In Rails 3.1 you can just

class Form < ActiveRecord::Base  serialize :column, JSONend

Hope that helps

In Rails 3.1 you can use custom coders with serialize.

class ColorCoder  # Called to deserialize data to ruby object.  def load(data)  end  # Called to convert from ruby object to serialized data.  def dump(obj)  endendclass Fruits < ActiveRecord::Base  serialize :color, ColorCoder.newend

Hope this helps.

References:

Definition of serialize:https://github.com/rails/rails/blob/master/activerecord/lib/active_record/base.rb#L556

The default YAML coder that ships with rails:https://github.com/rails/rails/blob/master/activerecord/lib/active_record/coders/yaml_column.rb

And this is where the call to the load happens:https://github.com/rails/rails/blob/master/activerecord/lib/active_record/attribute_methods/read.rb#L132

Update

See mid's high rated answer below for a much more appropriate Rails >= 3.1 answer. This is a great answer for Rails < 3.1.

Probably this is what you're looking for.

Form.find(:first).to_json

Update

1) Install 'json' gem:

gem install json

2) Create JsonWrapper class

# lib/json_wrapper.rbrequire 'json'class JsonWrapper  def initialize(attribute)    @attribute = attribute.to_s  end  def before_save(record)    record.send("#{@attribute}=", JsonWrapper.encrypt(record.send("#{@attribute}")))  end  def after_save(record)    record.send("#{@attribute}=", JsonWrapper.decrypt(record.send("#{@attribute}")))  end  def self.encrypt(value)    value.to_json  end  def self.decrypt(value)    JSON.parse(value) rescue value  endend

3) Add model callbacks:

#app/models/user.rbclass User < ActiveRecord::Base    before_save      JsonWrapper.new( :name )    after_save       JsonWrapper.new( :name )    def after_find      self.name = JsonWrapper.decrypt self.name    endend

4) Test it!

User.create :name => {"a"=>"b", "c"=>["d", "e"]}

PS:

It's not quite DRY, but I did my best. If anyone can fix after_find in User model, it'll be great.