Class: Mathjax_Renderer::Renderer

Inherits:
Object
  • Object
show all
Includes:
Capybara::DSL
Defined in:
lib/mathjax_renderer/renderer.rb

Instance Method Summary collapse

Constructor Details

#initialize(mathml, image_base_url = nil, options = {}) ⇒ Renderer

Returns a new instance of Renderer.



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# File 'lib/mathjax_renderer/renderer.rb', line 9

def initialize(mathml, image_base_url = nil, options = {})
  @mathml = mathml
  @image_base_url = image_base_url
  @options = {min_width: 0, extra_style:'', padding:0}.merge options
end

Instance Method Details

#html ⇒ Object 



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# File 'lib/mathjax_renderer/renderer.rb', line 92

def html
  return cached(params_hash) if cached? params_hash

  render! if @html.nil?

  @html
end

#image_name ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/mathjax_renderer/renderer.rb', line 15

def image_name
  raise ArgumentError if @image_base_url.nil?
  render! unless File.exist?(image_path)
  _image_name
end

#mathjax_ready?(page) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mathjax_renderer/renderer.rb', line 37

def mathjax_ready?(page)
	html = Nokogiri::HTML(page.html)
	!html.css('.MathJax').empty? &&
		html.css('.MathJax_Processing').empty? &&
		html.css('.MathJax_Processed').empty?
end

#render! ⇒ Object 



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# File 'lib/mathjax_renderer/renderer.rb', line 21

def render!
  server = RendererServer.new
  server.ensure_started!

  url = server.add_content(@mathml, @options[:extra_style], @options[:padding])

			require 'phantomjs/poltergeist'
			require 'phantomjs'
			Capybara.register_driver :poltergeist do |app|
Capybara::Poltergeist::Driver.new(app, :phantomjs => Phantomjs.path)
			end
			Capybara.default_driver = :poltergeist
			Capybara.app_host = "http://localhost:#{server.port}"

			visit url

			def mathjax_ready?(page)
html = Nokogiri::HTML(page.html)
!html.css('.MathJax').empty? &&
	html.css('.MathJax_Processing').empty? &&
	html.css('.MathJax_Processed').empty?
			end

			Timeout.timeout(5) do
sleep 0.1 until mathjax_ready?(page)
			end

			unless @image_base_url.nil?
require 'chunky_png'
driver = page.driver

require 'fileutils'
FileUtils.mkpath @image_base_url

driver.save_screenshot(image_path)

image = ChunkyPNG::Image.from_file(image_path)

location = page.driver.evaluate_script <<-EOS
	function() {
		var ele  = document.querySelector('.MathJax .math');
		var rect = ele.getBoundingClientRect();
		return [rect.left, rect.top];
	}();
EOS

size = page.driver.evaluate_script <<-EOS
	function() {
		var ele  = document.querySelector('.MathJax .math');
		var rect = ele.getBoundingClientRect();
		return [rect.width, rect.height];
	}();
EOS

correction = [(@options[:min_width] -(size[0] + 2 * @options[:padding])) / 2,0].max

x = location[0] + 1 - @options[:padding]-correction
y = location[1] + 1 - @options[:padding]
width = [size[0].ceil + 2 * @options[:padding],@options[:min_width]].max
height = size[1]+ 2 * @options[:padding]

image.crop!(x, y, width, height)
image.save(image_path)
			end
			result = Nokogiri::HTML(page.html).css('.MathJax .math')[0]

			put_cache!(params_hash,result)

			@html = result
end