Running php code inside a node.js socket server script

Question

I am running a normal TCP socket in javascript and uses node to execute. Before I send a response back to the client, I want to validate the data with some some php (mysql) code. How can I execute this code inside this javascript file? All similar questions in STACKOVERFLOW asks about this code in HTML. (which is okay and I understand that part), But this is a normal javascript file (executed in node). The javascript code is below and I've marked the validation function call.

var net = require('net');

var HOST = '192.168.0.6';
var PORT = 8765;

net.createServer(function(sock) {

    console.log('CONNECTED: ' + sock.remoteAddress +':'+ sock.remotePort);

    sock.on('data', function(data) {
        var output;
        var validScan;

        //This is the function call to a php file
        **validScan = validateScanTag(data);**

        console.log('DATA ' + sock.remoteAddress + ': ' + data);
        sock.write(validScan);

    });

    // Closing this instance of socket
    sock.on('close', function(data) {
        console.log('CLOSED: ' + sock.remoteAddress +' '+ sock.remotePort);
    });

}).listen(PORT, HOST);

console.log('Server listening on ' + HOST +':'+ PORT);

The validateScanTag executes a line lke :

$.post('getperiod.php', {hours:hrs, minutes:mins, seconds:secs, ddd:day},

But this dont work. How can I call this 'geteriod.php' file from a javascript file?

Answer 1

I'm pretty sure the problem itself is well worth rethinking (for example, port your mysql code from php to node) but here is my solution:

var net = require('net');
var PORT = 8765;
var Lazy=require('lazy');
var spawn = require('child_process').spawn;

// php code runs as a server in external process

var validator = spawn('php', ['validator.php']);

net.createServer(function(sock) {

    console.log('CONNECTED: ' + sock.remoteAddress +':'+ sock.remotePort);

    // on 'data' handler is not enough to read input line by line
    // you need to buffer data, use some kind of state machine or one of available stream parsers. I use lazy here: npm install lazy

    // write each line to php validation code
    new Lazy(sock).lines.forEach(function(line) {
        console.log('DATA ' + sock.remoteAddress + ': ' + line.toString());
        validator.stdin.write(line);
        validator.stdin.write('\n');
    });

    // read validation result line by line from validator process
    new Lazy(validator.stdout).lines.forEach(function(line) {
        console.log('Validation result:' + line.toString()) // line is Buffer object here, hence toString
    });

    validator.stdout.pipe(process.stdout);

    // Closing this instance of socket
    sock.on('close', function() {
        console.log('CLOSED');
    });

}).listen(PORT);

validator.php should read from stdin and write to stdout

<?

function validatescanTag($l) {
    // put your validation code here
    return $l . '!!!!';
}

$stdin = fopen('php://stdin', 'r');

do {
  $line = fgets($stdin);
  print validateScanTag($line);
} while(1);

?>

Another option is to use fastcgi protocol to communicate node <-> php or dnode rpc. Or just use http and run php from nginx/apache (or even node-php)

Answer 2

An approach to give a more generic answer for clarification and "getting you on the boots":

As far as I understand you're trying to run your php script using a http post request invoked by the node.js server.

You probably first have to become aware of the fact that running server-side JavaScript normally has different motivation and possibilities as well as impacts on your architecture than running JS inside a browser - at least in a classical "jQuery sense".

As stated in your comment you expect jQuery to work seamlessly within server-side node.js. That doesn't work as the comment-posted ReferenceError: $ is not defined shows you. There is no server-side jQuery available in your node.js stack working out-of-the-box (possibilities of using jQuery server-side should be discussed separately and is another subject).

Nevertheless you're obviously looking for a way to re-use your PHP script which already handles your mysql data connection and handling by utilizing it server-side. Doing this using http there are possibilites like shown in this stackoverflow post or in the http.request section of the node.js documentation. If your php script resides on the same server (or better runtime environment) as your node.js is running you may also directly execute the php script it by spawning it as a child process with the php standalone (command line) utility.

Last but not least: Yes, there are some ways (npm modules, ORM layers) for connecting mysql directly with your node.js app. But that's another complex subject and is discussed at other places.

I hope that helped in a way to avoid mixing up things that shouldn't be mixed up.

Answer 3

There is a PHP extension embedding Chrome's V8 engine in PHP.