Ruby on rails 在Rails 4中使用has_至的多态类别

我只是在学习Rails，在为事件和用户配置文件分配样式（类别）时遇到了困难。风格是瑜伽的一种类型，设置为多态性，这样我就可以有活动、老师或这种风格的爱好者

在事件窗体上，字段呈现但不保存到数据库。我正在尝试使用集合_select助手，可以进行多种选择。表单提交并创建事件，但不会将任何内容保存到“样式”表中。这是建立多态关联的正确方法吗

Style.rb

 has_many :stylings, :dependent => :destroy
 has_many :events, :through => :stylings, :source => :styleable, :source_type => 'Event'
 has_many :profiles, :through => :stylings, :source => :styleable, :source_type => 'Profile'
 has_many :users, :through => :stylings, :source => :styleable, :source_type => 'User'

 belongs_to :styleable, :polymorphic => true
 belongs_to :style

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 <%= f.label :stylings, :value => 'Styles', class: 'o-label--quiet', :required => true %>
 <%= collection_select(:event, :stylings, Style.all, :id, :name, {:prompt=> 'Select style(s)'}, {:multiple => true, :class=>'o-input--quiet js-styles'}) %>

def new
  @event = Event.new
  @locations = Location.all
  @teachers = Profile.all
  @styles = Style.all
end

def create
  @event = current_user.events.build(event_params)
  @event.length = @event.end_time - @event.start_time
  @event.location_id = @event.location.id
  if @event.save
    redirect_to event_path(@event)
  else
    render 'new'
  end    
end

def edit
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
end

def update
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
  if @event.update(event_params)
    redirect_to event_path(@event)
  else
    render 'edit'
  end
end

private 

  def event_params
    params.require(:event).permit(:name, :image, :description, :start_date, :end_date, :start_time, :end_time, :all_day, :repeat, :category, :length, :link, :location_id, :user_id, :stylings => [])
  end

样式设置.rb

 has_many :stylings, :dependent => :destroy
 has_many :events, :through => :stylings, :source => :styleable, :source_type => 'Event'
 has_many :profiles, :through => :stylings, :source => :styleable, :source_type => 'Profile'
 has_many :users, :through => :stylings, :source => :styleable, :source_type => 'User'

 belongs_to :styleable, :polymorphic => true
 belongs_to :style

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 <%= f.label :stylings, :value => 'Styles', class: 'o-label--quiet', :required => true %>
 <%= collection_select(:event, :stylings, Style.all, :id, :name, {:prompt=> 'Select style(s)'}, {:multiple => true, :class=>'o-input--quiet js-styles'}) %>

def new
  @event = Event.new
  @locations = Location.all
  @teachers = Profile.all
  @styles = Style.all
end

def create
  @event = current_user.events.build(event_params)
  @event.length = @event.end_time - @event.start_time
  @event.location_id = @event.location.id
  if @event.save
    redirect_to event_path(@event)
  else
    render 'new'
  end    
end

def edit
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
end

def update
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
  if @event.update(event_params)
    redirect_to event_path(@event)
  else
    render 'edit'
  end
end

private 

  def event_params
    params.require(:event).permit(:name, :image, :description, :start_date, :end_date, :start_time, :end_time, :all_day, :repeat, :category, :length, :link, :location_id, :user_id, :stylings => [])
  end

Event.rb

 has_many :stylings, :dependent => :destroy
 has_many :events, :through => :stylings, :source => :styleable, :source_type => 'Event'
 has_many :profiles, :through => :stylings, :source => :styleable, :source_type => 'Profile'
 has_many :users, :through => :stylings, :source => :styleable, :source_type => 'User'

 belongs_to :styleable, :polymorphic => true
 belongs_to :style

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 <%= f.label :stylings, :value => 'Styles', class: 'o-label--quiet', :required => true %>
 <%= collection_select(:event, :stylings, Style.all, :id, :name, {:prompt=> 'Select style(s)'}, {:multiple => true, :class=>'o-input--quiet js-styles'}) %>

def new
  @event = Event.new
  @locations = Location.all
  @teachers = Profile.all
  @styles = Style.all
end

def create
  @event = current_user.events.build(event_params)
  @event.length = @event.end_time - @event.start_time
  @event.location_id = @event.location.id
  if @event.save
    redirect_to event_path(@event)
  else
    render 'new'
  end    
end

def edit
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
end

def update
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
  if @event.update(event_params)
    redirect_to event_path(@event)
  else
    render 'edit'
  end
end

private 

  def event_params
    params.require(:event).permit(:name, :image, :description, :start_date, :end_date, :start_time, :end_time, :all_day, :repeat, :category, :length, :link, :location_id, :user_id, :stylings => [])
  end

