Let's assume the module I am requiring has no dependencies. For example, a json file, or a webpack compiled file.
Is there a built in method (or an npm package) that allows you to resolve live instances of files in node?
For example:
foo.js
module.exports = function() {
return 'test!';
}
implementation.js
var liveFoo = require("live-monitor")("foo");
console.log(liveFoo.instance()); // this will auto update when saving foo.js.
I'd imagine this hypothetical node module live-monitor would internally use fs.watch to update the instance export as the file foo.js is changed.
So, anything built in to node? Any package out there that does this already?
Related
I have a script that does some analysis on my source files and a part of that analysis is to require the file. Some of the files are in JSX format however and node does not understand this by default.
Is it possible to make it so that a file that looks like this:
function MyModule () {
return <div>hello</div>
}
module.exports = MyModule
is possible to require through require('./my-module')?
Use JSX as a template engine in Node
NPM Package : https://www.npmjs.com/package/jsx-node
To be able to simply require .jsx files, you need to tell Node what to do with them. Running the following code makes you able to require('./SomeFile.jsx'):
require('jsx-node').install({
replace: {
preact: 'jsx-node',
}
});
Warning:
This module is still in a very early phase. Any production use should be approached with caution.
For more Detail visit Link.
I am using node v0.12.5 with nwjs and I have defined my own custom module inside of my project so that I can modularise my project (obviously).
I am trying to call my module from another module in my project but every time I attempt to require it I get the error could not find module 'uploader'.
My uploader module is currently very simple and looks like:
function ping_server(dns, cb) {
require('dns').lookup(dns, function(err) {
if (err && err.code == "ENOTFOUND") {
cb(false);
} else {
cb(true);
}
})
}
function upload_files()
{
}
module.exports.ping_server = ping_server;
module.exports.upload_files = upload_files;
With the idea that it will be used to recursively push files to a requested server if it can be pinged when the test device has internet connection.
I believe I have exported the methods correctly here using the module.exports syntax, I then try to include this module in my test.js file by using:
var uploader = require('uploader');
I also tried
var uploader = require('uploader.js');
But I believe node will automatically look for uploader.js if uploader is specified.
The file hierarchy for my app is as follows:
package.json
public
|-> lib
|-> test.js
|-> uploader.js
|-> css
|-> img
The only thing I am thinking, is that I heard node will try and source the node_modules folder which is to be included at the root directory of the application, could this be what is causing node not to find it? If not, why can node not see my file from test.js given they exist in the same directory?
UPDATE Sorry for the confusion, I have also tried using require('./uploader') and I am still getting the error: Uncaught Error: Cannot find module './uploader'.
UPDATE 2 I am normally completely against using images to convey code problems on SO, but I think this will significantly help the question:
It's clear here that test.js and uploader.js reside in the same location
When you don't pass a path (relative or absolute) to require(), it does a module lookup for the name passed in.
Change your require('uploader') to require('./uploader') or require(__dirname + '/uploader').
To load a local module (ie not one from node_modules) you need to prefix the path with ./. https://nodejs.org/api/modules.html#modules_modules
So in your case it would be var uploader = require('./uploader');
This problem stemmed from using Node Webkit instead of straight Node, as stated in their documentation all modules will be source from a node_modules directory at the root of the project.
Any internal non C++ libraries should be placed in the node_modules directory in order for Node webkit to find them.
Therefore to fix, I simply added a node_modules directory at the root of my project (outside of app and public) and placed the uploader.js file inside of there. Now when I call require('uploader') it works as expected.
If you're developing on a mac, check your file system case sensitivity. It could be that the required filename is capitalized wrong.
I'm using Gulp and Browserify to package my Javascript into 2 separate bundles: application.js and vendor.js.
How do I bundle the vendor package if my vendor libraries are installed with Bower?
In my gulpfile, I'm using the following modules:
var gulp = require("gulp");
var browserify = require("browserify");
var debowerify = require("debowerify");
var source = require("vinyl-source-stream");
Assuming that I have only the Phaser framework installed with bower (for this example), my Gulp task to create the application package looks like this:
gulp.task("scripts-app", function () {
browserify("./app/javascripts/index.js")
.external("phaser")
.pipe(source("application.js"))
.pipe(gulp.dest("./tmp/assets"));
});
Meanwhile, the vendor task looks like this:
gulp.task("scripts-vendor", function () {
browserify()
.transform(debowerify)
.require("phaser")
.pipe(source("vendor.js"))
.pipe(gulp.dest("./tmp/assets"));
});
When I run this Gulp task, I get an error that states Error: Cannot find module 'phaser' from and then all the directories it search through (none of which are the bower_components directory).
