meta-programming
in [Ruby]
|
From: Brian Candler on 15 Dec 2009 06:35 Jesús Gabriel y Galán wrote: > irb(main):051:0> C.add_method(:name) {@name} > => #<Proc:0xb7cb9de8@(irb):51> > irb(main):052:0> C.add_method(:name=) {|value| @name = value} > => #<Proc:0xb7cb3bf0@(irb):52> > irb(main):053:0> c = C.new > => #<C:0xb7cb16d4> > irb(main):054:0> c.name=3 > => 3 > irb(main):055:0> c.name > => 3 Of course, since 'name' is static here, you could just include a module. It gets more fun when the names of the accessors themselves are dynamic. At this point it really does make more sense to use string eval, rather than the alternative (instance_variable_get and instance_variable_set). Have a look at define_method_attribute= in the following: http://github.com/rails/rails/blob/master/activerecord/lib/active_record/attribute_methods/write.rb Also see define_read_method in attribute_methods/read.rb, and method_missing in base.rb (this defines finder methods dynamically) -- Posted via http://www.ruby-forum.com/.
From: Rajinder Yadav on 15 Dec 2009 06:55
Brian Candler wrote: > Jesús Gabriel y Galán wrote: >> irb(main):051:0> C.add_method(:name) {@name} >> => #<Proc:0xb7cb9de8@(irb):51> >> irb(main):052:0> C.add_method(:name=) {|value| @name = value} >> => #<Proc:0xb7cb3bf0@(irb):52> >> irb(main):053:0> c = C.new >> => #<C:0xb7cb16d4> >> irb(main):054:0> c.name=3 >> => 3 >> irb(main):055:0> c.name >> => 3 > > Of course, since 'name' is static here, you could just include a module. > > It gets more fun when the names of the accessors themselves are dynamic. > At this point it really does make more sense to use string eval, rather > than the alternative (instance_variable_get and instance_variable_set). > > Have a look at define_method_attribute= in the following: > http://github.com/rails/rails/blob/master/activerecord/lib/active_record/attribute_methods/write.rb Thanks for pointing out the path to ActiveRecord, I haven't gotten use to browsing source code, this is really helpful! > > Also see define_read_method in attribute_methods/read.rb, and > method_missing in base.rb (this defines finder methods dynamically) cool I will do that =) -- Kind Regards, Rajinder Yadav http://DevMentor.org Do Good! - Share Freely |