Note that this card is very old. You might want to use ActiveType for your auto-coerced virtual attributes instead...
Don't insert table rows in a Rails database migration. This will break tests that expect that database to be...
Plugins (and gems) are typically tested using a complete sample rails application that lives in the spec folder of the...
There is a problem with AJAX response handling for Rails 3 remote links and forms in Internet Explorer. This problem...
Thanks to habits engrained by Rails 2’s link_to_remote and remote_form_for, we expect that Rails 3...
Terminus is a Capybara driver where most of the driver functions are implemented in client-side JavaScript. It lets you...
Sometimes you inherit a non Rails or non Rack based web app such as PHP, Perl, Java / JEE, etc. I...
You can now add an :inverse_of option to has_one, has_many and belongs_to associations.... Without :inverse_of...
After switching to Rails 3 you may get a LoadError with the following message when trying to use your application...
You might find that your Passenger ignores all RailsSomething directives in the vhost for your new Rails 3 application. The...
You will need to upgrade to RSpec >= 2 and rspec-rails >= 2 for Rails 3. Here are some hints to...
Be careful when using params.merge as params is a HashWithIndifferentAccess. Why? Usually this should not be an issue but it...
In rare cases you might need something like form_for (for using form builder methods on the resulting block element...
When using form_for you can give the form's target URL either as a string or an array:
The ancestry gem allows you to easily use tree structures in your Rails application. There is one somewhat unobvious pitfall...
If you need to look at the list of methods that are called upon certain events (like before/after saving etc...
SSL in Rails 3 is non-obvious.
If you want to see how long your database queries actually take, you need to disable MySQL's query cache...
If you get an error message like that you are missing the Aspell files a specific language:
Even when you're using bundler, it might be significant in which order your gems are listed in your Gemfile...
You can use record.send(:update_without_callbacks) or record.send(:create_without_callbacks) This can be used as a...
You don't need a Rails application to use Sass. Even when you're working on a static site you...
For some reason you want to define a find condition in array form. And in that condition both column name...
Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft...