Deprecation notice 🚨

I strongly suggest you to move to log-update that came out a little after I first wrote this module. It's really complete and making the switch should be really easy. Also, PhantomJS 2.1 has finally came out solving the problems I was trying to work around with this module.

log-output

Persist log messages on the command line.

_{Formerly write.js.}

Install

$ npm install --save log-output

Usage

var logOutput = require('log-output');
var frames = 'lorem ipsum dolor sit'.split(' ');
var frame = 0;

setInterval(function() {
  frame = frames[frame++ % frames.length];
  logOutput(frames[frame]);
}, 1000);

API

logOutput(message)

message

Required
Type: string

Output message.

logOutput.stream()

Type: Stream object

Specify a stream to output.

logOutput.adapter()

Specify a writable stream interface, which is essentially an adapter.

The interface must implement the following API:

• resetLine() - Reset current output line
• newLine() - Add a new output line
• resetCursor([position]) - Reset cursor position (position defaults to 0)
• output(message) - Output message

Official adapters are:

• log-output-node - Node.js adapter. This is the default adapter.
• log-output-phantom - PhantomJS adapter.

You can specify your own:

var logOutput = require('log-output');
var customAdapter = function() {
  // Assuming you have a custom stream with a non-standard interface
  var stream = require('custom-stream');

  return {
    resetLine: function() {},
    newLine: function() {},
    resetCursor: function(position) {},
    output: function() {}
  }
};

logOutput.adapter(customAdapter);
logOutput('yay'); // yay

logOutput.clear()

Shortcut to empty current output.

logOutput.done()

Shortcut to output a new line.

Motivation

I wanted to visually persist log messages on the command line. Turns out this can be a bit tricky, that's why I have created this module.

Thoughts on log-update

log-update is essentially the same idea of log-output but it was released later and has no support for stream adapters.
Adapters support was one of the reasons I've created this module in the first place. I needed a way to persist the log messages within a PhantomJS instance.

License

MIT © Rafael Rinaldi