Keeping uploaded files between deployments

You are using file_column plugin (or maybe another plugin?), to upload files in your ruby on rails application. Because the files are big you don’t want to have a different copy stored in your subversion repository for each different deployment version. You want to keep a common folder with all your uploaded files, and use it with every different deployment version.

For the example, we will have a numbers table that has two file_column uploadable columns (intro,voice_mail), with the following migration:

class CreateNumbers < ActiveRecord::Migration
  def self.up
    create_table :numbers do |t|
      t.column :customer_id, :int, :null => false
      t.column :phone_no, :string, :null => false
      t.column :intro, :string
      t.column :vmail, :string
      t.column :created_at, :datetime
      t.column :updated_at, :datetime

  def self.down
    drop_table :numbers
  1. If you already have used cap deploy or cap setup you should have a shared folder in your deployment server.
    You should copy the intro and vmail folders that should be located on your public/number folder on your local development client, on a folder called number in your development server in your shared folder.
  2. Create a file in your local pc in lib/cap_recipes.rb:
    Capistrano.configuration(:must_exist).load do
      desc "Keep generated uploaded files between deployments"
        task :after_symlink do
           run "rm -drf #{deploy_to}/#{current_dir}/public/number"
           sudo "ln -nfs #{shared_path}/number #{deploy_to}/#{current_dir}/public"

    Be careful with the naming of the task as (at least for capistrano 1.4 that I’m using), it must have a special name as after_symlink.
    Also be careful that if you try to use before_symlink, it won’t work as the current symlink won’t be setup.

  3. In your config/deploy.rb file add at the top the following:
    require 'lib/cap_recipes'
  4. Now you should be ready to deploy your new version so:
    svn -m "added customised capistrano recipes" commit

    make sure that you check in your version in subversion, and then:

    cap deploy

    you should be able to see a link in your current/public folder called number that points to the shared/number folder that hold all the uploaded files.

Adding icons to ActiveScaffold’s actions

You want to replace the standard text descriptions in ActiveScaffold’s actions with your icons.


  1. Create a file called active_scaffold_overrides.css in ror_project/public/stylesheets
  2. Copy the css code from ror_project/vendor/plugins/active_scaffold/frontends/default/stylesheets/stylesheet.css and paste it in to the file created in the previous step.
  3. Create a directory my_images in ror_project/public/images/activescaffold to hold your images.
  4. Copy to the new directory the images you want to use in the application.
  5. In the active_scaffold_overrides.css file find the section named:
    /* Table :: Actions (Edit,Delete) .... */

    and for each action that you want to use an icon add (ie edit)

    .active_scaffold tr.record td.actions a.edit {
        display:     block;
        width:        16px;
        height:       16px;
        background: transparent url(../../../images/active_scaffold/my_images/image.png) no-repeat right 50%;
  6. In the application.rb, if you want the links to be the same for the whole application add:
    ActiveScaffold.set_defaults do |config| =""
  7. in your layout/application.rhtml (create one if you don’t already have one), include
    <%= stylesheet_link_tag "active_scaffold_overrides" %>
  8. Restart webrick/mongrel

Controller testing in Active Scaffold


You need to have to functionally test your controller when you are using ActiveScaffold. There are pieces of code that tell you how to do that on a normal ror application (ie without ActiveScaffold), like recipe 7.17 on the Rails Cookbook, or a fragment of code in an Active Scaffold application, but they don’t have the full details.


Here is an attempt to give some more detailed step by step instructions on how to do it.

  1. The migration for the example customer model.
  2. class CreateCustomers < ActiveRecord::Migration
      def self.up
        # Create customers table
        create_table  :customers do |t|
          t.column  :customer_code, :string, :null => false
          t.column  :created_at, :datetime
          t.column  :updated_at, :datetime
  3. The customer model, with the extra function to display the customer code
  4. class Customer < ActiveRecord::Base
      has_many    :numbers
      def to_label
  5. The customer controller app/controllers/customers_controller.rb, using the Active Scaffold
  6. class CustomersController < ApplicationController
      active_scaffold :customer do |config|
        config.list.columns = [:customer_code, :numbers, :created_at, :updated_at]
        config.columns[:customer_code].inplace_edit = true
  7. The fixtures YML file test/fixtures/customers.yml
  8. first_customer:
      id:               1
      customer_code:    123
      created_at:       2007-09-26 11:17:07
      updated_at:       2007-09-26 11:17:07
      id:               2
      customer_code:    456
      created_at:       2007-09-26 11:17:13
      updated_at:       2007-09-26 11:17:13
  9. And here are some functions to test some pages and a full CRUD test
  10. require File.dirname(__FILE__) + '/../test_helper'
    require 'customers_controller'
    class CustomerControllerTest < Test::Unit::TestCase
      fixtures  :customers
      def setup
        @controller =
        @request =
        @response =
      def test_index
        get :index
        assert_response :success
        assert_template 'list'
      def test_new
        get :new
        assert_response :success
        assert_template 'create_form'
      def test_edit
        get :edit, :id => customers(:first_customer).id
        assert_response :success
        assert_template 'update_form'
      def test_show
        get :show, :id => customers(:first_customer).id
        assert_response :success
        assert_template 'show'
      def test_customer_controller_CRUD
        # CREATE
        # Get the number of records
        record_no = Customer.count
        # Create a new record
        post  :create, {"commit"=>"Create", :record=>{"customer_code"=>"890"}}
        # Assert that the record is not nil
        assert_not_nil  assigns("record")
        # Look that the number of records has been increased by 1
        assert_equal  record_no+1, Customer.count
        # UPDATE
        # Get the number of records
        record_no = Customer.count
        # Update a record
        new_customer_code = "987"
        put :update, {"commit"=>"Update",:id=>customers(:first_customer).id,
        # Assert that the record is not nil
        assert_not_nil  assigns("record")
        # Look that the number of records has stayed the same
        assert_equal  record_no, Customer.count
        # Check that the update took place
        customer = Customer.find(customers(:first_customer).id)
        assert_equal  new_customer_code, customer.customer_code
        # DELETE
        # Get the number of records
        record_no = Customer.count
        # Delete a record
        delete  :destroy, :id => customers(:first_customer).id
        # Look that the number of records has been decreased by 1
        assert_equal  record_no-1, Customer.count

:int and :integer problem in Ruby on Rails migration

After spending some time trying to make a migration work, and having the error message coming back:

You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.[]

I’ve decided to do a google search for the specific problem, as it was working fine with other test migrations.

It turns out that if the migration is not model specific, but a different one (ie trying to add a new column to an existing table), the :int for the column doesn’t work!
It has to be :integer.
Full bug report and the article are here:
Migrations: :integer works, :int doesn’t – datatype discrepancy

dhtmlcalendar in ActiveScaffold

To control the date format in dhtmlcalendar within ActiveScaffold in Ruby on Rails, to make the date of 2 November 2007 appear like 02-11-2007, use:

i) if you want to affect the settings in all the application add the following to the top of your controllers/application.rb

ActiveSupport::CoreExtensions::Date::Conversions::DATE_FORMAT[:default] = ‘%d-%m-%Y’

ii) If you only want to affect the settings of the calendar in one specific controller, then add the same line only to the controller that you want:

ActiveSupport::CoreExtensions::Date::Conversions::DATE_FORMAT[:default] = '%d-%m-%Y'