servercode.js
var express = require('express');
var app = express();
app.get("/abc",function(req, res) {
res.send("Hello");
});
clientcode.html
<html>
<head>
<script type="text/javascript">
$.get("/abc", function(string) {
alert(string);
})
</script>
</head>
<body>
There is no as such body of this. Its just works. :)
</body>
</html>
I want to call the servercode.js script from my client. Both files are on the node server. So that I receive the alert Hello in my client.
Though my main aim is to call a function periodically that would be written in servercode.js file. But for the time being I am not even being able to receive the hello response from the server and my files are in firebase hosting.
I hope I am clear with my question.
Help me on this!! Thank you very much.
Related
Basicly I want to run a function when I clicked the button, but it works when I started the server and go to localhost one time, here's what's supposed to happen, after that localhost page doesn't load. (Unable to connect error)
If I remove the function there is no problem. How can I get it to work only when I click the button ?
Many thanks.
My func.js
const mongoose = require("mongoose");
const axios = require('axios');
async function func() {
//MyCodes
}
module.exports = {
func: func
}
My index.ejs
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<button type="button" onClick= <%= func.func() %> >Click</button>
//Other codes are independent the button
</body>
</html>
My res.render codeblocks in app.js
var func = require('./func');
app.get("/", (req, res) => {
res.render('index', {
cName: name,
symbol: symbol,
len: finds[0].result.length,
cPrice: price,
cDate: date,
func:func
});
});
});
})
You are misunderstanding. You cannot call an internal nodejs function(backend) from the html (frontend). If your frontend need to execute some backend operation like query to mongo, you have these options:
#1 client side rendering (Modern)
This is the most used in the modern world: Ajax & Api
your backend exposes a rest endpoints like /products/search who recieve a json and return another json
this endpoints should be consumed with javascript on some js file of your frontend:
html
<html lang="en">
<head>
<script src="./controller.js"></script>
</head>
<body>
<button type="button" onClick="search();" >Click</button>
</body>
</html>
controller.js
function search(){
$.ajax({
url:"./api/products/search",
type:"POST",
data:JSON.stringify(fooObject),
contentType:"application/json; charset=utf-8",
dataType:"json",
success: function(response){
...
}
})
}
Note 1: controller.js contains javascript for browser not for backend : nodejs
Note 2: ejs is only used to return the the initial html, so it is better to use another frameworks like:react, angular, vue
#2 server side rendering (Legacies)
In this case, ajax and js for browser are not strictly required.
Any event on your html should use <form> to trigger an entire page reload
You backend receives any parameter from the , make some operations like mongo queries and returns html instead json, using res.render in your case
Note
Ejs is for SSR = server side rendering, so add ajax could be complex for novices. In this case, use the option #2
You cannot use a nodejs function (javascript for server) in the client side (javascript for browser). Maybe some workaround are able to do that but, don't mix different things.
I'm trying to use an html page in order to test the connection with my server.
I've got no problem with my server.js
var http = require('http');
var url = require("url");
// Chargement de socket.io
var io = require('socket.io').listen(server);
var server = http.createServer(function(req, res) {
var page = url.parse(req.url).pathname;
// Quand un client se connecte, on le note dans la console
});
io.sockets.on('connection', function (socket) {
console.log('Un client est connecté !');
});
server.listen(8080);
My client should is an html page here
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Socket.io</title>
</head>
<body>
<h1>Communication test with socket.io !</h1>
<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>
<script src="http://localhost:8000/server_node/node_modules/socket.io/lib/socket.js"></script>
<script>
var socket = io.connect('http://localhost:8080');
</script>
</body>
</html>
Problem is, when I load the html client, I've got this error
socket.js:6 Uncaught ReferenceError: require is not defined
at socket.js:6
I'm not trying to implement a real client, I just want a simple page in order to do some connection test.
Thanks for your help
EDIT: Problem fixed, it was all because I wasn't loading the html file from the serverlike this fs.readFile('./ClientTest.html', 'utf-8', function(error, content) {
As this is just used to do some test, it's fine if it works this way; the client side will be with an other platform.
Sorry for that useless issue :(
You appear to be importing the server-side library on the client, you want to be importing the client-side one.
As per the docs, this is automatically served when socket.io runs on the server which you can import via
<script src="/socket.io/socket.io.js" />
I am beginner to node and express. In my current application the page is displaying using this code :
var app = express();
app.use(serveStatic('static', {'index': ['index.html']}));
and in static folder, there are there files:
css, index and a js file
Listening to 3000 port it is working normally.
But what if I want to access URL like this :
localhost:3000/name=someName
I want to use this name parameter in my js file which is available in static folder.
or suggest any other routing method to do that?
