status-bar

A status bar for file transfers

Example

var path = require('path');
var http = require('http');
var statusBar = require('status-bar');
 
var url = 'http://nodejs.org/dist/latest/node.exe';
var bar;
 
http.get(url, function (res) {
  bar = statusBar.create({ total: res.headers['content-length'] })
      .on('render', function (stats) {
        process.stdout.write(
            path.basename(url) + ' ' +
            this.format.storage(stats.currentSize) + ' ' +
            this.format.speed(stats.speed) + ' ' +
            this.format.time(stats.elapsedTime) + ' ' +
            this.format.time(stats.remainingTime) + ' [' +
            this.format.progressBar(stats.percentage) + '] ' +
            this.format.percentage(stats.percentage));
        process.stdout.cursorTo(0);
      });
  
  res.pipe(bar);
}).on('error', function (err) {
  if (bar) bar.cancel();
  console.error(err);
});
 
/*
It will print something like this:
 
node.exe    2.8 MiB  617.5K/s 00:06 00:07 [############············]  51%
*/

Why you should try this module

• It doesn't print anything, it just calculates and returns raw data and provides default formatting functions.
• The status bar can be displayed wherever you want, it is simply a string, so you can render it in the console, in HTML (probably with your own progress bar) via websockets or NW.js, etc.
• You decide how to format and arrange the elements. The default formatting functions have a fixed length, so you can format the status bar very easily.
• It is very easy to use. Just pipe() things to it!

Render function examples

• pacman from Arch Linux:

  a-file                  21.8 MiB   67.9M/s 00:03 [#####···················]  22%
  

  var statusBar = require('status-bar');
   
  var formatFilename = function (filename) {
    //80 - 59
    var filenameMaxLength = 21;
    if (filename.length > filenameMaxLength) {
      filename = filename.slice(0, filenameMaxLength - 3) + '...';
    } else {
      var remaining = filenameMaxLength - filename.length;
      while (remaining--) {
        filename += ' ';
      }
    }
    return filename;
  };
   
  filename = formatFilename(filename);
   
  var bar = statusBar.create({ total: ... })
      .on('render', function (stats) {
        process.stdout.write(filename + ' ' + 
            this.format.storage(stats.currentSize) + ' ' +
            this.format.speed(stats.speed) + ' ' +
            this.format.time(stats.remainingTime) + ' [' +
            this.format.progressBar(stats.percentage) + '] ' +
            this.format.percentage(stats.percentage));
        process.stdout.cursorTo(0);
      });
      
  readableStream.pipe(bar);

• git clone:

  Receiving objects: 18% (56655992/311833402), 54.0 MiB | 26.7M/s
  

  var statusBar = require('status-bar');
   
  var bar = statusBar.create({ total: ...})
      .on('render', function (stats) {
        process.stdout.write('Receiving objects: ' +
            this.format.percentage(stats.percentage).trim() +
            ' (' + stats.currentSize + '/' + stats.totalSize + '), ' +
            this.format.storage(stats.currentSize).trim() + ' | ' +
            this.format.speed(stats.speed).trim());
        process.stdout.cursorTo(0);
      });
   
  readableStream.pipe(bar);

Functions

• module.create(options) : StatusBar

Objects

• StatusBar

---

module.create(options) : StatusBar

Returns a new StatusBar instance.

Options:

• frequency - Number
  The rendering frequency in milliseconds. It must be a positive value. Default is 200.
• progressBarComplete - String
  The character that shows completion progress. Default is #.
• progressBarIncomplete - String
  The character that shows the remaining progress. Default is ·.
• progressBarLength - Number
  The length of the progress bar. Default is 24.
• total - Number
  The total size of the file. This option is required.

---

StatusBar

The StatusBar object inherits from a writable stream.

Events

• finish
• hangup
• render

Methods

• StatusBar#cancel() : undefined

Properties

• StatusBar#format : Formatter

---

finish

Arguments: none.

Emitted when the transfer finishes.

hangup

Arguments: none.

Emitted when the transfer hangs up (3 seconds without receiving data). Can be emitted multiple times.

render

Arguments: stats.

Emitted when the status bar needs to be rendered. All the properties of the stats object contain raw data so you need to format them. You can use the default formatting functions.

Stats:

• currentSize - Number
  The current size in bytes.
• remainingSize - Number
  The remaining size in bytes.
• totalSize - Number
  The total size in bytes.
• percentage - Number
  The progress percentage (current/total size). A number between 0 and 1.
• speed - Number
  The current speed in bytes per second.
• elapsedTime - Number
  The elapsed time in seconds.
• remainingTime - Number
  The estimated remaining time in seconds. If the remaining time cannot be estimated because the status bar needs at least 2 chunks of data or because the transfer it's hung up, it returns undefined.

---

StatusBar#cancel() : undefined

When you need to cancel the rendering of the status bar because the transfer has been aborted due to an error or any other reason, call to this function to clear the internal timers.

---

StatusBar#format : Formatter

Returns a Formatter instance.

---

Formatter

Methods

• Formatter#percentage(percentage) : String
• Formatter#progressBar(percentage) : String
• Formatter#speed(bytesPerSecond) : String
• Formatter#storage(bytes) : String
• Formatter#time(seconds) : String

---

Formatter#percentage(percentage) : String

The percentage must be a number between 0 and 1. Result string length: 4.

console.log(this.format.percentage(0.5));
/*
50%
 */

---

Formatter#progressBar(percentage) : String

The percentage must be a number between 0 and 1. Result string length: the length configured with the option progressBarLength.

console.log(this.format.progressBar(0.06));
/*
#·······················
 */

---

Formatter#speed(bytesPerSecond[, decimals]) : String

By default it shows 1 decimal. Result string length: 8 + #decimals.

console.log(this.format.speed(30098226));
/*
  30.1M/s
 */

---

Formatter#storage(bytes[, decimals]) : String

By default it shows 1 decimal. Result string length: 9 + #decimals.

console.log(this.format.storage(38546744));
/*
  36.8 MiB
 */

---

Formatter#time(seconds) : String

Result string length: 5 (min:sec). If seconds is undefined it prints --:--.

console.log(this.format.time(63));
/*
01:03
 */