Class: OSX::Screenshot

Inherits:
Object
  • Object
show all
Defined in:
lib/osxscreenshot.rb

Defined Under Namespace

Classes: CommandFailed

Constant Summary collapse

VERSION = 
'0.0.5'

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(url, options) ⇒ Screenshot

Returns a new instance of Screenshot.



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# File 'lib/osxscreenshot.rb', line 40

def initialize(url, options)
  vendored_webkit2png = File.expand_path(File.join(File.dirname(__FILE__),
                                                   "..",
                                                   "vendor",
                                                   "webkit2png.py"))
  @url = url
  @options = {
    :tmpdir     => "/tmp",
    :webkit2png => vendored_webkit2png,
    :mogrify    => "mogrify",
    :width      => 320,
    :height     => 480,
    :timeout    => 30
  }.merge(options)
end

Class Method Details

.capture(url, options = {}) ⇒ Object

Takes a screenshot of a website, optionally resizes it, and writes it to a temporary directory. Returns the file path to the temporary file.

It’s assumed that you will move the file to a permanent destination or store it in a database.

Options include:

tmpdir

Path to tmp directory where files will be stored

webkit2png

Path to webkit2png.py command

mogrify

Path to mogrify command

Usage:

output_screenshot_path =
  OSX::Screenshot.capture(article_url, {
                     :tmpdir     => "#{Sinatra::Application.root}/tmp",
                     :webkit2png => "#{Sinatra::Application.root}/bin/webkit2png.py",
                     :mogrify    => "/opt/local/bin/mogrify",
                     :width      => 220,
                     :height     => 270
                   })
system "mv #{output_screenshot_path} #{local_path}"



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# File 'lib/osxscreenshot.rb', line 35

def self.capture(url, options={})
  obj = new(url, options)
  obj.capture
end

Instance Method Details

#capture ⇒ Object 



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# File 'lib/osxscreenshot.rb', line 56

def capture
  random_id        = [@url.length, Time.now.to_i.to_s, rand(10000)].join('-')
  tmp_abs_filename = File.join(@options[:tmpdir], "#{random_id}-full.png")
  tmp_dir          = File.dirname(tmp_abs_filename)
  FileUtils.mkdir_p(tmp_dir)

  webkit2png_command = [@options[:webkit2png],
                        "--full",
                        "--filename",    random_id,
                        "--dir",         @options[:tmpdir],
                        @url
                       ].join(' ')

  run_command(webkit2png_command) do
    return resize(tmp_abs_filename, @options[:width], @options[:height])
  end
end

#resize(tmp_abs_filename, width, height) ⇒ Object 



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# File 'lib/osxscreenshot.rb', line 74

def resize(tmp_abs_filename, width, height)
  # Example: mogrify -resize 320x peepcodecom-full.png -crop 320x480 peepcodecom-full.png

  mogrify_command = [@options[:mogrify],
                     "-resize", "#{width}x",
                     tmp_abs_filename,
                     "-crop",   "#{width}x#{height}",
                     tmp_abs_filename
                    ].join(' ')
  run_command(mogrify_command) do
    output_filename = if File.exist?(tmp_abs_filename)
                        # Add full width and height to image
                        extent_command = [@options[:mogrify],
                                          "-extent", "#{width}x#{height}",
                                          tmp_abs_filename].join(' ')
                        run_command(extent_command) { return tmp_abs_filename }
                      elsif File.exist?(tmp_abs_filename.gsub(/\.png/, '-0.png'))
                        # Remove extra file generated by cropping.
                        FileUtils.rm(tmp_abs_filename.gsub(/\.png/, '-1.png'))
                        tmp_abs_filename.gsub(/\.png/, '-0.png')
                      end
    return output_filename
  end
end

#run_command(cmd, &block) ⇒ Object 



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# File 'lib/osxscreenshot.rb', line 99

def run_command(cmd, &block)
  pid = nil
  status = nil

  Timeout.timeout(@options[:timeout]) {
    pid, i, o, e = open4(cmd)
    ignored, status = Process::waitpid2 pid
  }
  
  # Success
  if (status.exitstatus == 0)
    return yield
  end
  
  # Error
  raise CommandFailed, "Command failed: #{cmd}"
rescue Timeout::Error => e
  Process.kill "KILL", pid
  Process.wait pid
  return nil
end