Rails 5.2:ActionController:：EventsController中的参数缺失#用于嵌套资源的新功能

我正在尝试创建时间线，每个时间线由多个事件组成。我在“视图”文件夹的“时间线”中嵌套了事件

显示页面以创建新事件时，返回以下错误：

我的事件控制器

    class EventsController < ApplicationController
    before_action :get_timeline
    before_action :set_event, only: [:show, :edit, :update, :destroy]

  # GET /events
  # GET /events.json
  def index
    @events = @timeline.events
  end

  # GET /events/1
  # GET /events/1.json
  def show
  end

  # GET /events/new
  def new
    @event = @timeline.events.create(event_params)
  end

  # GET /events/1/edit
  def edit
  end

  # POST /events
  # POST /events.json
  def create
    @event = Event.new

    respond_to do |format|
      if @event.save
        format.html { redirect_to @event, notice: 'Event was successfully created.' }
        format.json { render :show, status: :created, location: @event }
      else
        format.html { render :new }
        format.json { render json: @event.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /events/1
  # PATCH/PUT /events/1.json
  def update
    respond_to do |format|
      if @event.update(event_params)
        format.html { redirect_to @event, notice: 'Event was successfully updated.' }
        format.json { render :show, status: :ok, location: @event }
      else
        format.html { render :edit }
        format.json { render json: @event.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /events/1
  # DELETE /events/1.json
  def destroy
    @event.destroy
    respond_to do |format|
      format.html { redirect_to events_url, notice: 'Event was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
        def get_timeline
            @timeline = Timeline.find(params[:timeline_id])
        end

        # Use callbacks to share common setup or constraints between actions.
    def set_event
      @event = @timeline.events.find(params[:id])
    end

    # Only allow a list of trusted parameters through.
    def event_params
      params.require(:event).permit(:name, :description, :timeline_id)
    end
end

类事件控制器

我的活动表

    <%= form_with(model: [@timeline, event], local: true) do |form| %>
  <% if event.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(event.errors.count, "error") %> prohibited this event from being saved:</h2>

      <ul>
      <% event.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= form.label :timeline %>
    <%= collection_select( :timeline, :timeline_id, Timeline.all, :id, :name, { multiple: false } ) %>
  </div>

  <div class="field">
    <%= form.label :name %>
    <%= form.text_field :name %>
  </div>

  <div class="field">
    <%= form.label :description %>
    <%= form.text_area :description %>
  </div>

  <div class="actions">
    <%= form.submit %>
  </div>
<% end %>

禁止保存此事件：

我忽略了什么

    class EventsController < ApplicationController
    before_action :get_timeline
    before_action :set_event, only: [:show, :edit, :update, :destroy]

  # GET /events
  # GET /events.json
  def index
    @events = @timeline.events
  end

  # GET /events/1
  # GET /events/1.json
  def show
  end

  # GET /events/new
  def new
    @event = @timeline.events.create(event_params)
  end

  # GET /events/1/edit
  def edit
  end

  # POST /events
  # POST /events.json
  def create
    @event = Event.new

    respond_to do |format|
      if @event.save
        format.html { redirect_to @event, notice: 'Event was successfully created.' }
        format.json { render :show, status: :created, location: @event }
      else
        format.html { render :new }
        format.json { render json: @event.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /events/1
  # PATCH/PUT /events/1.json
  def update
    respond_to do |format|
      if @event.update(event_params)
        format.html { redirect_to @event, notice: 'Event was successfully updated.' }
        format.json { render :show, status: :ok, location: @event }
      else
        format.html { render :edit }
        format.json { render json: @event.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /events/1
  # DELETE /events/1.json
  def destroy
    @event.destroy
    respond_to do |format|
      format.html { redirect_to events_url, notice: 'Event was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
        def get_timeline
            @timeline = Timeline.find(params[:timeline_id])
        end

        # Use callbacks to share common setup or constraints between actions.
    def set_event
      @event = @timeline.events.find(params[:id])
    end

    # Only allow a list of trusted parameters through.
    def event_params
      params.require(:event).permit(:name, :description, :timeline_id)
    end
end

    <%= form_with(model: [@timeline, event], local: true) do |form| %>
  <% if event.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(event.errors.count, "error") %> prohibited this event from being saved:</h2>

      <ul>
      <% event.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= form.label :timeline %>
    <%= collection_select( :timeline, :timeline_id, Timeline.all, :id, :name, { multiple: false } ) %>
  </div>

  <div class="field">
    <%= form.label :name %>
    <%= form.text_field :name %>
  </div>

  <div class="field">
    <%= form.label :description %>
    <%= form.text_area :description %>
  </div>

  <div class="actions">
    <%= form.submit %>
  </div>
<% end %>