Class: KMZCompressor::Middleware

Inherits:
Object
  • Object
show all
Defined in:
lib/kmz_compressor/middleware.rb

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Middleware

Returns a new instance of Middleware.



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# File 'lib/kmz_compressor/middleware.rb', line 3

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/kmz_compressor/middleware.rb', line 7

def call(env)
  request = Rack::Request.new(env)

  # If the User is asking for a KMZ file
  if request.path_info.end_with? '.kmz'
    uri = request.url

    # Use a hash of the request path (before we gsub it) as the filename we will save on the HD
    cache_path = "public/kmz/#{Digest::SHA2.hexdigest(uri)}.kmz"
    file_exists = File.exists?(cache_path)

    if file_exists
      status = 200
      headers = {'Last-Modified' => File.mtime(cache_path).httpdate}
      response = File.open(cache_path)
    else
      # Ask Rails for KML instead of KMZ
      request.path_info = request.path_info.gsub(/kmz\Z/, 'kml')
      status, headers, response = @app.call(env)
      status = status.to_i
    end

    if status == 200
      # Set the Content-Type to KMZ
      headers['Content-Type'] = 'application/vnd.google-earth.kmz'
    end

    if status == 200 && !file_exists
      # Zip the KML response and save it on the HD
      FileUtils.mkdir_p(File.dirname(cache_path))
      Zip::File.open(cache_path, Zip::File::CREATE) do |zipfile|
        zipfile.get_output_stream("doc.kml") { |os| os.write response.body }
      end
      response = [File.open(cache_path).read]
    end

    # Allow Cross-Domain HEAD/GET requests to support subdomains
    headers['Access-Control-Allow-Origin'] ||= '*'
    headers['Access-Control-Request-Method'] ||= %w{HEAD GET}.join(",")

    # Return the response to the next middleware in the chain
    [status, headers, response]
  else
    @app.call(env)
  end
end