使用 Active Storage 部分工作的简单图像上传

Question

Any help or guidance would be most appreciated.

I've followed the Rails Guide, however, and I can upload an image to a model. However, it produces an error.

I've copied what the error suggests and that produces another error and does not upload an image.

Many, many thanks in advance!

This works but produces an error post form submission. If I hit back and then visit the specific prod id product#show the image has uploaded.

Error

NameError in ProductsController#create undefined local variable or method `product' for # Did you mean? @product

Products.rb

    def create
        @list = List.find(params[:list_id])
        @product = @list.products.create(product_params)
        product.hero.attach(params[:hero])
        redirect_to list_path(@list)
    end

This does not work however, looks syntactically correct as the "@product" model attaches to the:hero.

Products.rb

    def create
        @list = List.find(params[:list_id])
        @product = @list.products.create(product_params)
        @product.hero.attach(params[:hero])
        redirect_to list_path(@list)
    end

• creates the product
• refreshes the screen back to the product list so it looks correct.
• This breaks producing two errors:

The first error on products#show

ArgumentError in Products#show Showing /Users/user/rubyonrails/shopping/app/views/products/show.html.erb where line #2 raised:

Can't resolve image into URL: to_model delegated to attachment, but the attachment is nil

Second terminal output presents the upload seems to work then something called Active Storage Purge fires up removing it?

  ActiveStorage::Blob Load (0.3ms)  SELECT "active_storage_blobs".* FROM "active_storage_blobs" WHERE "active_storage_blobs"."id" = $1 LIMIT $2  [["id", 7], ["LIMIT", 1]]
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef] Performing ActiveStorage::PurgeJob (Job ID: e9b35a62-ff6c-4a38-8946-3aa9c19668ef) from Async(active_storage_purge) enqueued at 2020-04-15T11:31:41Z with arguments: #<GlobalID:0x00007f92b1da3d60 @uri=#<URI::GID gid://shopping/ActiveStorage::Blob/7>>
[ActiveJob] [ActiveStorage::AnalyzeJob] [b724849f-6993-4130-bef1-a0f8837a3171]    (6.4ms)  COMMIT
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]    (0.8ms)  BEGIN
[ActiveJob] [ActiveStorage::AnalyzeJob] [b724849f-6993-4130-bef1-a0f8837a3171] Performed ActiveStorage::AnalyzeJob (Job ID: b724849f-6993-4130-bef1-a0f8837a3171) from Async(active_storage_analysis) in 15.88ms
Started GET "/lists/9" for ::1 at 2020-04-15 12:31:41 +0100
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]   ActiveStorage::Attachment Exists? (0.5ms)  SELECT 1 AS one FROM "active_storage_attachments" WHERE "active_storage_attachments"."blob_id" = $1 LIMIT $2  [["blob_id", 7], ["LIMIT", 1]]
Processing by ListsController#show as HTML
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]   ActiveStorage::Attachment Load (1.1ms)  SELECT "active_storage_attachments".* FROM "active_storage_attachments" WHERE "active_storage_attachments"."record_id" = $1 AND "active_storage_attachments"."record_type" = $2 AND "active_storage_attachments"."name" = $3 LIMIT $4  [["record_id", 7], ["record_type", "ActiveStorage::Blob"], ["name", "preview_image"], ["LIMIT", 1]]
  Parameters: {"id"=>"9"}
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]   ActiveStorage::Blob Destroy (1.0ms)  DELETE FROM "active_storage_blobs" WHERE "active_storage_blobs"."id" = $1  [["id", 7]]
  List Load (0.9ms)  SELECT "lists".* FROM "lists" WHERE "lists"."id" = $1 LIMIT $2  [["id", 9], ["LIMIT", 1]]
  ↳ app/controllers/lists_controller.rb:7:in `show'
  Product Load (0.2ms)  SELECT "products".* FROM "products" WHERE "products"."id" = $1 LIMIT $2  [["id", 9], ["LIMIT", 1]]
  ↳ app/controllers/lists_controller.rb:8:in `show'
  Rendering lists/show.html.erb within layouts/application
  User Load (0.3ms)  SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 1], ["LIMIT", 1]]
  ↳ app/views/lists/show.html.erb:2
  Product Exists? (0.2ms)  SELECT 1 AS one FROM "products" WHERE "products"."list_id" = $1 LIMIT $2  [["list_id", 9], ["LIMIT", 1]]
  ↳ app/views/lists/show.html.erb:5
  Product Load (0.2ms)  SELECT "products".* FROM "products" WHERE "products"."list_id" = $1  [["list_id", 9]]
  ↳ app/views/lists/show.html.erb:6
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]    (6.4ms)  COMMIT
   (0.8ms)  SELECT COUNT(*) FROM "products" WHERE "products"."list_id" = $1  [["list_id", 9]]
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]   Disk Storage (0.2ms) Deleted file from key: 31cfuow9pj6vjqhq8i479fdxf1lc
  ↳ app/controllers/application_controller.rb:5:in `product_list_size?'
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef]   Disk Storage (0.1ms) Deleted files by key prefix: variants/31cfuow9pj6vjqhq8i479fdxf1lc/
  Rendered lists/show.html.erb within layouts/application (Duration: 9.5ms | Allocations: 7278)
[ActiveJob] [ActiveStorage::PurgeJob] [e9b35a62-ff6c-4a38-8946-3aa9c19668ef] Performed ActiveStorage::PurgeJob (Job ID: e9b35a62-ff6c-4a38-8946-3aa9c19668ef) from Async(active_storage_purge) in 22.5ms
[Webpacker] Everything's up-to-date. Nothing to do

List item

Answer 1

Egg on my face.

The exclamation mark omission seems to be the issue.

from

@product = @list.products.create(product_params)

to this and it works

@product = @list.products.create!(product_params)