joe-oli/basicServer101.js

## basicServer101.js
/* ============= basicServer101.js ============== */
/* shows
    - handling Body in a POST (or PUT) request;
    - two http-request handlers can be hooked up to the same event; both get called one after the other... (just experimenting... we could use one handler with if-then inside it)

USAGE:
at a cmd prompt enter:
    >node basicServer101

then at a Browser enter:
    http://localhost:8080/
*/

const http = require('http');

//create server...
const myServer = http.createServer(); //LHS is called an EventEmitter
//then hookup two request handlers in succession... BOTH WILL BE HIT on every request, but if-condition based on http-method decides if they will do anything...

//first-handler... for GET
myServer.on('request', function(req,res) { //add handler to EventEmitter
   const { method, url, headers} = req;
   //When a http-request hits the server, examine the URL and method, so that appropriate actions can be taken...

   if (method === 'GET') {
        console.log('========> GET handler at...' + new Date().toISOString())
       /*
        console.log("method:", method)
        console.log("url:", url)    //variation test: add a queryString to the Browser url. e.g. http://localhost:8080/?key1=fax&key2=off; THEN YOU SHOULD SEE url: /?key1=fax&key2=off
        console.log("headers.host:", headers.host)
        console.log("headers.user-agent:", headers["user-agent"]) //<============ due to hyphen - in propname, extract using Array[syntax] instead of Object.Prop)
        */

        res.writeHead(200, {'Content-Type' : 'text/html'});
        res.write('<h2>hello World!</h2>');
        res.write('<div>... from a basic node server:-)</div>');
        res.write('<p>&nbsp;</p>');

        // fields on page to post data back to server,,,
        res.write('<form method="POST" action="/">')
        res.write('<input type="text" name="txtfirstName" value="joe" />')
        res.write('<br />')
        res.write('<input type="text" name="txtlastName" value="oli" />')
        res.write('<p>&nbsp;</p>')
        res.write('<input type="submit" name="btnSubmit" />')
        res.write('</form>')
        res.end();

        /* serve following page...
        <html>
        <head></head>
        <body>
            <h2>hello World!</h2>
            <div>... from a basic node server:-)</div>
            <p>&nbsp;</p>
            <form method="POST" action="/">
                <input type="text" name="txtfirstName" value="joe" /><br>
                <input type="text" name="txtlastName" value="oli" />
                <p>&nbsp;</p>
                <input type="submit" name="btnSubmit" />
            </form>
        </body>
        </html>
        */
   }
});

//second-handler.. for POST
myServer.on('request', function(req,res) { //add handler to EventEmitter
    const { method, url, headers} = req;
    //When a http-request hits the server, examine the URL and method, so that appropriate actions can be taken...

   if (method == 'POST') {
        console.log('========> POST handler at...' + new Date().toISOString())

        let body = []; let bodyAsString = "";
            req.on('data', (chunk) => {
            body.push(chunk);
        }).on('end', () => {
            bodyAsString = Buffer.concat(body).toString();
            // at this point, `bodyAsString` has the entire request body stored in it as a string
            console.log(bodyAsString) //txtfirstName=joe&txtlastName=oli&btnSubmit=Submit

            //NOW serve a new page ...
            res.writeHead(200, {'Content-Type' : 'text/html'});
            res.write('<h3>you submitted:</h3>');

            //extract what was posted...
            let keyValArr = bodyAsString.split("&");
            keyValArr.map( (kvp, idx) => {
                let keyVal = kvp.split('=');

                res.write('<div>')
                res.write('<label style="color:green">'+keyVal[0]+':</label>')
                res.write('<span>'+keyVal[1]+'</span>')
                res.write('</div>')
            })

            res.write('<p>&nbsp;</p>');
            res.write('<a href="/">Go back</a>') //make a GET request using link

            //or ALT use js...
            res.write('<p>&nbsp;</p>');
            // res.write('<button type="button" onclick="alert(\'fax off\')">Go back</button>')
            res.write('<button type="button" onclick="window.location.href= \'/\'">Go back</button>')

            res.write('<p>&nbsp;</p>');
            res.end();
            /* serve following page...
            <html>
            <head></head>
            <body>
                <h3>you submitted:</h3>
                <div><label style="color:green">txtfirstName:</label><span>joe</span></div>
                <div><label style="color:green">txtlastName:</label><span>oli</span></div>
                <div><label style="color:green">btnSubmit:</label><span>Submit</span></div>
                <p>&nbsp;</p><a href="/">Go back</a>
                <p>&nbsp;</p><button type="button" onclick="window.location.href= '/'">Go back</button>
                <p>&nbsp;</p>
            </body>
            </html>
            */
        }).on('error', (err) => {
            console.error(err.stack); // This prints the error message and stack trace to `stderr`.
            //NB: it's important to be listening for error events on the stream, else the error will be thrown which may crash your Node.js program.
        });
    }

});

myServer.listen(8080, function() {
    console.log('nodejs server is listening on port 8080...');
})
	/* ============= basicServer101.js ============== */
	/* shows
	- handling Body in a POST (or PUT) request;
	- two http-request handlers can be hooked up to the same event; both get called one after the other... (just experimenting... we could use one handler with if-then inside it)

	USAGE:
	at a cmd prompt enter:
	>node basicServer101

	then at a Browser enter:
	http://localhost:8080/
	*/

	const http = require('http');

	//create server...
	const myServer = http.createServer(); //LHS is called an EventEmitter
	//then hookup two request handlers in succession... BOTH WILL BE HIT on every request, but if-condition based on http-method decides if they will do anything...

