How to show all globally installed NPM packages

In this post, I want to show you how to list all installed NPM packages.
Type this command:

npm ls
npm list
npm la
npm ll

it will list all packages in current folder but it is locally not in globally. To do this we need to add option -g so it will list all with sub tree of packages.

npm list -g

On the other hand, if you can show only top level by add --depth=0

npm list -g --depth=0

How to upload file( only image) with nodeJs

Objective: uploading only image which we filters such as 'png', 'jpg' or 'jpeg' file with customized file name. Here are source code github

We use expressjs framework with multer middleware for handling file upload

Multer is a node.js middleware for handling multipart/form-data, which is primarily used for uploading files. It is written on top of busboy for maximum efficiency.

NOTE: Multer will not process any form which is not multipart (multipart/form-data). 

Implementation
+ View file: add enctype="multipart/form-data"

<form action="/" method="post" enctype="multipart/form-data">
    <input type="file" name="imageFile">
    <input type="submit">
</form>

+ Create function for filtering file extension.

function fileFilter(req, file, cb){
    var extensions = ['png','jpg','jpeg'];
    var bool = false;
    var extensionFile = getExtension(file);
    for(var i=0; i<extensions.length; i++){
        if(extensionFile == extensions[i]){
            cb(null, true);
            bool = true;
        }
    }
    if(!bool) cb(new Error("We support only 'png', 'jpg', jpeg."));
}

function getExtension(file){
    return file.originalname.substr(file.originalname.lastIndexOf(".")+1, file.originalname.length);
}

Throw Error 

+ Define upload directory to be store uploaded file.

var storage = multer.diskStorage({
    destination: function (req, file, cb) {
        cb(null, __dirname + '/uploads')
    },
    filename: function (req, file, cb) {
        cb(null, file.fieldname + '-' + Date.now() + "." + getExtension(file));
    }
});

var upload = multer({ storage: storage, fileFilter: fileFilter });

+ use middleware to upload url

app.use('/',upload.single('imageFile'), index);

Source Code: download here
Reference: https://www.npmjs.com/package/multer

Generate project expressjs

Overview: Expressjs is one of the most popular web framework which is build on top of nodejs. It is a minimal framework for creating server side or restful APIs (application programming interfaces).

Objective: Create project expressjs using express-generator

Quick Start:
First of all, you need to install express-generator

npm install -g express-generator

After installed let create the app by using key word express:

express --view<engine> project-name

Note: view <engine> support (ejs|hbs|hjs|jade|pug|twig|vash) (defaults to jade)

Install dependencies and running project by default app run at http://localhost:3000

npm install
npm start

Here are Command Line Options

-h, --help          output usage information
    --version       output the version number
-e, --ejs           add ejs engine support
    --hbs           add handlebars engine support
    --pug           add pug engine support
-H, --hogan         add hogan.js engine support
-v, --view          add view  support (ejs|hbs|hjs|jade|pug|twig|vash) 
      (defaults to jade)
-c, --css           add stylesheet  support (less|stylus|compass|sass) 
      (defaults to plain css)
    --git           add .gitignore
-f, --force         force on non-empty directory

Easy Step: Auto Start NodeJs Server on Startup Windows

Overview: Generally, when we start server nodejs we use command node server.js or node bin/www for express framework. Restarting or start computer you need to run that command line again. In the article I will show you some tips to solve to issue.

Objective: When computer startup service node js is automatically started.

• Forever: make process run continuously and automatically restart when it exits unexpectedly.

Implementation: 

• Install forever in globally 

  npm install -g forever

• Create VbScript for executing project: I put it in root of project directory   

  Set WshShell = WScript.CreateObject("WScript.Shell")
  Return = WshShell.Run("cmd.exe /C forever start bin/www", 1, true)

• Startup folder
  You can link VBscript file(shortcut) to startup folder

• Restart computer 

Logging NodeJs with Winston

Objective: We create log file (Daily log file: info.log.2016-08-22)  Source code github

• Show log in Console and in File

Implementation

1. Create project using Express generator 

   
   express -e winstonjs-console-and-file
   
   

   Note: if you don't have express generator you can install via command line

   
   npm install express-generator -g
   
   

2. Install Winston 

   
   npm install --save winston@0.8.3
   
   

3. Open app.js write some code

   
   var FileStreamRotator = require('file-stream-rotator');
   var fs = require('fs');
   
   var logDirectory = __dirname + '/logs'
   
   // ensure log directory exists
   fs.existsSync(logDirectory) || fs.mkdirSync(logDirectory);
   
   // create a rotating write stream
   var accessLogStream = FileStreamRotator.getStream({
     filename: logDirectory + '/access-%DATE%.log',
     frequency: 'daily',
     verbose: false,
     date_format: 'YYYY-MM-DD'
   });
   
   app.use(morgan('combined', {stream: accessLogStream}));
   
   

4. Create folder logger then file index.js 

   
   var winston = require("winston");
   
   if(process.env == 'production') {
       winston.level = 'info';
   }
   else {
       winston.level = 'debug';
   }
     
   winston.loggers.add('info', {
       console: {
          level: winston.level,
          colorize: true,
          label: 'category one'
       },
       file: {
         level: winston.level,      
         colorize: 'true',
         filename: __dirname + '/../logs/info/info.log',
         datePattern: '.yyyy-MM-dd',
         //maxsize: 20000,
         json: false
           
       },
       DailyRotateFile: {
           level: winston.level,
           colorize: 'true',
           filename: __dirname + '/../logs/info/info.log',
           datePattern: '.yyyy-MM-dd',
           //maxsize: 20000,
           json: false
       }
   });
   
   module.exports = winston.loggers.get('info');
   
   

5. How to use: call file /logger/index.js

   
   var logger = require("../logger");
   
   logger.info("This is logger.");
   
   

6. Result: It shows in Console and File

Download Source code github