无法提交添加操作表单- Rails 4

Question

所以我的问题大致如下。我有一个具有以下类的rails应用程序：

• 用户
• 技能

每个用户都可以拥有多种技能，它们是从用户配置文件屏幕中添加的，这是用户控制器的显示操作。目前，我有技能设置和能够被创建，但我不能添加一个预先构建的技能到用户配置文件。当我尝试提交时，我得到以下错误Empty list of attributes to change

以下是我对用户操作的添加技巧：

def add_skill_to_user
    user = User.find(params[:id])
    user.skills.create(skill_params) #skill name, level...
    @skills_options = Skill.all.map{|s| [ s.name, s.id] }
    #whatever happens when this is is done, redirect, json answer etc...
    if user.skills.update_all(skill_params)
      flash[:success] = "Skill Added"
    else
       render 'add_skill_to_user'
    end
  end

  private
    # Set skills params whitelist    
    def skill_params
      params.permit(:name, :user_id)
    end    

和下面的路线

post 'users/:id/add_skill_to_user' => 'users#add_skill_to_user'

这是我的表格

<%= form_tag({controller: "users", action: "add_skill_to_user"}, method: "put") do %>
    <%= collection_select(:skill, :name, Skill.all, :id, :name) %>
    <%= submit_tag 'Submit' %>
<%end%>

请告诉我您需要的任何其他信息。

User.rb

class User < ActiveRecord::Base
    attr_accessor :remember_token, :activation_token, :reset_token
    before_save   :downcase_email
    before_create :create_activation_digest

    belongs_to :group
    has_many :ranks
    has_many :skills
    has_many :mission_notes
    has_and_belongs_to_many :training_events
    accepts_nested_attributes_for :skills

    validates :username, presence: true
    validates :email, presence: true
    VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
    validates :email, presence: true, length: { maximum: 255 },
                    format: { with: VALID_EMAIL_REGEX },
                    uniqueness: { case_sensitive: false }
    validates :group_id, presence: true
    has_secure_password
    validates :password, length: { minimum: 6 }, allow_blank: true

    # Returns the hash digest of the given string.
    def User.digest(string)
        cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
                                                      BCrypt::Engine.cost
        BCrypt::Password.create(string, cost: cost)
    end

    # Returns a random token.
    def User.new_token
        SecureRandom.urlsafe_base64
    end

    # Remembers a user in the database for use in persistent sessions.
    def remember
        self.remember_token = User.new_token
        update_attribute(:remember_digest, User.digest(remember_token))
    end

    # Returns true if the given token matches the digest.
    def authenticated?(remember_token)
        return false if remember_digest.nil?
        BCrypt::Password.new(remember_digest).is_password?(remember_token)
    end

    # Forgets a user.
    def forget
        update_attribute(:remember_digest, nil)
    end

    # Converts email to all lower-case.
    def downcase_email
      self.email = email.downcase
    end

    # Creates and assigns the activation token and digest.
    def create_activation_digest
      self.activation_token  = User.new_token
      self.activation_digest = User.digest(activation_token)
    end

    # Returns true if the given token matches the digest.
    def authenticated?(attribute, token)
        digest = send("#{attribute}_digest")
        return false if digest.nil?
        BCrypt::Password.new(digest).is_password?(token)
    end

    # Activates an account.
      def activate
        update_attribute(:activated,    true)
        update_attribute(:activated_at, Time.zone.now)
      end

      # Sends activation email.
      def send_activation_email
        UserMailer.account_activation(self).deliver
      end

      # Sets the password reset attributes.
  def create_reset_digest
    self.reset_token = User.new_token
    update_attribute(:reset_digest,  User.digest(reset_token))
    update_attribute(:reset_sent_at, Time.zone.now)
  end

  # Sends password reset email.
  def send_password_reset_email
    UserMailer.password_reset(self).deliver
  end

  def password_reset_expired?
    reset_sent_at < 2.hours.ago
  end


end

Skill.rb

class Skill < ActiveRecord::Base
    belongs_to :user
end

Answer 1

您的collection_select将生成类似于

<select name="skill[name]">
  <option value="1">First Skill</option>
  ...
</select>

其中"skill[name]"没有反映选项值中的内容(技能ids)。

此外，params白名单并不处理由select生成的POST数据是一个数组这一事实。

我建议

<%= collection_select(:skill, :id, Skill.all, :id, :name) %>

在控制器中使用此白名单筛选器：

params.require(:skill).permit(:id)

但是您的add_skill_to_user方法令人困惑。如果您想要做的只是将预先存在的技能分配给用户，这有一个RailsCast。