Rails 2.0 - What's a Newbie to Do?

With the recent release of Rails 2.0.0, 2.0.1, and now 2.0.2 in rapid succession, the Rails support discussion groups have had frequent inquiries from newcomers to Rails who are having problems following popular tutorials such as the books "Agile Web Development with Rails" by Dave Thomas and David Heinemeier Hansson. The Thomas/Hansson book, which is commonly referred to as AWDR is already in it's second edition which is just about a year old and covers Rails 1.2.

While the difference between Rails 2.0 and its predecessor Rails 1.2 are far less drastic than those between Rails 1.2 and Rails 1.1, enough potholes are there to trip up the unsuspecting newbie.

One of the themes of Rails 2.0 was to make it leaner. This means that some features which were previously standard have been removed from the core and relegated to plugins. For someone following a tutorial based on an 1.2, this can be a stumbling block. Two examples:

1.  Many tutorials are base on using MySql as the database adapter because it has always been the Rails 'default.' Up to now, that is, Rails 2.0.3 changed the default to Sqlite3. AWDR describes how to use Sqlite3, later in the book, but a newbie following along might not be equipped to troubleshoot the problem without help at the time it's encountered.
2. The early parts of AWDR make use of the dynamic scaffolding feature of Rails which now is only available after the scaffolding plugin has been installed with:

             script/plugin install scaffolding 

   Other such "missing" features in Rails 2.0 include AJAX in-place-editing and auto-completion, and some of the popular acts_as_x model extensions. Someone following an aging tutorial might try running the command:

             script/plugin list 

   to see if one of the available plugins looks like it might provide a missing feature.

Another option is to use Rails 1.2.6, work through the tutorial(s) and then consider moving to 2.0. First, install the 1.2.6 version of Rails:

    gem install rails --version 1.2.6 

Then, either remove any rails 2.0.x gems you have installed, or specify the version on the rails command when you generate your project:

    rails _1.2.6_ my_rails_project 

Most commands installed by gems are wrappers which invoke the code in the gem, and allow you to specify the version of the gem used by calling them with a version number surrounded by underscores as the first argument.

There are already some books which cover Rails 2.0 available such as "The Rails Way" by Obie Fernandez, but so far they all seem to be targeted as resources for those with a little more Rails experience under the belt. Some of the "Classic" Rails literature will no doubt be updated as time goes on, and newer tutorials will join them.

In the meantime the Rails newbie has the choice of either struggling through the changes as they are encountered, or perhaps more wisely using the version of Rails which matches the tutorial until a certain level of mastery has been achieved.