商品修改頁也能修替換圖片

app/controllers/admin/products_controller.rb

@@ -14,6 +14,12 @@ def new
 
   def edit
     @product = Product.find(params[:id])
+
+    if @product.photo.present?
+       @photo = @product.photo
+     else
+       @photo = @product.build_photo
+     end
   end
 
   def create

app/views/admin/products/edit.html.erb

@@ -16,6 +16,17 @@
     <%= f.input :price %>
   </div>
 
+  <% if @photo.image.present? %>
+    <span>目前商品圖</span> <br>
+    <%= image_tag(@photo.image.thumb.url) %>
+  <% end %>
+
+  <div class="form-group">
+    <%= f.simple_fields_for :photo do |c| %>
+      <%= c.input :image , as: :file %>
+    <% end %>
+  </div>
+
   <%= f.submit "Submit", data: { disable_with: "Submitting..." } %>
 
 <% end %>