YAML 대신 JSON을 사용하여 ActiveRecord 직렬화

YAML 대신 JSON을 사용하여 ActiveRecord 직렬화

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직렬화 된 열을 사용하는 모델이 있습니다.

class Form < ActiveRecord::Base
  serialize :options, Hash
end

이 직렬화가 YAML 대신 JSON을 사용하도록하는 방법이 있습니까?

---

Rails 3.1에서는

class Form < ActiveRecord::Base
  serialize :column, JSON
end

도움이되는 희망

---

Rails 3.1에서는 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)
  end
end

class Fruits < ActiveRecord::Base
  serialize :color, ColorCoder.new
end

도움이 되었기를 바랍니다.

참조 :

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

레일과 함께 제공되는 기본 YAML 코더 : https://github.com/rails/rails/blob/master/activerecord/lib/active_record/coders/yaml_column.rb

그리고 여기에서 호출이 load발생합니다 : https://github.com/rails/rails/blob/master/activerecord/lib/active_record/attribute_methods/read.rb#L132

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최신 정보

훨씬 더 적절한 Rails> = 3.1 답변은 아래 mid의 높은 등급 답변을 참조하십시오. 이것은 Rails <3.1에 대한 훌륭한 답변입니다.

아마도 이것은 당신이 찾고있는 것입니다.

Form.find(:first).to_json

최신 정보

1) 'JSON'설치 보석 :

gem install json

2) JsonWrapper 클래스 생성

# lib/json_wrapper.rb

require '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
  end
end

3) 모델 콜백 추가 :

#app/models/user.rb

class User < ActiveRecord::Base
    before_save      JsonWrapper.new( :name )
    after_save       JsonWrapper.new( :name )

    def after_find
      self.name = JsonWrapper.decrypt self.name
    end
end

4) 테스트 해보세요!

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

추신:

꽤 건조하지는 않지만 최선을 다했습니다. 누구든지 해결할 수있는 경우 after_find에 User모델이 좋을 것이다.

---

내 요구 사항은이 단계에서 코드를 많이 재사용 할 필요가 없었기 때문에 증류 된 코드는 위의 답변의 변형입니다.

  require "json/ext"

  before_save :json_serialize  
  after_save  :json_deserialize


  def json_serialize    
    self.options = self.options.to_json
  end

  def json_deserialize    
    self.options = JSON.parse(options)
  end

  def after_find 
    json_deserialize        
  end  

건배, 결국 아주 쉽습니다!

---

기본값을 사용하는 자체 YAML 코더를 작성했습니다. 수업은 다음과 같습니다.

class JSONColumn
  def initialize(default={})
    @default = default
  end

  # this might be the database default and we should plan for empty strings or nils
  def load(s)
    s.present? ? JSON.load(s) : @default.clone
  end

  # this should only be nil or an object that serializes to JSON (like a hash or array)
  def dump(o)
    JSON.dump(o || @default)
  end
end

이후 load와 dump인스턴스 메소드는 그 두 번째 인수로서 전달 될 필요 인스턴스 serialize모델을 정의. 다음은 그 예입니다.

class Person < ActiveRecord::Base
  validate :name, :pets, :presence => true
  serialize :pets, JSONColumn.new([])
end

I tried creating a new instance, loading an instance, and dumping an instance in IRB, and it all seemed to work properly. I wrote a blog post about it, too.

---

The serialize :attr, JSON using composed_of method works like this:

  composed_of :auth,
              :class_name => 'ActiveSupport::JSON',
              :mapping => %w(url to_json),
              :constructor => Proc.new { |url| ActiveSupport::JSON.decode(url) }

where url is the attribute to be serialized using json and auth is the new method available on your model that saves its value in json format to the url attribute. (not fully tested yet but seems to be working)

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A simpler solution is to use composed_of as described in this blog post by Michael Rykov. I like this solution because it requires the use of fewer callbacks.

Here is the gist of it:

composed_of :settings, :class_name => 'Settings', :mapping => %w(settings to_json),
                       :constructor => Settings.method(:from_json),
                       :converter   => Settings.method(:from_json)

after_validation do |u|
  u.settings = u.settings if u.settings.dirty? # Force to serialize
end

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Aleran, have you used this method with Rails 3? I've somewhat got the same issue and I was heading towards serialized when I ran into this post by Michael Rykov, but commenting on his blog is not possible, or at least on that post. To my understanding he is saying that you do not need to define Settings class, however when I try this it keeps telling me that Setting is not defined. So I was just wondering if you have used it and what more should have been described? Thanks.

ReferenceURL : https://stackoverflow.com/questions/2080347/activerecord-serialize-using-json-instead-of-yaml