Class: Photograph::Artist

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

Defined Under Namespace

Classes: DeprecationError, MissingUrlError

Constant Summary collapse

DefaultOptions = 
{
 :x => 0,          # top left position
 :y => 0,
 :w => 1280,       # width
 :h => 1024,       # height

 :sleep => 0.5,    # Sleep 0.5 seconds before taking the screenshot
 :capybara_wait_time => 15, # Default Capybara wait time
 :selector => nil  # wait until the selector matches to take the screenshot
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Artist

Creates a new Photograph::Artist and configures it through options.

Cropping is supported through the x, y, w and h options.

Options:

  • url mandatory, location you want to screenshot

  • sleep sleep amount of seconds before screenshotting. *this is option is ignored if selector is provided.

  • selector wait until the provided selector matches a dom node before screenshotting. Typically faster than an arbritrary wait amount, used when your page has some dynamically inserted nodes.

  • capybara_wait_time time capybara will wait for a a selector to appear before timing out

  • x top coordinate of the screenshot, default to 0

  • y left coordinate of the screenshot, default to 0

  • w width of the screenshot, default to 1280

  • h height of the screenshot, default to 1024

  • browser Capybara instance to use, typically instanciated by Artist.create_browser

Raises:



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# File 'lib/photograph/artist.rb', line 66

def initialize options={}
  raise MissingUrlError.new('missing argument :url') unless options[:url]
  if options[:wait]
    $stderr.puts "DEPRECATED: the :wait option had been deprecated and will be ignored in further version, please use :sleep instead."
  end

  @options = DefaultOptions.merge(options)
  @options[:url] = normalize_url(options[:url])
end

Instance Attribute Details

#image ⇒ Object (readonly)

Returns the value of attribute image.



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# File 'lib/photograph/artist.rb', line 7

def image
  @image
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/photograph/artist.rb', line 6

def options
  @options
end

Class Method Details

.create_browser ⇒ Object

Instanciate a browser instance.

Typically it’s used to supply a Photograph instance your own browser session, allowing you to reuse it if you’re using multiples Photograph::Artist instances.



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# File 'lib/photograph/artist.rb', line 29

def self.create_browser
  Capybara::Session.new :poltergeist
end

Instance Method Details

#adjust_image(tempfile) ⇒ Object

Crops a given tempfile according to initially given options



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# File 'lib/photograph/artist.rb', line 110

def adjust_image tempfile
  image = MiniMagick::Image.read tempfile

  if options[:h] && options[:w]
    image.crop "#{options[:w]}x#{options[:h]}+#{options[:x]}+#{options[:y]}"
    image.write tempfile
  end

  image
end

#before(&block) ⇒ Object 



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# File 'lib/photograph/artist.rb', line 121

def before &block
  @before_hook = block
end

#browser ⇒ Object

Returns current browser instance.

If none had been supplied, it creates a new one.



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# File 'lib/photograph/artist.rb', line 37

def browser
  @options[:browser] ||= self.class.create_browser
end

#normalize_url(url) ⇒ Object

Normalize urls, allowing you to use “google.com” instead of “google.com”



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# File 'lib/photograph/artist.rb', line 43

def normalize_url url
  unless url.match(/https?:\/\//)
    url = "http://#{url}"
  end

  url
end

#shoot!(&block) ⇒ Object

Takes a screenshot and yield the resulting image.

Raises:



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# File 'lib/photograph/artist.rb', line 78

def shoot! &block
  raise DeprecationError.new('Using Artist#shoot! without a block had been deprecated') unless block_given?

  Capybara.using_wait_time @options[:capybara_wait_time] do
    begin
      browser.visit @options[:url]

      @before_hook.call(browser) if @before_hook

      if @options[:selector]
        browser.wait_until do
          browser.has_css? @options[:selector]
        end
      else
        sleep @options[:sleep]
      end

      tempfile = Tempfile.new(['photograph','.png'])

      browser.driver.render tempfile.path,
        :width  => options[:w] + options[:x],
        :height => options[:h] + options[:y]

      yield adjust_image(tempfile)
    ensure
      tempfile.unlink if tempfile
    end
  end
end