Profile.rb

 has_many :stylings, :dependent => :destroy
 has_many :events, :through => :stylings, :source => :styleable, :source_type => 'Event'
 has_many :profiles, :through => :stylings, :source => :styleable, :source_type => 'Profile'
 has_many :users, :through => :stylings, :source => :styleable, :source_type => 'User'

 belongs_to :styleable, :polymorphic => true
 belongs_to :style

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 <%= f.label :stylings, :value => 'Styles', class: 'o-label--quiet', :required => true %>
 <%= collection_select(:event, :stylings, Style.all, :id, :name, {:prompt=> 'Select style(s)'}, {:multiple => true, :class=>'o-input--quiet js-styles'}) %>

def new
  @event = Event.new
  @locations = Location.all
  @teachers = Profile.all
  @styles = Style.all
end

def create
  @event = current_user.events.build(event_params)
  @event.length = @event.end_time - @event.start_time
  @event.location_id = @event.location.id
  if @event.save
    redirect_to event_path(@event)
  else
    render 'new'
  end    
end

def edit
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
end

def update
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
  if @event.update(event_params)
    redirect_to event_path(@event)
  else
    render 'edit'
  end
end

private 

  def event_params
    params.require(:event).permit(:name, :image, :description, :start_date, :end_date, :start_time, :end_time, :all_day, :repeat, :category, :length, :link, :location_id, :user_id, :stylings => [])
  end

events/_form.html.erb

 has_many :stylings, :dependent => :destroy
 has_many :events, :through => :stylings, :source => :styleable, :source_type => 'Event'
 has_many :profiles, :through => :stylings, :source => :styleable, :source_type => 'Profile'
 has_many :users, :through => :stylings, :source => :styleable, :source_type => 'User'

 belongs_to :styleable, :polymorphic => true
 belongs_to :style

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 has_many :stylings, :as => :styleable, :dependent => :destroy
 has_many :styles, through: :stylings

 <%= f.label :stylings, :value => 'Styles', class: 'o-label--quiet', :required => true %>
 <%= collection_select(:event, :stylings, Style.all, :id, :name, {:prompt=> 'Select style(s)'}, {:multiple => true, :class=>'o-input--quiet js-styles'}) %>

def new
  @event = Event.new
  @locations = Location.all
  @teachers = Profile.all
  @styles = Style.all
end

def create
  @event = current_user.events.build(event_params)
  @event.length = @event.end_time - @event.start_time
  @event.location_id = @event.location.id
  if @event.save
    redirect_to event_path(@event)
  else
    render 'new'
  end    
end

def edit
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
end

def update
  @event = Event.find(params[:id])
  @locations = Location.all
  @users = User.all
  @teachers = Profile.all
  @styles = Style.all
  if @event.update(event_params)
    redirect_to event_path(@event)
  else
    render 'edit'
  end
end

private 

  def event_params
    params.require(:event).permit(:name, :image, :description, :start_date, :end_date, :start_time, :end_time, :all_day, :repeat, :category, :length, :link, :location_id, :user_id, :stylings => [])
  end

schema.rb

create_table "stylings", force: :cascade do |t|
  t.integer  "style_id"
  t.integer  "styleable_id"
  t.string   "styleable_type"
  t.datetime "created_at",     null: false
  t.datetime "updated_at",     null: false
end

检查日志（在开发中，

log/development.log

）。它们是否显示所传递的正确参数？它们是否显示由强参数过滤掉的任何参数？有验证错误吗？您的

事件

模型中是否有

接受\u嵌套的\u属性\u用于：样式

？我的直觉是你的

事件参数
也需要更改
：styleings=>[]
为
：styleings=>[:id]
。啊，他们说“unpermitted parameter:styleings”添加这两个参数（
接受嵌套的属性\u用于：styleings
和
：styleings=>[:id]
）生成EventsController中的NoMethodError#为nil:NilClass创建未定义的方法'each'
-再次删除：id，我回到以前的状态，日志显示
“事件”=>{“名称”=>“接受参数”、“类别”=>“认证”、“样式”=>“2”…
，但仍然
未允许的参数：样式