rails未定义方法`[]'nil：NilClass关联

Question

在保存产品后立即放置关联图像后，rails为nil：NilClass吐出关于方法`[]'的原因，为什么显示为nil，制作？

def create 

    @product = current_square.products.build(params[:product]) 
    @images = @product.images.build 
    respond_to do |format| 
    format.html do 
     if @product.save 
     params[:images]['ifoto'].each do |a| 
      @images = @product.images.create!(:ifoto => a) 
     end 
     end 
    end 
    end 

end 

Answer 1

我看到它是你在这个问题上的第二个问题。 请阅读一些教程有关保存协会：

http://www.railscook.com/recipes/multiple-files-upload-with-nested-resource-using-paperclip-in-rails/

或

http://www.discretelogix.com/blog/ruby-rails/uploading-multiple-files-with-carrierwave-in-rails-4

你的方法或许应该是这样的：

def create 
    @product = current_square.products.build(params[:product]) 

    respond_to do |format| 
    format.html do 
     if @product.save 
     if params[:images] && params[:images]['ifoto'] 
      params[:images]['ifoto'].each do |foto| 
      @images = @product.images.create!(ifoto: foto) 
     end 
     end 
    end 
    end 
end