Class: Phrender::PhantomJSEngine

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

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ PhantomJSEngine

Returns a new instance of PhantomJSEngine.



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# File 'lib/phrender/phantom_js_engine.rb', line 10

def initialize(opts = {})
  # Apply defaults
  opts = { :timeout => 10000, :ssl => false }.merge opts

  @poll_interval = 0.1
  @timeout = opts[:timeout] / 1000.0
  @ssl_protocol = opts.delete :ssl
  @logger = Phrender::Logger

  phantom_program = File.expand_path '../support/phantom_bridge.js', __FILE__

  MultiJson.use :json_gem

  @boot_cmd = [
    'phantomjs',
    phantom_program,
    "--ignore-ssl-errors=true",
    "--load-images=false"
  ]
  @boot_cmd.push "--ssl-protocol=%s" % [ @ssl_protocol ] if @ssl_protocol
end

Instance Method Details

#render(html, javascript, url = nil) ⇒ Object 



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# File 'lib/phrender/phantom_js_engine.rb', line 32

def render(html, javascript, url = nil)
  javascript_file = make_temp_file(javascript, 'file.js')
  html_file = make_temp_file(html, 'file.html')
  program_options = { :html => html_file.path,
                      :javascript => javascript_file.path,
                      :url => url,
                      :timeout => @timeout * 1000.0 }

  session = Phrender::PhantomJSSession.new @boot_cmd.join(' '), @timeout

  session.stdin.puts MultiJson.dump(program_options)
  session.stdin.close

  begin
    sleep @poll_interval
    parse_output(session)
  end while !session.expired? && !session.rendered

  # Clean up phantom
  session.shutdown

  # Clean up temp files
  javascript_file.unlink
  html_file.unlink

  # Feed something out the chain
  if session.rendered
    session.page
  elsif session.expired?
    @logger.critical "PhantomJS timed out. Likely a javascript execution error."
    ''
  else
    @logger.critical "Phantom terminated without expiring or returning anything. This is bad."
    ''
  end
end