ruby-on-rails – 数据模型的动态自定义字段

每个模型都会参考某个项目,其中包含有关字段的信息

IE：

class Project < ActiveRecord::Base
  has_many :project_fields
  has_many :string_datas :through => project_fields
  has_many :file_datas :through => project_fields
  has_many :boolean_datas :through => project_fields
  etc ...
end

class ProjectField < ActiveRecord::Base
  # title:string field_type:string project_id:integer name:string
  belongs_to :project
  has_many :string_datas
  has_many :file_datas
  has_many :boolean_datas
  etc ...
end

class StringData < ActiveRecord::Base
  # data:string project_field_id:integer
  belongs_to :project_field,:conditions => { :field_type => 'String' }
end

class FileData < ActiveRecord::Base
  # data:file project_field_id:integer
  belongs_to :project_field,:conditions => { :field_type => 'File' }
end

project = Project.new
project.project_fields.new(:title => "Product title",:field_type => "String",:name => 'product_title')
project.project_fields.new(:title => "Product photo",:field_type => "File",:name => 'product_photo')
project.save

<% form_for project do |f| -%>
  <% project.project_fields.each do |field| -%>
    <%= field_setter field %>
    #=> field_setter is a helper method wich creates form element (text_field,text_area,file_field etc) for each type of prject_field
    #=> ie: if field.field_type == 'String' it will return
    #=> text_field_tag field.name => <input name='product_name' />
  <% end -%>
<% end -%>

并创建(更新)方法

def create
  project = Project.new(params[:project])
  project.project_fields.each do |field|
    filed.set_field params[field.name]
    # where set_field is model method for setting value depending on field type
  end
  project.save
end

它没有经过测试和优化,只是展示了实现它的方式.

更新：我已更新代码但它只是模型,你必须认为自己有点:)你可以尝试找出另一个实现