I started this series nearly two weeks ago with a pretty solid understanding of both Devise and SimpleDB (via AWS::Record::Model in aws-sdk) as individual pieces. In the course of getting them to work together I’ve learned a lot about the internals of both projects (also ActiveModel and ActiveRecord), created three new gems, and had a few pull requests accepted into the aws-sdk gem. In this post I’m going to do some more refactoring of the ongoing SimpleDevise project to correct an early mis-step and to remove some methods that are now provided by aws-sdk.

Update the Gemfile

First, we need to update the aws-sdk gem to point to the current project on Github. Once version 1.8.1 has been released here, we’ll be able to go back to a regular gem release. So, find the line for aws-sdk in the Gemfile and change it to look like this:

gem "aws-sdk", :git => "git://github.com/aws/aws-sdk-ruby.git"

This will pick up 3 updates that provide functionality that we need.

• One to add #create and #create! methods to AWS::Record::Model
• One to add an :allow_blank option to some validations
• And one to add a :validate option to the #save method of AWS::Record::Model

We also need to add a new gem

gem "simple_date_fix", "~> 0.0.4"

SimpleDateFix is based on work done by daniel-nelson to get queries and sorting to work correctly on datetime_attrs in AWS::Record::Model. Thanks, Daniel!

Now, we just need to install the updates, so run:

$ bundle install

Now we can start the refactoring.

Correcting a mis-step

One of the steps taken in part 1 was just the wrong course of action. After coming to understand the problem more thoroughly I ended up making pull requests to the aws-sdk gem to correct the problem.

First, open config/initializers/aws.rb and remove these lines:

AWS::Record::FormatValidator::ACCEPTED_OPTIONS << :allow_blank
AWS::Record::LengthValidator::ACCEPTED_OPTIONS << :allow_blank

It turns out that just faking out these validators doesn’t really cut it. This pull request added proper handling for the :allow_blank option, so now Devise will be happy AND things will work like it expects them to.

Remove unnecessary duplicate code

Since we’re using a new version of aws-sdk that contains some new methods we can get rid of our own custom version of those methods.

Open up the User model in app/models/user.rb and remove the following lines:

# Some methods to fake out Devise
  def save opts = {}
    if valid?(opts)
      persisted? ? update : create
      clear_changes!
      true
    else
      false
    end
  end

  def valid? opts = {}
    opts = {} if opts.nil?
    opts = {:validate => true}.merge(opts)
    run_validations if opts[:validate]
    errors.empty?
  end

Both of those methods were there to allow Devise to skip validations during a #save operation, and the ability to skip validations was added to aws-sdk by this pull request.

That’s it! This was just a small bit of refactoring to get things onto the right track. We got rid of a dirty hack that wasn’t doing us any real good and we got to remove some code that is now a part of the aws-sdk library. It’s always nice to be able to trim your codebase by delegating functionality where it belongs. In the next part I plan to add some some testing to the app.

You can find the source code for this project on Github.