I'm using a customized version of node-clim, but I want to put away all the customization code in a module of its own and require() it in my main app. But I can't seem to do that..
This code works
var util = require('util');
var clim = require('clim')
clim.logWrite = function(level, prefixes, msg) {
...
customizing code
...
process.stderr.write(...);
};
var console = clim();
console.log('hey'); // works
But in trying to put the above in a separate file clim.js and exporting the console object...
module.export = console;
and require()ing it in my main app doesn't work..
var console = require('./clim');
console.log('hey');
// ^ TypeError: Object #<Object> has no method 'log'
What am I doing wrong?
Change
module.export = console;
to
module.exports = console;
Related
Hi,
I made an app for node.js so my app.js looks like this:
global.fs = require("fs");
global.vm = require('vm');
var includefile = function(path) {
var code = fs.readFileSync(path);
vm.runInThisContext(code, path);
}.bind(this);
includefile("variables.js");
as for variables.js I have this:
global.app = require("express")();
but when I start the app I get this error:
require is not defined at variables.js
why is it that requires loads fine if executed from app.js but not from an external file?
Thank you.
I'm a little confused, is variables.js just another source file in your project? All you should need to do is require the file in like you've done at the top. As an example for variables.js:
const Variables = {
fs: "some_value"
};
module.exports = Variables;
And for app.js
const { Variables } = require("./variables.js");
const fs = Variables.fs;
Executing console.log(fs); in app.js will print "some_value". Same can be done with functions.
If variables.js is part of your project code, you should use the answer of M. Gercz.
If it's not part of your project code and you want to get some information from it, you could use a json file:
app.js
const variables = require('variables.json');
console.log(variables.whatever);
variables.json
{ whatever: "valuable information" }
If it's not certain, that variables.json is preset, you can do a check using fs.existsSync;
Notice: As jfriend00 commented, using global is not recommended.
I am new to NodeJS programming so I was trying make simple custom module by extending one module to another which prints in console log.
ExtendMod.js
var exports = module.exports = {};
exports.tutorial = function() {
console.log("N Tutotial");
}
app.js
var Tutor=require('./ExtendMod.js');
exports.NodeTutorial = function() {
console.log("Node Tutorial")
function pTutor() {
var PTutor=Tutor
PTutor.tutorial;
}
}
console.log(require('./thirdNode.js').NodeTutorial());
I have extended ExtendMod.js in app.js.
Question: Why an empty braces after exports when we create my first module and also in app.js we didn't take exports as a variable is it global?
My output :
Node Tutorial
N Tutorial
Undefined
What is this undefined?
I work on a server in node.js, and i'm quite new to the concept.
I'm using socket.io to communicate with clients
I have many modules in my server and i try to send a function declared in a module to my main. I don't want to use exports.plugin=plugin because I try to work with the observer pattern.
I tried :
In main.js:
//Modules NPM
var express = require('express');
var observer = require('node-observer');
//Extensions JS
var mymodule = require('./mymodule');
var plugin = require('./plugin');
//Initialisation
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io').listen(server);
...
socket.on('message', function (var1, var2) { //Come from client
socket.var1=var1;
socket.var2=var2;
observer.send(this, "Message", "varSpecification");
});
In plugin.js :
//Modules NPM
var express = require('express');
var observer = require('node-observer');
//Extensions JS
var mymodule = require('./mymodule');
var main = require("./main");
...
observer.subscribe(this, "Message", function(who, data) {
var functionToSend= new Function ("varA", "varB" ,"mymodule.function(varA, varB); socket.emit('messageOK');"); //I can't create a real function because i don't use socket.io in the module Plugin
observer.send(this, "Response", functionToSend); });
Back to the main:
observer.subscribe(this, "Response", function(who, functionReceived) {
functionReceived(socket.var1, socket.var2); //Doesn't work
});
The problem is that when I execute the function in main.js, it doesn't find mymodule and can't execute the function associated.
(ReferenceError : mymodule is not defined)
When i execute the function directly in the main.js, it works.
observer.subscribe(this, "Response", function(who, functionReceived) {
mymodule.function(socket.var1, socket.var2); //Works
});
So I guess it's a problem with the object that I send
I will be more than grateful if you can help me!
EDIT : After other tests I found the source of the problem :
var mymodule = require('./mymodule');
...
mymodule.function(a, b); //works
var functionTest= new Function('mymodule.function(a, b)');
functionTest(); //Doesn't work (mymodule is not defined)
I still want to use the second option for my project but don't know how
I used the function constructor, and i didn't know that the function is declared in the global scope.
So i had to write this to make it work :
var functionTest= new Function('mymodule', 'a', 'b','mymodule.function(a, b)');
functionTest(mymodule,a,b);
I had to pass mymodule, a and b in parameter
I'm new to nodejs. I have the following files and code:
// file: myfunc.js
function myfunc() { return "myfunc()"; }
exports = myfunc;
and
// file: index.js
var mf = require("./myfunc");
var mfunc = mf();
console.log(mfunc);
When I run node index.js from command line, I get the error
var mfunc = mf()
^
TypeError: Object is not a function
Why do I get this error? I saw someone else's code which I paste below and I tried to follow the same approach of trying to get require() to return a function instead of an object.
// file: index.js from another app
var express = require('express');
var app = express();
How come require('express') can return a function but require('./myfunc') can't return a function?
It should be...
module.exports = myfunc;
... instead. Quoting the doc:
If you want the root of your module's export to be a function (such as
a constructor) or if you want to export a complete object in one
assignment instead of building it one property at a time, assign it to
module.exports instead of exports.
I'm having an issue utilizing an external jQuery file with node. I have several functions that I need to run but it isn't working. I created a simple function to test but the error message I keep getting is TypeError: Object # has no method 'alert_helloworld'. Here are my two files:
example.js
var jsdom = require('jsdom');
var templateparser = require('./templateparser.js');
var test = templateparser.alert_helloworld();
templateparser.js
function alert_helloworld(){
console.log("Hello World");
return false;
}
HELP!!!!
You need to use the exports object in templateparser.js:
exports = exports || {};
exports.alert_helloworld = function(){
console.log("Hello World");
return false;
}
Take a look at the modules docs: http://nodejs.org/docs/latest/api/modules.html
module.exports.alert_helloworld = function alert_helloworld(){
console.log("Hello World");
return false;
};
It's important you actually export the functions you need. node.js modules by default are wrapped in their own isolated module scope.