Class: NewRelic::Rack::BrowserMonitoring

Inherits:
Object
  • Object
show all
Defined in:
lib/new_relic/rack/browser_monitoring.rb

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ BrowserMonitoring

Returns a new instance of BrowserMonitoring.



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# File 'lib/new_relic/rack/browser_monitoring.rb', line 6

def initialize(app, options = {})
  @app = app
end

Instance Method Details

#autoinstrument_source(response, headers) ⇒ Object 



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# File 'lib/new_relic/rack/browser_monitoring.rb', line 43

def autoinstrument_source(response, headers)
  source = nil
  response.each {|fragment| source ? (source << fragment.to_s) : (source = fragment.to_s)}
  return nil unless source
  
  body_start = source.index("<body")
  body_close = source.rindex("</body>")

  if body_start && body_close
    footer = NewRelic::Agent.browser_timing_footer
    header = NewRelic::Agent.browser_timing_header
              
    if source.include?('X-UA-Compatible')
      # put at end of header if UA-Compatible meta tag found
      head_pos = source.index("</head>")          
    elsif head_open = source.index("<head")
      # put at the beginning of the header
      head_pos = source.index(">", head_open) + 1
    else
      # put the header right above body start
      head_pos = body_start
    end

    source = source[0..(head_pos-1)] + header + source[head_pos..(body_close-1)] + footer + source[body_close..-1]

    headers['Content-Length'] = source.length.to_s if headers['Content-Length']
  end

  source
end

#call(env) ⇒ Object

method required by Rack interface



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# File 'lib/new_relic/rack/browser_monitoring.rb', line 11

def call(env)
  # Two experimental options for allowing TT capture based on http params
  #
  # if req.params['nr_capture_deep_tt']
    # NewRelic::Agent::TransactionInfo.get.force_persist = true
    # NewRelic::Agent::TransactionInfo.get.capture_deep_tt = true
  # end
  
  # if req.params['nr_capture_tt']
    # NewRelic::Agent::TransactionInfo.get.force_persist = true
  # end
  
  result = @app.call(env)   # [status, headers, response]
  
  if (NewRelic::Agent.browser_timing_header != "") && should_instrument?(result[0], result[1])
    response_string = autoinstrument_source(result[2], result[1])

    if response_string
      response = Rack::Response.new(response_string, result[0], result[1])
      response.finish
    else
      result
    end
  else
    result
  end
end

#should_instrument?(status, headers) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/new_relic/rack/browser_monitoring.rb', line 39

def should_instrument?(status, headers)
  status == 200 && headers["Content-Type"] && headers["Content-Type"].include?("text/html")
end