pry.rb

[20] pry(main)> class Foo < ActiveRecord::Base
[20] pry(main)* end  
=> nil
[21] pry(main)> f = Foo.new phone_numbers: {"dario" => "12345"}
=> #<Foo:0x007fc69ba76228 id: nil, name: nil, phone_numbers: "{\"dario\"=>\"12345\"}", created_at: nil, updated_at: nil>
[22] pry(main)> f.phone_numbers.class
=> String
[23] pry(main)> class Foo < ActiveRecord::Base
[23] pry(main)*   serialize :phone_numbers
[23] pry(main)* end  
=> #<ActiveRecord::AttributeDecorators::TypeDecorator:0x007fc69dbba768
 @decorations=
  {"_time_zone_conversion"=>
    [#<Proc:0x007fc6a009b4b0@/Users/jk/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-4.2.0/lib/active_record/attribute_methods/time_zone_conversion.rb:49 (lambda)>,
     #<Proc:0x007fc6a009b3c0@/Users/jk/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-4.2.0/lib/active_record/attribute_methods/time_zone_conversion.rb:50>],
   "_optimistic_locking"=>
    [#<Proc:0x007fc6a00992a0@/Users/jk/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-4.2.0/lib/active_record/locking/optimistic.rb:174 (lambda)>,
     #<Proc:0x007fc6a00991b0@/Users/jk/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-4.2.0/lib/active_record/locking/optimistic.rb:175>],
   "_phone_numbers_serialize"=>
    [#<Proc:0x007fc69dbbaf38@/Users/jk/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-4.2.0/lib/active_record/attribute_decorators.rb:12 (lambda)>,
     #<Proc:0x007fc69dbbaf88@/Users/jk/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-4.2.0/lib/active_record/attribute_methods/serialization.rb:50>]}>
[24] pry(main)> f = Foo.new phone_numbers: {"dario" => "12345"}
=> #<Foo:0x007fc69db700c8 id: nil, name: nil, phone_numbers: {"dario"=>"12345"}, created_at: nil, updated_at: nil>
[25] pry(main)> f.phone_numbers.class
=> Hash