Rails：使用与validation中的模型无关的表单字段
在Ruby on Rails应用程序中，我尝试使用来自validation中与模型无关的字段的信息。
这是模型的一部分作为一个例子（整个模型有点大）：
class Scorecard < ActiveRecord::Base belongs_to :course belongs_to :user validate :attributes_consistency def attributes_consistency # Executed for all scorecards. Checks if the user completed the hole attributes correctly if ( params[:no_fairways] and any_fairways? and !only_nine? ) or ( params[:no_fairways] and !any_h1_to_h9_score_blank and any_h1_to_h9_fairway? and only_nine? ) or ( params[:no_fairways] and !any_h10_to_h18_score_blank and any_h10_to_h18_fairway? and only_nine? ) errors.add_to_base("You inidicated that you missed all the fairways, but you also marked one or more fairways in the scorecard. Either uncheck the fairways mistakenly marked or uncheck the 'No fairways' checkbox.") end if ( params[:no_girs] and any_girs? and !only_nine? ) or ( params[:no_girs] and !any_h1_to_h9_score_blank and any_h1_to_h9_gir? and only_nine? ) or ( params[:no_girs] and !any_h10_to_h18_score_blank and any_h10_to_h18_gir? and only_nine? ) errors.add_to_base("You inidicated that you missed all the greens, but you also marked one or more greens in the scorecard. Either uncheck the marked greens on the scorecard or uncheck the 'No GIRs' checkbox.") end end # attributes_consistency def any_h1_to_h9_score_blank? h1_score.blank? or h2_score.blank? or h3_score.blank? or h4_score.blank? or h5_score.blank? or h6_score.blank? or h7_score.blank? or h8_score.blank? or h9_score.blank? end def any_h10_to_h18_score_blank? h10_score.blank? or h11_score.blank? or h12_score.blank? or h13_score.blank? or h14_score.blank? or h15_score.blank? or h16_score.blank? or h17_score.blank? or h18_score.blank? end def any_h1_to_h9_fairway? h1_fairway? or h2_fairway? or h3_fairway? or h4_fairway? or h5_fairway? or h6_fairway? or h7_fairway? or h8_fairway? or h9_fairway? end def any_h10_to_h18_fairway? h10_fairway? or h11_fairway? or h12_fairway? or h13_fairway? or h14_fairway? or h15_fairway? or h16_fairway? or h17_fairway? or h18_fairway? end def any_h1_to_h9_gir? h1_gir? or h2_gir? or h3_gir? or h4_gir? or h5_gir? or h6_gir? or h7_gir? or h8_gir? or h9_gir? end def any_h10_to_h18_gir? h10_gir? or h11_gir? or h12_gir? or h13_gir? or h14_gir? or h15_gir? or h16_gir? or h17_gir? or h18_gir? end 那么如何从模型中访问params ？
不要让params潜入模特。 在这种情况下，没有控制器。 相反，请从Railscasts查看此剧集，其中讨论的虚拟属性不会进入数据库，但仍可用于validation。
您不需要虚拟属性的相应模型属性。 定义类的本地属性，例如保存状态的@no_fairways 。
class ScoreCard < ActiveRecord::Base # define attributes and accessors for both fields attr_accessor :no_fairways, :no_girs .. end
现在你在里面形成，你可以写：
<% form_for @scorecard %> <%= f.check_box :no_fairways %> <% end %>
找到解决方案，感谢语言，“虚拟属性”帮助谷歌搜索。
实现此目的的最简洁方法是创建不属于数据库但仍属于模型的属性。 在我的情况下，我把它放入模型：
attr_accessor :no_fairways attr_accessor :no_girs
那简单！ 现在@scorecard.no_fairways和@scorecard.no_girs就像任何其他属性一样，但不是数据库的一部分。