Google Fonts helper

google_fonts_helper.rb

def google_fonts(*query)
    raise ArgumentError, 'Expected at least one font.' if query.empty?
    if query.first.is_a? Hash
      query = [*query.first].transpose
      query = [query.first, query.last.to_enum]
    end
    api_base_url = 'http://fonts.googleapis.com/css'
    # Iterate through given font families, building the query string from them and given styles
    query_string = '?family=' + [*query.first].collect { |family|
      # Stringify and title-case family name, replacing underscores with spaces
      family_str = family.to_s.split(/ |_/).map(&:capitalize).join('+')
      # Append any given styles to current font family string
      if query[1]
        # Using an Enumerator allows for mapping different styles to each font family
        styles = query.last.is_a?(Enumerator) ? query.last.next : query.last
        # [API] styles are enumerated after a colon, and delineated by a comma
        family_str << ':' << [*styles].join(',')
      end
      family_str
    }.join('|') # [API] families are separated by the pipe character
    %Q[<link rel="stylesheet" type="text/css" href="#{api_base_url + query_string}" />]
end