Send data to Node.js server from HTML form

javascript html node.js post

40,692

Solution 1

The simple answer is <form method="get">. The browser will turn the form data into query string parameters that you're already handling.

If you need to POST, HTML forms are posted as the request entity-body. In node, a ClientRequest (the request variable in your example) emits a data event every time a chunk of the body arrives at the server. You will not receive the entire body at once. You must buffer until you've received the entire body, then parse the data.

This is hard to get right because of things like chunked vs normal Transfer-Encoding and the different ways browsers can submit form data. I'd just use formidable (which is what Express uses behind the scenes anyway), or at least study how it handles form posts if you absolutely must implement your own. (And really, do this only for educational purposes – I can't stress enough that you should use formidable for anything that might end up in production.)

Solution 2

Your jade form (assuming you're using express) should look like this:

form(action="/" method="post")
    input( name="whateverSearch" placeholder="search" autofocus)

Then to pass the newly submitted datapoint whateverSearch you use req.body to find it (see below). Here, I've taken the data point and logged it to the console, and then submitted it to the DOM, as well as the title for the page.

router.post('/', function(req, res) {
    whateverSearch = req.body.whateverSearch;
    console.log(whateverSearch);
    res.render('index', { title: 'MyApp', inputData: whateverSearch});
});

Solution 3

I solved my problem this way:

sum.js:

var http = require("http");
var url = require("url");

http.createServer(function(request, response){
    response.writeHead(200, {"Content-Type":"text/plain"});
    var params = url.parse(request.url,true).query;

    console.log(params);

    var a = params.number1;
    var b = params.number2;

    var numA = new Number(a);
    var numB = new Number(b);

    var sum = new Number(numA + numB).toFixed(0);

    response.write(sum);
    response.end();
}).listen(10001);

Index.html:

<html>
    <head>
            <title> Pedir random </title>

            <script type="text/javascript">
                function operacion(){
                        var n1 = document.getElementById("num1").value;
                        var n2 = document.getElementById("num2").value;

                        location.href = "http://localhost:10001" + "?number1=" + n1 + "&number2=" + n2;
                }
            </script>

    </head>

    <body>
            <h1>Inserte dos números </h1>
            <form id="forma1"> 
                <input type="text" id="num1"></input>
                <input type="text" id="num2"></imput>
                <input type="button" onClick="operacion()" id="enviar" value="enviar"></input>
            </form>
    </body>

<html>

Don't know if it's the right way of doing it, but it solved my needs.

40,692

Author by

Oscar Swanros

I’m a self-taught iOS Developer with a passion for education. I currently live in Colima, Mexico, and for the past few years I’ve been working remotely both as a full time employee and contractor for different, mainly US-based companies. One of my main interests when building an iOS application is making sure the application can scale — that involves paying close attention to architectural decisions and technology choices. I’m also convinced that great design is not only what the user sees when they open the application, but also involves how the product is built and how it will evolve, that’s why I like to get really involved on any app I work on, so I can provide a robust framework in which new features can be built upon.

Updated on October 28, 2020

Comments

Oscar Swanros over 3 years

I'm learning Node.js.

I have this in my server:

var http = require("http");
var url = require("url");

http.createServer(function(request, response){
    response.writeHead(200, {"Content-Type":"text/plain"});
    var params = url.parse(request.url,true).query;

    console.log(params);

    var a = params.number1;
    var b = params.number2;

    var numA = new Number(a);
    var numB = new Number(b);

    var numOutput = new Number(numA + numB).toFixed(0);

    response.write(numOutput);
    response.end();
}).listen(10000);

An URL like this: localhost:10000/?number1=50000&number2=1 echoes 50001 on my browser, so it works.

Without using Express, I need to send those 2 params through a form using HTML.

How can this be achieved?

josh3736 over 10 years

There's zero reason to use JavaScript in the browser like this. Change it to <form action="/" method="get"> and <input type="submit" value="enviar"> and you're done.