Take fast screenshots with Phantom.js from Node.js

1-screenshot.js

/*
original : https://gist.github.com/BinaryMuse/2378993
Changes :
-Shares an instance of phantomJS for all requests instead of creating a new one for each
-Sends the created file as a response
-Uses good old JavaScript
-Coffee version below
*/

var phantom = require('phantom'),
_ = require('underscore'),//if you dont want underscore, do a foreach instead of _.each
phantomInstance = false,
phantomCallbacks = [];

console.log("Opening a new phantomJS instance");
phantom.create(function(ph) {
  console.log("PhantomJS loaded");
  phantomInstance = ph;
  _.each(phantomCallbacks, function(cb){
    cb();
  });
});

exports.takeSnapshot = function(folder, filename, url,  res) {

  var DEST_ROOT = "../../";
  var filepath = folder + "/" + filename;
  var previewPath = DEST_ROOT + filepath;

  function snapShot(){
    return phantomInstance.createPage(function(page) {
      page.set('viewportSize', {
        width: 640,
        height: 800
      });
      page.set('clipRect', {
        top: 0,
        left: 0,
        width: 640,
        height: 800
      });
      console.log("Opening " + url + " ...");
      return page.open(url, function(status) {
        console.log("Rendering screenshot ...");
        return setTimeout((function() {
          return page.render(previewPath, function() {
            page.close();
            setTimeout(function(){
                  res.sendfile(filepath, {root: __dirname+DEST_ROOT});
              }, 10);
          });
        }), 500);
      });
    });
  }
  if(phantomInstance){
    snapShot();
  }
  else{
    phantomCallbacks.push(snapShot);
  }
}

2-screenshot.coffee

#
#original : https://gist.github.com/BinaryMuse/2378993
#Changes :
#-Shares an instance of phantomJS for all requests instead of creating a new one for each
#-Sends the created file as a response
#
phantom = require("phantom")
_ = require("underscore") #if you dont want underscore, do a foreach instead of _.each
phantomInstance = false
phantomCallbacks = []
console.log "Opening a new phantomJS instance"
phantom.create (ph) ->
  console.log "PhantomJS loaded"
  phantomInstance = ph
  _.each phantomCallbacks, (cb) ->
    cb()
    return

  return

exports.takeSnapshot = (folder, filename, url, res) ->
  snapShot = ->
    phantomInstance.createPage (page) ->
      page.set "viewportSize",
        width: 640
        height: 800

      page.set "clipRect",
        top: 0
        left: 0
        width: 640
        height: 800

      console.log "Opening " + url + " ..."
      page.open url, (status) ->
        console.log "Rendering screenshot ..."
        setTimeout (->
          page.render previewPath, ->
            page.close()
            setTimeout (->
              res.sendfile filepath,
                root: __dirname + DEST_ROOT

              return
            ), 10
            return

        ), 500


  DEST_ROOT = "../../"
  filepath = folder + "/" + filename
  previewPath = DEST_ROOT + filepath
  if phantomInstance
    snapShot()
  else
    phantomCallbacks.push snapShot
  return