Contents

require_relative 'as/csv'

module DbMod
  # Contains coercers and other functions that allow
  # module instance methods returning an SQL result set
  # to be extended with additional result coercion and
  # formatting. The normal way to access this functionality
  # is via {DbMod::Statements::ConfigurableMethod#as},
  # which is available when defining a statement method
  # or prepared method:
  #
  #  def_statement(:a, 'SELECT a, b, c FROM foo').as(:csv)
  #  def_prepared(:b, 'SELECT d, e, f FROM bar').as(:csv)
  module As
    # List of available result coercion methods.
    # Only keys defined here are allowed as arguments
    # to {DbMod::Statements::ConfigurableMethod#as}.
    COERCERS = {
      csv: DbMod::As::Csv
    }

    # Extend a method so that the SQL result set it
    # returns will be coerced to the given type.
    # See {COERCERS} for a list of defined coercion
    # methods.
    #
    # @param mod [Module] module where the method has been defined
    # @param name [Symbol] method name
    # @param type [Symbol] type to which result set should be coerced
    def self.extend_method(mod, name, type)
      unless COERCERS.key? type
        fail ArgumentError, "#{type} not in #{COERCERS.keys.join ', '}"
      end

      Statements.extend_method(mod, name, COERCERS[type])
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

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