
var app = require('express-ws-routes')();
app.websocket('/myurl', function(info, cb, next) {
console.log(
'ws req from %s using origin %s',
info.req.originalUrl || info.req.url,
info.origin
);
cb(function(socket) {
socket.send('connected!');
});
});
I'm trying to send a JSON object from javaScript to node.js server. I'm using a standard XMLHttpRequest to send it from javascript and a standard node.js code.
Two codes seem to be communicating normally however the node.js always gives me an empty JSON object. I'm not really sure what am I doing wrong.
This is my javascript code:
<html>
<head>
<script>
function xhrPost() {
var data = {"name":"John", "time":"2pm"};
var xhr = new XMLHttpRequest();
xhr.withCredentials = true;
xhr.addEventListener("readystatechange", function () {
if (this.readyState === 4) {
console.log(this.responseText);
}
});
xhr.open("POST", "http://[serverIP]:8080/addUser");
xhr.setRequestHeader("cache-control", "no-cache");
xhr.setRequestHeader("content-type", "application/json;charset=UTF-8");
xhr.send(JSON.stringify(data));
}
</script>
</head>
<body onload="xhrPost()">
</body>
</html>
and this is my node.js code:
var express = require("express");
var myParser = require("body-parser");
var app = express();
app.use(myParser.urlencoded({extended : true}));
app.post("/addUser", function(request, response) {
console.log(request.body); // this line allways produce {}
response.send("Message received.");
response.end();
});
app.listen(8080);
You have to use myParser.json() as a middleware. See more about it in https://github.com/expressjs/body-parser#bodyparserjsonoptions
After following line:
var myParser = require("body-parser");
You should add on more line as:
var myParser = require("body-parser");
app.use(myParser.json());// parse application/json
This was the most helpful stackoverflow page to solve my problem as well.
I was trying to get form fields, formulate them into a JSON on the client, then send to the server to use the fields for a MySQL call to a separate database.
Object {name: "", reps: "1", weight: "1", date: "", lbs: "0"}
I was able to get the object logging correctly on the client, yet every time I tried to send the data to the server,
console.log(req.body);
Would always return on the server as either
{}
undefined
Server side my setup with functioning data passing is
var express = require('express');
var mysql = require('./dbcon.js');
var app = express();
var handlebars = require('express-handlebars').create({defaultLayout:'main'});
var request = require('request');
var myParser = require("body-parser");
var async = require('async');
app.set('view engine', 'handlebars');
app.set('port', Number(process.env.PORT || 3000));
app.use(myParser.json());
app.use(express.static('public'));
app.engine('handlebars', handlebars.engine);
On my client side js file, I have a function upon form submit that does:
var data = {
"name":document.getElementById("fname").value,
"reps":document.getElementById("freps").value,
"weight":document.getElementById("fweight").value,
"date":document.getElementById("fdate").value,
"lbs":bool
};
...
req.open("POST", "/insert", true);
req.setRequestHeader("content-type", "application/json;charset=UTF-8");
...
req.send(JSON.stringify(data));