screenshots.js

/*
* Takes provided URL passed as argument and make full height screenshots of this page 
* with several viewport widths.
*
* These viewport widths are taken from common android and iOS devices. Modify as needed.
*
* Takes an optional second argument for the path where screenshots are saved.
*
* Usage:
* $ casperjs screenshots.js http://example.com
* $ casperjs screenshots.js http://example.com directory/to/save
*/

var casper = require("casper").create();

var screenshotUrl = '',
    screenshotNow = new Date(),
    screenshotDateTime = screenshotNow.getFullYear() + pad(screenshotNow.getMonth() + 1) + pad(screenshotNow.getDate()) + '-' + pad(screenshotNow.getHours()) + pad(screenshotNow.getMinutes()) + pad(screenshotNow.getSeconds()),
    save_directory = screenshotDateTime,
    viewport_widths = [240, 320, 360, 568, 603, 640, 768, 800, 960, 1024, 1280, 1400, 1600, 1920];

if (casper.cli.args.length < 1) {
  casper
    .echo("Usage: $ casperjs screenshots.js http://example.com")
    .exit(1)
  ;
} else {
  screenshotUrl = casper.cli.args[0];
}

if (casper.cli.args.length >= 2) {
  save_directory = casper.cli.args[1];
}

casper.start(screenshotUrl, function() {
  this.echo('Current location is ' + this.getCurrentUrl(), 'info');
});

casper.each(viewport_widths, function(casper, width) {
  this.then(function() {
    this.viewport(width, 100);
  });
  this.thenOpen(screenshotUrl, function() {
    this.wait(5000);
  });
  this.then(function(){
    this.echo('Screenshot for width:' + width, 'info');
    this.capture('screenshots/' + save_directory + '/' + width + '.png');
  });
});

casper.run();

function pad(number) {
  var r = String(number);
  if ( r.length === 1 ) {
    r = '0' + r;
  }
  return r;
}