Ruby:未定义的方法'<<'，用于模型上的nil:NilClass

Question

我已经在这个上面呆了几天了。 任何帮助将不胜感激。 对于以下代码，我不断收到此 nomethoderror ：

band.rb（错误显然是@booked_gigs <<set.gig）

  def booked_gigs
    @booked_gig = []
    hired_gigs = self.bandlists.filled
    hired_gigs.each do |set|
     if set.gig.date >= Date.today
      @booked_gigs << set.gig
     end
    end
  end

_booked.html.erb：

<% @booked.each do |booked| %>
  <%= render "shared/gig_full", gig: booked %>
<% end %>

dashboard_controller.rb：

class DashboardController < ApplicationController
  before_filter :authenticate_user!, only: [:dashboard]
  def dashboard
    if current_user.role == "venue"
      set_venue_dash
      render "venue_dashboard"
    elsif current_user.role == "musician"
      set_band_dash
      if @band.nil?
        redirect_to new_band_path
      else
        set_band_session
        set_booked_gig
        set_applied_gig
        render "band_dashboard"
      end
    else
      set_fan_dash
      render "fan_dashboard"
    end
  end
  def settings
  end
  private
    def set_venue_dash
      @venue = current_user.venues.first
    end
    def  set_band_dash
      @band = current_user.bands.first
    end
    def set_band_session
      session[:current_band_id] ||= @band.id
      @openings = @band.available_gigs
    end
    def set_booked_gig
      @booked = current_band.booked_gigs
    end
    def set_applied_gig
      @applied = current_band.applied_gigs
    end
    def set_fan_dash
      @fan = current_user.fan
    end
end

Answer 1

检查变量名称。初始化@booked_gig = []（单数），但随后尝试将项添加到@booked_gigs（复数）。

此外，您可能希望在方法末尾返回@booked_gigs，否则它将返回hired_gigs的内容（无论您的each块中的内容如何）

def booked_gigs
  @booked_gigs = []
  hired_gigs = self.bandlists.filled
  hired_gigs.each do |set|
    if set.gig.date >= Date.today
      @booked_gigs << set.gig
    end
  end
  @booked_gigs
end