If you want to get the query parameters in your .js file it can be done. So the code would look like this:
Server (index.js)
"use strict";
var express = require("express");
var serveStatic = require('serve-static');
var app = express();
app.use(serveStatic('static', {'index': ['index.html']}));
app.listen(3000);
console.log("Static express server started");
HTML (/static/index.html)
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="https://code.jquery.com/jquery-3.3.1.js"></script>
<script type="text/javascript" src="test.js"></script>
</head>
<body onLoad="readParameters()">
<div>
<h3 id="1" >Loading..</h3>
</div>
</body>
</html>
Client side JavaScript (/static/test.js)
var readParameters = function()
{
console.log('Getting parameters..');
let params = (new URL(location)).searchParams;
console.log('Query parameters: ', params.toString());
var html = 'Query parameters: ';
for (let p of params) {
html += "<br/>" + p.toString();
}
$("#1").html(html);
}
Then you can test by entering:
http://localhost:3000/?test=value
Into your browser.
You should see:
Query parameters: test=value
on the index page.
The code tree should look like this:
root
¦ index.js
¦
+---static
index.html
test.js
3 Files:
/index.js (Node server side code)
/static/index.html (HTML)
/static/test.js (Test JavaScript file)
You can defined route like below,
router.get('/name=:id', function(req, res, next) {res.render('index', { title: req.params.id});});
Route parameters are named URL segments that are used to capture the values specified at their position in the URL. This captured values we can access with 'req.params' object. for reference https://expressjs.com/en/guide/routing.html
Following are the structure of my application
Inside prototype.js file i have following code:
(function(exports) {
exports.foo = function() {
return 'bar';
};
})((typeof process === 'undefined' || !process.versions) ? window.common = window.common || {} : exports);
app.js contains
var express = require('express'),app = express(),server = require('http').createServer(app),io = require('socket.io').listen(server),port = 3000,path = require('path');
var common = require('common/prototype');
console.log(common.foo());
// listening to port...
server.listen(port);
//Object to save clients data
var users = [];
app.use(express.static(path.join(__dirname, 'public')));
app.get('/', function (req, res) {
res.sendfile('/public/index.html');
});
index.html contains
<!doctype html>
<html lang="en">
<head>
<title>Socket.io Demo</title>
</head>
<body>
<script src="/socket.io/socket.io.js"></script>
<script src="/common/prototype.js"></script>
<script>
alert(window.common.foo()); //This line will gives me an error TypeError: window.common is undefined
</script>
</body>
</html>
Now i would like to print
Hello, I am bar from server and client as well.
Now i am able to print from server side using following line
var common = require('common/prototype');
console.log(common.foo());
But could not able to show alert on client side. could you please help me to find the root cause for the issue.
The root cause is that when you do <script src="/common/prototype.js"></script> in your HTML the file won't be fetched because the Express static middleware is only looking for files under your public folder.
A quick way to test this is to copy your prototype.js to your javascript folder inside public. Then update your script tag to reference the file as follows <script src="/javascripts/prototype.js"></script>
The thing to remember is that the JavaScript files that live under node_modules are not automatically available to the browser.
I'm having trouble getting the now.js chat client tutorial to work. (I've also followed this video almost exactly).
server.coffee:
fs = require 'fs'
http = require 'http'
now = require 'now'
server = http.createServer (req, res) ->
fs.readFile(
'index.html'
(err, data) ->
res.writeHead(
200
'Content-Type': 'text/html'
)
res.end(data)
)
server.listen 8080
everyone = now.initialize(server)
everyone.now.distributeMessage = (msg) ->
everyone.now.receiveMessage(#.now.name, msg)
index.html:
<html>
<head>
<title>nowjs title</title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript" src="https://raw.github.com/Flotype/now/master/lib/now.js"></script>
<script type="text/javascript">
$(document).ready(function() {
now.name = prompt("What's your name?", "");
now.receiveMessage = function(name, msg) {
return $("<div></div>").text("" + name + ": " + msg).appendTo("#msg");
};
return $("#send-button").click(function() {
now.distributeMessage($("#text-input").val());
return $("#text-input").val("");
});
});
</script>
</head>
<body>
<div id="msg"></div>
<input type="text" id="text-input">
<input type="button" value="Send" id="send-button">
</body>
</html>
When I load up the server with node server.js,
I get an error that says "require not defined" on line 1 of now.js. Consequently, the client side code can't find the variable 'now'.
I understand that 'require' is a node function, but how do I get the client to understand that?
Any help will be appreciated.
The file you're including in your client source (../Flotype/now/master/lib/now.js) is the Node server side code that is included in your node process when calling now = require 'now'.
So changing your included client source file from .../Flotype/now/master/lib/now.js to /nowjs/now.js will fix your problem.
Where does this /nowjs/now.js file come from?
When using NowJS (and many other npm packages that do client/server communication) you extend the server object. This is done with the line everyone = now.initialize(server) (Code Here).
What the initialize function does is wrap your server with the fileServer (Code Here) class in NowJS. This adds a resource under the "folder" nowjs which serves the client now.js file.
I got this error when trying to run nodejs file with js command instead of node.
Eg: if the nodejs file name is test.js, I was doing
js test.js
instead of
node test.js
I hope this helps too for people searching for this error.