多态关联表单-创建新的或编辑现有的

Question

I have a polymorphic association set up for images on companies. I want to allow for up to 6 images to a company. If an image has already been created, that should display that image, if not, it should be an upload field.

Model set up:

class Company < ApplicationRecord
   has_many :images, as: :imageable
   accepts_nested_attributes_for :images
end

Controller set up:

def details
   images_count = @company.images.count
   build_number = 6 - images_count
   build_number.times { @company.images.build }
end

In the view:

<%= form_for(@company) do |f| %>
   <%= f.fields_for :images,  multipart: true do |g| %>
      <%= g.file_field :image %>
   <% end %>
<% end %>

Is it possible to check to see if that particular instance of image is already created, and then display that image? As it is currently created, it will use the file_field for all 6 instances.

Answer 1

在循环内部，您可以检查对象是否持久

<%= form_for(@company) do |f| %> <%= f.fields_for :images, multipart: true do |g| %> <% if g.object.persisted? %> --- DISPLAY IMAGE <% else %> <%= g.file_field :image %> <% end %> <% end %> <% end %