	//first-handler... for GET
	myServer.on('request', function(req,res) { //add handler to EventEmitter
	const { method, url, headers} = req;
	//When a http-request hits the server, examine the URL and method, so that appropriate actions can be taken...

	if (method === 'GET') {
	console.log('========> GET handler at...' + new Date().toISOString())
	/*
	console.log("method:", method)
	console.log("url:", url) //variation test: add a queryString to the Browser url. e.g. http://localhost:8080/?key1=fax&key2=off; THEN YOU SHOULD SEE url: /?key1=fax&key2=off
	console.log("headers.host:", headers.host)
	console.log("headers.user-agent:", headers["user-agent"]) //<============ due to hyphen - in propname, extract using Array[syntax] instead of Object.Prop)
	*/

	res.writeHead(200, {'Content-Type' : 'text/html'});
	res.write('<h2>hello World!</h2>');
	res.write('<div>... from a basic node server:-)</div>');
	res.write('<p> </p>');

	// fields on page to post data back to server,,,
	res.write('<form method="POST" action="/">')
	res.write('<input type="text" name="txtfirstName" value="joe" />')
	res.write('<br />')
	res.write('<input type="text" name="txtlastName" value="oli" />')
	res.write('<p> </p>')
	res.write('<input type="submit" name="btnSubmit" />')
	res.write('</form>')
	res.end();

	/* serve following page...
	<html>
	<head></head>
	<body>
	<h2>hello World!</h2>
	<div>... from a basic node server:-)</div>
	<p> </p>
	<form method="POST" action="/">
	<input type="text" name="txtfirstName" value="joe" /><br>
	<input type="text" name="txtlastName" value="oli" />
	<p> </p>
	<input type="submit" name="btnSubmit" />
	</form>
	</body>
	</html>
	*/
	}
	});

	//second-handler.. for POST
	myServer.on('request', function(req,res) { //add handler to EventEmitter
	const { method, url, headers} = req;
	//When a http-request hits the server, examine the URL and method, so that appropriate actions can be taken...

	if (method == 'POST') {
	console.log('========> POST handler at...' + new Date().toISOString())

	let body = []; let bodyAsString = "";
	req.on('data', (chunk) => {
	body.push(chunk);
	}).on('end', () => {
	bodyAsString = Buffer.concat(body).toString();
	// at this point, `bodyAsString` has the entire request body stored in it as a string
	console.log(bodyAsString) //txtfirstName=joe&txtlastName=oli&btnSubmit=Submit

	//NOW serve a new page ...
	res.writeHead(200, {'Content-Type' : 'text/html'});
	res.write('<h3>you submitted:</h3>');

	//extract what was posted...
	let keyValArr = bodyAsString.split("&");
	keyValArr.map( (kvp, idx) => {
	let keyVal = kvp.split('=');

	res.write('<div>')
	res.write('<label style="color:green">'+keyVal[0]+':</label>')
	res.write('<span>'+keyVal[1]+'</span>')
	res.write('</div>')
	})

	res.write('<p> </p>');
	res.write('<a href="/">Go back</a>') //make a GET request using link

	//or ALT use js...
	res.write('<p> </p>');
	// res.write('<button type="button" onclick="alert(\'fax off\')">Go back</button>')
	res.write('<button type="button" onclick="window.location.href= \'/\'">Go back</button>')

	res.write('<p> </p>');
	res.end();
	/* serve following page...
	<html>
	<head></head>
	<body>
	<h3>you submitted:</h3>
	<div><label style="color:green">txtfirstName:</label><span>joe</span></div>
	<div><label style="color:green">txtlastName:</label><span>oli</span></div>
	<div><label style="color:green">btnSubmit:</label><span>Submit</span></div>
	<p> </p><a href="/">Go back</a>
	<p> </p><button type="button" onclick="window.location.href= '/'">Go back</button>
	<p> </p>
	</body>
	</html>
	*/
	}).on('error', (err) => {
	console.error(err.stack); // This prints the error message and stack trace to `stderr`.
	//NB: it's important to be listening for error events on the stream, else the error will be thrown which may crash your Node.js program.
	});
	}

	});

	myServer.listen(8080, function() {
	console.log('nodejs server is listening on port 8080...');
	})