screenshots.js

'use strict';

var system  = require('system');
var webpage = require('webpage');
var fs      = require('fs');


var configFile,
    configPath,
    currentActionCounter,
    scriptArguments,
    totalActionsCounter;


function joinUrlElements() {
  var isAbsolute = false;
  var regex      = new RegExp('^\\/|\\/$','g');
  var paths      = Array.prototype.slice.call(arguments);
  var url        = '';

  if (paths[0][0] === '/') {
    isAbsolute = true;
  }

  url = paths.map(function(element){
    return element.replace(regex,"");
  }).join('/');

  if (isAbsolute) {
    url = '/' + url;
  }

  return url;
}

function takeAScreenshot(address, output, size, zoom, timer) {
  var page = webpage.create();

  totalActionsCounter++;

  console.log('started ' + output + ' screenshot');

  page.viewportSize = { width: size.width, height: size.height };
  page.zoomFactor   = zoom;

  page.open(address, function (status) {
    if (status !== 'success') {
      console.log('Error: Unable to load the address ' + address);
      return false;
    } else {
      window.setTimeout(function () {
        page.render(output);
        console.log('finished ' + output + ' screenshot');
        setTimeout(function() {
          page.close();
          currentActionCounter++;
          if (currentActionCounter === totalActionsCounter) {
            phantom.exit();
          }
        }, 1);
        return true;
      }, timer);
    }
  });
}

function launchScreenshotsSeries(conf) {
  var currentDevice,
  currentView,
  fullUrl,
  outputFolder,
  outputPath,
  size,
  zoom;

  var baseFolder = 'render/' + conf.baseFolder;
  var baseUrl    = conf.baseUrl;
  var devices    = conf.devices;
  var viewsList  = conf.viewsList;
  var timer      = conf.pageLoadingTimer;

  totalActionsCounter  = 0;
  currentActionCounter = 0;

  for (var i = devices.length - 1; i >= 0; i--) {
    currentDevice = devices[i];
    size          = currentDevice.size;
    zoom          = currentDevice.pixelDensity;
    outputFolder  = joinUrlElements(baseFolder, currentDevice.name);

    for (var j = viewsList.length - 1; j >= 0; j--) {
      currentView = viewsList[j];
      outputPath  = joinUrlElements(outputFolder, currentView.name) + '.png';
      fullUrl     = joinUrlElements(baseUrl, currentView.url);
      takeAScreenshot(fullUrl, outputPath, size, zoom, timer);
    }
  }

  return true;
}

scriptArguments = system.args;

if (scriptArguments.length !== 2) {
  console.log('Usage: screenshots.js path-to-config-file');
  phantom.exit();
} else {

  // system.args contains the current script file name so we get directly the second argument
  configPath = scriptArguments[1];

  if (!fs.exists(configPath)) {
    console.log('Error: couldn\'t find config file at ' + configPath);
  } else {
    configFile = JSON.parse(fs.read(configPath));
    launchScreenshotsSeries(configFile);
  }

}