未定义的方法new_record？为nil：NilClass

这是我的部分是抛出错误：

<div class="nested-fields">
  <div>
    <%= f.input :address1 %>
  </div>
  <div>
    <%= f.input :address2 %>
  </div>
  <div>
    <%= f.input :city %>
  </div>
  <div>
    <%= f.input :state %>
  </div>
  <div>
    <%= f.input :postal %>
  </div>
  <div>
    <%= link_to_remove_association "remove task",f %>
  </div>
</div>

这是调用部分的视图：

<%= simple_form_for @vendor,url: wizard_path do |f| %>
    <div id="locations">
      <%= f.simple_fields_for :locations do |location| %>
        <%= render 'location_fields',:f => location %>
      <% end %>
      <div class="links">
        <%= link_to_add_association 'add location',f,:locations %>
      </div>
    </div>

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

这是调用视图的控制器动作：

class UserStepsController < ApplicationController
  include Wicked::Wizard

  steps :personal,:locations

  def show
    @vendor = current_vendor_user.vendor
    @vendor.locations.build
    render_wizard
  end

Incase它有帮助,这里是茧中的功能,抛出错误：

def link_to_remove_association(*args,&block)
  if block_given?
    f            = args.first
    html_options = args.second || {}
    name         = capture(&block)
    link_to_remove_association(name,html_options)
  else
    name         = args[0]
    f            = args[1]
    html_options = args[2] || {}

    **is_dynamic = f.object.new_record?**
    html_options[:class] = [html_options[:class],"remove_fields #{is_dynamic ? 'dynamic' : 'existing'}"].compact.join(' ')
    hidden_field_tag("#{f.object_name}[_destroy]") + link_to(name,'#',html_options)
  end
end