Rails%203%20In%20Action

224 CHAPTER 9 File uploading
9.2.2 Using nested attributes
You used the term Asset rather than File throughout this application because of this
model. You can’t define a File model because there’s already a File class in Ruby.
Asset is an alternative name you can use. To define this Asset constant in your application,
you can run the model generator:
rails g model asset
Each record for this model refers to a single file that has been uploaded to a ticket.
Therefore, each record in the assets table must have the same asset_* fields that
each tickets record currently has. Storing the asset references in the assets table
now makes the references in the tickets table irrelevant, so you should remove them.
You should also add a relationship between the asset records and the ticket records by
adding a ticket_id field to the assets table. Open the migration this generates, and
change it to the following listing to reflect these ideas.
Listing 9.7 db/migrate/[date]_create_assets.rb
class CreateAssets < ActiveRecord::Migration
def change
create_table :assets do |t|
t.string :asset_file_name
t.integer :asset_file_size
t.string :asset_content_type
t.datetime :asset_updated_at
t.integer :ticket_id
t.timestamps
end
[:asset_file_name,
:asset_file_size,
:asset_content_type,
:asset_updated_at].each do |column|
remove_column :tickets, column
end
end
end
Run this migration with rake db:migrate to migrate your development environment’s
database, and then run rake db:test:prepare to migrate the test environment’s database.
When you run the feature again with bin/cucumber features/creating
_tickets.feature:36, your File #1 field is once again missing:
And I attach the file "spec/fixtures/speed.txt" to "File #1"
cannot attach file, no file field with id, name,
or label 'File #1' found (Capybara::ElementNotFound)
You’ve gone backward! Or so it seems.
As mentioned earlier, fields_for detects that the assets method is defined on
your Ticket object and then iterates through each object in this collection while rendering
the fields inside fields_for for each. When you create a new ticket in