Class: CriticalPathCss::CssFetcher

Inherits:
Object
  • Object
show all
Defined in:
lib/critical_path_css/css_fetcher.rb

Constant Summary collapse

GEM_ROOT = 
File.expand_path(File.join('..', '..'), File.dirname(__FILE__))

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ CssFetcher

Returns a new instance of CssFetcher.



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# File 'lib/critical_path_css/css_fetcher.rb', line 8

def initialize(config)
  @config = config
end

Instance Method Details

#fetch ⇒ Object 



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# File 'lib/critical_path_css/css_fetcher.rb', line 12

def fetch
  @config.routes.map { |route| [route, fetch_route(route)] }.to_h
end

#fetch_route(route) ⇒ Object 



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# File 'lib/critical_path_css/css_fetcher.rb', line 16

def fetch_route(route)
  options = {
    'url' => @config.base_url + route,
    'css' => @config.path_for_route(route),
    'width' => 1300,
    'height' => 900,
    'timeout' => 30_000,
    # CSS selectors to always include, e.g.:
    'forceInclude' => [
      #  '.keepMeEvenIfNotSeenInDom',
      #  '^\.regexWorksToo'
    ],
    # set to true to throw on CSS errors (will run faster if no errors)
    'strict' => false,
    # characters; strip out inline base64 encoded resources larger than this
    'maxEmbeddedBase64Length' => 1000,
    # specify which user agent string when loading the page
    'userAgent' => 'Penthouse Critical Path CSS Generator',
    # ms; render wait timeout before CSS processing starts (default: 100)
    'renderWaitTime' => 100,
    # set to false to load (external) JS (default: true)
    'blockJSRequests' => true,
    'customPageHeaders' => {
      # use if getting compression errors like 'Data corrupted':
      'Accept-Encoding' => 'identity'
    }
  }.merge(@config.penthouse_options)
  out, err, st = Dir.chdir(GEM_ROOT) do
    Open3.capture3('node', 'lib/fetch-css.js', JSON.dump(options))
  end
  if !st.exitstatus.zero? || out.empty? && !err.empty?
    STDOUT.puts out
    STDERR.puts err
    STDERR.puts "Failed to get CSS for route #{route}\n" \
          "  with options=#{options.inspect}"
  end
  out
end