Any ideas about how to package these up successfully are greatly appreciated. Thanks!
Answered my own question:
When using require in the Gulp task, you need to supply a path to a file, not just a name.
gulp.task("scripts-vendor", function () {
browserify()
.transform(debowerify)
.require("./bower_components/phaser/phaser.js")
.pipe(source("vendor.js"))
.pipe(gulp.dest("./tmp/assets"));
});
Notice that require("phaser") became require("./bower_components/phaser/phaser.js").
Doing this works, although the bundle takes forever to build (around 20 seconds). You're probably better of just loading giant libraries/frameworks directly into your app through a <script> tag and then using Browserify Shim.
This let's you require() (in the NodeJS/Browserify sense) global variables (documentation).
Seems like you figured out how to require the bower file. Hopefully you'll only have to bundle it once initially, and not every build. Including the library via a script tag isn't a bad idea. Another technique I'm using is to use scriptjs (a polyfill would work too), to async load whatever vender libraries I need, but make sure to include any/all require's after the script loads. For example, your index.js could be like:
$script.('/assets/vendor', function() {
var phaser = require('phaser');
//rest of code
});
It's especially nice for loading cdn files or having the ability to defer loading certain libraries that aren't necessarily used in the core app by every user, or loading libraries after client-side routing.
is library versioning is supported in nodeJS?
i have folder like package/version/1.0/
and files under this path
test1.js
test2.js
script.js
//access the folder package of version 1.1
var lib = require('require-all')(__dirname + '/package/version/1.0');
test1.js
========
function sum()
{ a+b ;}
exports.sum = sum;
test2.js
========
function sub()
{ a-b ;}
exports.sub = sub;
in script.js file, can require the package/version/1.1 folder. but how can i access the function sum() and sub() in my script file? and is library versioning supported in nodeJS? is the above code is a sort of library versioning ?
First of all, i haven't seen versions of libraries in one package, most common way is to release new versions of packages and upload them online, defining the required version in a package.json dependencies , npm will take care of download & install
If you want to deprecate a certain version of your library online there is npm deprecate which is the right command for that job.
When you create new npm package you can define a main script which will handle the loading of all files inside the package.
Usually its called index.js or main.js and it will be used when someone calls require('<library>');
So you can try the following to achieve the "versioning"
index.js
var fs=require('fs');
var path=require('path');
var _packageJSON=require(__dirname+'/package.json');
var defaultVersion=_packageJSON.version;
module.exports=function(whichVersion){
whichVersion=whichVersion||defaultVersion;
fs.exists(whichVersion,function(_exists){
if(_exists==null){
throw new Error('Unable to load version : '+whichVersion+' : '+_packageJSON.name);
}else{
// require , 1.0/index.js
require(path.join(whichVersion,'index.js'));
}
}
}
and any script that has that package as dependency it can load it by simply calling
require("<library name>")(<version>) ex.
require("mylib")("1.0")
under each version inside the package, you can have index.js which loads/exports variables and functions properly.
The final structure should look like
my npm package main module
index.js file
versions directory
1.0/index.js file
util.js
fn.js
var.js
2.0/index.js file
util.js
fn.js
var.js
Hope it helps.
I am new with Nodejs. I want to export from file1.js file to file2.js.
file1.js is located in root-directory and file2.js is in some sub-directory. When I am calling it as require('/file1') in file2.js its saying like Uncaught Error: Module name "/file1" has not been loaded yet for context: _. Use require([]). Any help? Sorry if this is silly, but I am new.
var Logger = require('./logger');
Requires the module you have written, in a file called logger.js stored in the same directory your code was launched from.(not necessarily the same directory your code is stored in).
var someOtherModule = require('../../someOtherModule');
Requires someOtherModule.js file two directories back from where the node process is launched.
var someOtherModule = require('./subDir/someOtherModule');
Requires someOtherModule.js file, sotred in subDir. subDir is a directory located at the level of where the node process was launched.
var awssum = require('awssum');
Requires a module installed via NPM, in the node_modules directory from which the process was launched, or any globally installed node modules. For versioning, the node_modules directory takes precedence.