Keynote: Quick Creation of Node.js Module

This is short note about fast creation, publishing & using Node.js module via using Command Line Interface.

• Use npm init to create package.json.
• Run npm install --save to install dependency and save it to package.json.

When the code in the foo package does require('bar'), it will be loaded either foo/node_modules/bar or from core modules if it was installed as a global module via nmp install -g command.

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Node modules creation with CLI

Just to refresh the memory, here is how how we create & use Node module:

Creating the Node module:

• Make a new folder mkdir <package>
• Create packaje.json by running npm init
• Create the file that will be loaded when your module is required. index.js by default.
• Publish your module to npm by using npm publish

Using the published package:

• Make a new directory outside of the project mkdir <dir> and cd into it
• Run npm install <package>
• Create a my.js file which requires the package and calls the method
• Run node my.js to invoke the script.

Bash

mkdir my-app
cd my-app
npm install simple-get-json --save
vi my.js
~
~    var getJSON = require('simple-get-json');
~    getJSON('http://samples.openweathermap.org/data/2.5/weather?q=London,uk&appid=b1b15e88fa797225412429c1c50c122a1', function(data){
~        console.log(data);
~    });
~    // press Esc :wq to save and quit from Vim
node my.js

Output:

JSON

{ coord: { lon: -0.13, lat: 51.51 },
  weather:
   [ { id: 300,
       main: 'Drizzle',
       description: 'light intensity drizzle',
       icon: '09d' } ],
  base: 'stations',
  main:
   { temp: 280.32,
     pressure: 1012,
     humidity: 81,
     temp_min: 279.15,
     temp_max: 281.15 },
  visibility: 10000,
  wind: { speed: 4.1, deg: 80 },
  clouds: { all: 90 },
  dt: 1485789600,
  sys:
   { type: 1,
     id: 5091,
     message: 0.0103,
     country: 'GB',
     sunrise: 1485762037,
     sunset: 1485794875 },
  id: 2643743,
  name: 'London',
  cod: 200 }

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see Also

• The easiest way to start your Local Webserver with Node.js
• Catch JS breakpoints in IDEA
• NPM package - simple-get-json
• Using Vim - Interactive Tutorial
• NPM CLI - init command
• NPM CLI - install command
• Node.js - Modules
• NPM Module Creation