Contents

module DbMod
  module As
    # Coercer which converts an SQL result set
    # into a string formatted as a CSV document.
    # May be enabled for a prepared method or
    # statement method using +.as(:csv)+:
    #
    #  def_statement(:a, 'SELECT a, b FROM foo').as(:csv)
    #  def_prepared(:b, 'SELECT b, c FROM bar').as(:csv)
    #
    #  def do_stuff
    #    a # => "a,b\r\n1,2\r\n3,4\r\n..."
    #  end
    module Csv
      # Enables this module to be passed to {DbMod::Statements.extend_method}
      # as the +wrapper+ function, in which case it will retrieve the results
      # and format them as a CSV document using the column names from the
      # result set.
      #
      # @param wrapped_method [Method] the method that has been wrapped
      # @param args [*] arguments expected to be passed to the wrapped method
      # @return [String] a CSV formatted document
      def self.call(wrapped_method, *args)
        results = wrapped_method.call(*args)

        headers = nil
        CSV.generate do |csv|
          results.each do |row|
            csv << (headers = row.keys) unless headers

            csv << headers.map { |col| row[col] }
          end
        end
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
db_mod-0.0.3	lib/db_mod/as/csv.rb