collection_check_boxes的AssociationTypeMismatch

Question

控制器

class PlayerProfilesController < InheritedResources::Base

    def show
        @player_profile = PlayerProfile.find(params[:id])
    end
end

模型

class PlayerProfile < ActiveRecord::Base

  has_many :playing_roles, :dependent => :destroy
  has_many :player_roles, through: :playing_roles

end

class PlayerRole < ActiveRecord::Base

   has_many :playing_roles, :dependent => :destroy 
   has_many :player_profiles, through: :playing_roles

end

class PlayingRole < ActiveRecord::Base
  belongs_to :player_profile
  belongs_to :player_role

end

show.html.erb

<%=collection_check_boxes(:player_profile, :playing_roles, PlayerRole.all, :id, :name)%>

collection_check_boxes（docs）

为两个复选框生成的HTML

<input id="player_profile_playing_roles_1" name="player_profile[playing_roles][]" type="checkbox" value="1" class="hidden-field">
<span class="custom checkbox checked"></span>
<label for="player_profile_playing_roles_1">Striker</label>

<input id="player_profile_playing_roles_2" name="player_profile[playing_roles][]" type="checkbox" value="2" class="hidden-field">
<span class="custom checkbox"></span>
<label for="player_profile_playing_roles_2">Midfielder</label>
<input name="player_profile[playing_roles][]" type="hidden" value="">

它似乎显示所有正确但但当我点击提交按钮时，我收到此错误：

Answer 1

对不起，我觉得这很复杂，但我认为不是。

您告诉collection_check_boxes期待:playing_roles，然后通过PlayerRole.all将其传递给PlayerRoles。那就是不匹配。 AssociationTypeMismatch是指告对象关联Duck但随后将其传递给Helicopter。

你需要这样做：

<%= collection_check_boxes(:player_profile, :player_role_ids, PlayerRole.all, :id, :name) %>

你告诉它期待:player_role_ids，你传递了一个PlayerRole.all的集合，其值为方法:id和文本方法:name。

然后，在更新中，它会将这些ID保存到Player上的player_role_ids属性，从而导致构建关联。

另见： Rails has_many :through and collection_select with multiple