Background print is use for print page without open in tab. Its purpose use for print PDF.

background_print.coffee

# new BackgroundPrint('http://book.pdf').print()
class window.BackgroundPrint
  constructor: (url)->
    @url = url

  print: ->
    @_createFrame()
    @_handleFrameLoad()
    @_loadFrame()
    
  _createFrame: ->
    @iframe  = document.createElement('iframe')
    document.body.appendChild @iframe
    @iframe.style.display = 'none'

  _handleFrameLoad: ->
    service = @
    @iframe.onload = ->
      setTimeout((->
        service.iframe.focus()
        service.iframe.contentWindow.print()
      ), 1)

  _loadFrame: ->
    @iframe.src = @url