Question

我在实施carrierwave时出现以下错误，以便上传图片

gem'carrierwave'，'〜＆gt; 1.0' Rails 5.0.1 ruby 2.3.3p222（2016-11-21修订版56859）[i386-mingw32]

我的模特：

class Company < ApplicationRecord

  mount_uploader :cover, CompanyAvatarUploader
  attr_accessor :cover

My CompanyAvatarUploader

   class CompanyAvatarUploader < CarrierWave::Uploader::Base

    storage :file
    def store_dir
       "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
    end
       def extension_whitelist
     %w(jpg jpeg gif png)
   end
   end

我的company_controller.erb

class CompanyController < ApplicationController

   def create

       @company = Company.new(company_params)

       respond_to do |format|

         if @company.save
           format.html { redirect_to @company, notice: 'Company saved...'}
           format.json { render :show, status: :created, location: @company}
         else
           format.html { render new}
           format.json { render json: @company.errors, status: :unprocessable_entity }

         end
private

def company_params
    params.require(:company).permit(:name, :address, :country, :telephone, :cover)
  end

end

我的new.html.erb

<p>
  <%= f.label :country %><br>
  <%= f.text_area :country %>
</p>


<p>
  <%= f.label :cover %><br>
  <%= f.file_field :cover %>
</p>

我的show.html.erb

<p>
  <strong>Country:</strong>
  <%= @company.country %>
</p>
<p>
  <%=    image_tag @company.cover.url  %>
</p>

当我尝试添加带有封面的新公司时，我遇到以下错误：

NoMethodError in Company#show
Showing 

app/views/company/show.html.erb where line #22 raised:

undefined method `url' for nil:NilClass
Extracted source (around line #22):


</p>
<p>
  <%=    image_tag @company.cover.url %>
</p>

公司信息存储在我的MySQL中但不是封面

感谢您的帮助

carrierwave undefined方法`url'代表nil：NilClass

0 个答案: