Rails conventionsEdit

Rails argues for "convention over configuration" to minimize time spent by programmers worrying about menial details and maximize time spent on substantive problem solving.

Model and controller naming conventions

• Model and class names are singular (Weblog, Post) and in CamelCase (AccessControlList); if you use script/generate model to create a model the class file will be in lowercase, singular, separated by underscores (weblog.rb, post.rb, access_control_list.rb).
• Database tables corresponding to models/classes are plural (weblogs, posts) and in lowercase, separated by underscores (access_control_lists).
• Controller names are not required to match up with underlying model names, but when they do the convention (not enforced) is to use the plural form of the model name (WeblogsController, the corresponding file name would be weblogs_controller.rb); if you use script/generate controller to create a controller file Rails will not perform and singular-to-plural conversion but will format the name in lowercase with underscore separators.
• If you use script/generate scaffold to create a scaffold Rails will create a singular model file and a plural controller file.

Database naming conventions

• Table columns of type datetime and named created_at/created_on or updated_at/updated_on will be automatically updated by Rails on record creation and record update respectively.
• Table columns named lock_version (type: integer, default: 0, null: false) will be used automatically by Rails to perform "optimistic locking" (an exception will be raised whenever a race occurs).
• A column named counter_cache can be used to save database lookups (see: http://blog.gorgorg.org/articles/2006/04/04/ruby-on-rails-how-to-actually-use_count-counter_cache).

Model inheritance conventions

Given a class hierarchy that looks like this:

• ActiveRecord::Base
  • Furniture
    1. Chair
    2. Table

Rails will expect a single table named furniture with a column named type that will be used to distinguish which rows are used for the Chair model and which for the Table model. For more information see:

• http://activerecord.rubyonrails.org/show/SingleTableInheritance
• http://rubyonrails.org/api/classes/ActiveRecord/Base.html
• http://www.martinfowler.com/eaaCatalog/singleTableInheritance.html

View conventions

• If you create a file at app/views/layouts/application.rhtml it will automatically be used as a wrapper around all other layouts.