@@ -70,7 +70,7 @@ is equivalent to: ==== attr_reader -This method is equivalent to calling <tt>battr(symbol, false)</tt> on each symbol in +This method is equivalent to calling <tt>attr(symbol, false)</tt> on each symbol in turn. For example, module Mod README.rdoc @@ -1,22 +1,54 @@ module PluginAWeek #:nodoc: module AttributePredicates - module ActiveRecord - private - # For Strings, returns true when value is: - # * "true" - # * "t" - # - # For Integers, returns true when value is: - # * 1 - def attr_predicate(symbol) - define_method("#{symbol}?") do - ::ActiveRecord::ConnectionAdapters::Column.value_to_boolean(instance_variable_get("@#{symbol}")) + module Extensions + # Adds support for automatically defining predicate methods using +attr_predicate+ + # when defining attributes using +attr+, +attr_reader+, +attr_reader+, and + # +attr_accessor+. In comparison to normal Ruby attributes, ActiveRecord + # predicates use a different system for defining true/false. + # + # == Examples + # + # The predicate methods for attributes use ActiveRecord's type conversion + # for booleans for determing whether to return true or false. For example, + # + # class Person < ActiveRecord::Base + # attr_accessor :value + # end + # + # >> p = Person.new + # >> p.value = false + # >> p.value? + # => false + # >> p.value = 'false' + # >> p.value? + # => false + # >> p.value = 'true' + # >> p.value? + # => true + # >> p.value = 't' + # >> p.value? + # => true + # >> p.value = 1 + # >> p.value? + # => true + module ActiveRecord + private + # For Strings, returns true when value is: + # * "true" + # * "t" + # + # For Integers, returns true when value is: + # * 1 + def attr_predicate(symbol) + define_method("#{symbol}?") do + ::ActiveRecord::ConnectionAdapters::Column.value_to_boolean(instance_variable_get("@#{symbol}")) + end end - end + end end end end ActiveRecord::Base.class_eval do - extend PluginAWeek::AttributePredicates::ActiveRecord + extend PluginAWeek::AttributePredicates::Extensions::ActiveRecord end if defined?(ActiveRecord) lib/attribute_predicates/extensions/active_record.rb @@ -1,37 +1,73 @@ module PluginAWeek #:nodoc: module AttributePredicates - module Module - def self.included(base) #:nodoc: - base.class_eval do - [:attr, :attr_reader, :attr_writer, :attr_accessor].each do |method| - alias_method_chain method, :predicates + module Extensions + # Adds support for automatically defining predicate methods using +attr_predicate+ + # when defining attributes using +attr+, +attr_reader+, +attr_reader+, and + # +attr_accessor+. + # + # == Examples + # + # The predicate methods for attributes checks whether the value is blank? + # for determining whether true or false should be returned. For example, + # + # class Person + # attr_accessor :value + # end + # + # >> p = Person.new + # >> p.value = false + # >> p.value? + # => false + # >> p.value = true + # >> p.value? + # => true + # >> p.value = [] + # >> p.value? + # => false + # >> p.value = [false] + # >> p.value? + # => true + module Module + def self.included(base) #:nodoc: + base.class_eval do + [:attr, :attr_reader, :attr_writer, :attr_accessor].each do |method| + alias_method_chain method, :predicates + end end end - end - - def attr_with_predicates(*args) #:nodoc: - attr_without_predicates(*args) - attr_predicate(args.first) - end - - [:attr_reader, :attr_writer, :attr_accessor].each do |method| - define_method("#{method}_with_predicates") do |*symbols| - send("#{method}_without_predicates", *symbols) - symbols.each {|symbol| attr_predicate(symbol)} + + # Defines a predicate method, using +attr_predicate+, in addition to the + # attribute accessors. For example, + # + # module Mod + # attr :is_okay + # end + # + # Mod.instance-methods.sort #=> ["is_okay", "is_okay?"] + def attr_with_predicates(*args) + attr_without_predicates(*args) + attr_predicate(args.first) end - end - - private - # Returns true if the specified variable is not blank, otherwise false - def attr_predicate(symbol) - define_method("#{symbol}?") do - !instance_variable_get("@#{symbol}").blank? + + [:attr_reader, :attr_writer, :attr_accessor].each do |method| + define_method("#{method}_with_predicates") do |*symbols| + send("#{method}_without_predicates", *symbols) + symbols.each {|symbol| attr_predicate(symbol)} end end + + private + # Returns true if the specified variable is not blank, otherwise false + def attr_predicate(symbol) + define_method("#{symbol}?") do + !instance_variable_get("@#{symbol}").blank? + end + end + end end end end ::Module.class_eval do - include PluginAWeek::AttributePredicates::Module + include PluginAWeek::AttributePredicates::Extensions::Module end lib/attribute_predicates/extensions/module.rb b3e6ec7fc5af31c227e2e34078af1d8bd307b3da Aaron Pfeifer aaron.pfeifer@gmail.com http://github.com/pluginaweek/attribute_predicates/commit/8378588b045cf7402bdd05b640138bb7e73a756f 8378588b045cf7402bdd05b640138bb7e73a756f 2008-07-04T14:36:59-07:00 2008-07-04T14:36:59-07:00 Add more documentation 084686431ff06e2d0a0f1779d37cc866f9f0182a Aaron Pfeifer aaron.pfeifer@gmail.com