Persistent variables in nodeJS

Question

Persistent variables in nodeJS

I am writing a node app that needs to remember data across connection iterations of the createServer() callback. Is there a simple way that doesn't involve databases or file r/w? I've sofar attempted creating objects in the respective modules and even main script while passing them into various response handlers, however for every connection they are flushed.

What I mean by that:

require('http').createServer(function(req,res){
        route(req,res,object);
}).listen(cp=80);

object={variable:0}

function route(req,res,object){
    res.end();
    console.log(object.variable);
    object.variable=Math.floor(Math.random()*100);
}

console.log is unsurprisingly throws 0 every connection in this case. Is there any way to create global variables, not in the sense of being available across modules, but persistent unlike var's?

javascript
node.js

Answer 1

Each module in Node has its own scope, so no, var Foo; does not create a global variable Foo. Use global object from inside the modules.

UPDATE:

require('http').createServer(function(req,res){
        route(req,res,object);
}).listen(cp=8080);

object={variable:0}
global.foo = 'Bar'; // I added this

function route(req,res,object){
    res.end();
    console.log(object.variable);
    console.log("foo = %s", global.foo); // I added this too
    object.variable=Math.floor(Math.random()*100);
}

And it logs "foo = Bar" as expected as well.

Answer 2

It works correctly for me (after applying Peter's fix). Module-scope variables are indeed persistent.