dynamically define attr_accessors on objects?

[Aaron Smith]

How can I dynamically define attr_accessors on an object?

EX:;:
class Person
attr_accessor :firstname
end
p = Person.new
p.firstname = 'aaron'
p.instance_variable_set@lastname, 'smith')
puts p.inspect
puts p.firstname
puts p.lastname

the last line generates an "undefined method lastname" error..

any ideas?
thanks

 

[MenTaLguY]

How can I dynamically define attr_accessors on an object?

EX:;:
class Person
attr_accessor :firstname
end
p = Person.new
p.firstname = 'aaron'

class << p
attr_accessor :lastname
end
p.lastname = 'smith'

puts p.inspect
puts p.firstname
puts p.lastname

You have to explicitly create the accessor methods; you don't get them
automatically when setting an instance variable.

-mental

 

[Robert Klemme]

How can I dynamically define attr_accessors on an object?

EX:;:
class Person
attr_accessor :firstname
end
p = Person.new
p.firstname = 'aaron'
p.instance_variable_set@lastname, 'smith')
puts p.inspect
puts p.firstname
puts p.lastname

the last line generates an "undefined method lastname" error..

any ideas?

Use OpenStruct.

robert

 

[Phil Tomson]

How can I dynamically define attr_accessors on an object?

EX:;:
class Person
attr_accessor :firstname
end
p = Person.new
p.firstname = 'aaron'
p.instance_variable_set@lastname, 'smith')
puts p.inspect
puts p.firstname
puts p.lastname

the last line generates an "undefined method lastname" error..

any ideas?
thanks

--

I suppose you could do something like:

class Person
def def_accessor name, val=nil
self.class.class_eval { attr_accessor name.intern }
instance_variable_set ( "@#{name}".intern, val )
end
end

Then you could do something like:
h = { "fooname"=>"Foo", "age"=>28 }
h.each {|key,value| p.def_accessor key, value }


...but the other suggestion to use OpenStruct is probably a better idea.

Phil

 

[Aaron Smith]

thanks for the suggestions.. went with the openstruct.