Class: Webshot::Screenshot

Inherits:
Object
  • Object
show all
Includes:
Capybara::DSL, Singleton
Defined in:
lib/webshot/screenshot.rb

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ Screenshot 



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# File 'lib/webshot/screenshot.rb', line 8

def initialize(opts = {})
  Webshot.capybara_setup!
  width  = opts.fetch(:width, Webshot.width)
  height = opts.fetch(:height, Webshot.height)
  user_agent = opts.fetch(:user_agent, Webshot.user_agent)

  # Browser settings
  page.driver.resize(width, height)
  page.driver.headers = {
    "User-Agent" => user_agent
  }
end

Instance Method Details

#capture(url, path, opts = {}) ⇒ Object

Captures a screenshot of url saving it to path.



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# File 'lib/webshot/screenshot.rb', line 36

def capture(url, path, opts = {})
  begin
    # Default settings
    width   = opts.fetch(:width, 120)
    height  = opts.fetch(:height, 90)
    gravity = opts.fetch(:gravity, "north")
    quality = opts.fetch(:quality, 85)
    full = opts.fetch(:full, true)
    selector = opts.fetch(:selector, nil)
    allowed_status_codes = opts.fetch(:allowed_status_codes, [])

    # Reset session before visiting url
    Capybara.reset_sessions! unless @session_started
    @session_started = false

    # Open page
    visit url

    # Timeout
    sleep opts[:timeout] if opts[:timeout]

    # Check response code
    status_code = page.driver.status_code.to_i
    unless valid_status_code?(status_code, allowed_status_codes)
      fail WebshotError, "Could not fetch page: #{url.inspect}, error code: #{page.driver.status_code}"
    end

    tmp = Tempfile.new(["webshot", ".png"])
    tmp.close
    begin
      screenshot_opts = { full: full }
      screenshot_opts = screenshot_opts.merge({ selector: selector }) if selector

      # Save screenshot to file
      page.driver.save_screenshot(tmp.path, screenshot_opts)

      # Resize screenshot
      thumb = MiniMagick::Image.open(tmp.path)
      if block_given?
        # Customize MiniMagick options
        yield thumb
      else
        thumb.combine_options do |c|
          c.thumbnail "#{width}x"
          c.background "white"
          c.extent "#{width}x#{height}"
          c.gravity gravity
          c.quality quality
        end
      end

      # Save thumbnail
      thumb.write path
      thumb
    ensure
      tmp.unlink
    end
  rescue Capybara::Poltergeist::StatusFailError, Capybara::Poltergeist::BrowserError, Capybara::Poltergeist::DeadClient, Capybara::Poltergeist::TimeoutError, Errno::EPIPE => e
    # TODO: Handle Errno::EPIPE and Errno::ECONNRESET
    raise WebshotError.new("Capybara error: #{e.message.inspect}")
  end
end

#start_session(&block) ⇒ Object 



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# File 'lib/webshot/screenshot.rb', line 21

def start_session(&block)
  Capybara.reset_sessions!
  Capybara.current_session.instance_eval(&block) if block_given?
  @session_started = true
  self
end

#valid_status_code?(status_code, allowed_status_codes) ⇒ Boolean 



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# File 'lib/webshot/screenshot.rb', line 28

def valid_status_code?(status_code, allowed_status_codes)
  return true if status_code == 200
  return true if status_code / 100 == 3
  return true if allowed_status_codes.include?(status_code)
  false
end