Enumerate all Rails ActiveRecord::Base model classes

I couldn't quickly find an easy way to enumerate all ActiveRecord::Base-derived model classes in my Rails project (for some simple analysis scripts), so I whipped up this quick and dirty solution.

	# Add AR::Base class methods for enumerating all the model
	# classes in a Rails project.
	module ActiveRecord
	class Base
	def self.all_model_classes
	connection.tables.map do |table|
	begin
	klass = Class.const_get(table.classify)
	klass.ancestors.include?(self) ? klass : nil
	rescue
	nil
	end
	end.compact
	end
	def self.each_model_class(&block)
	all_model_classes.each(&block)
	end
	end
	end

view raw enum_models.rb hosted with ❤ by GitHub

I extended ActiveRecord::Base just out of convenience, so I can call ActiveRecord::Base.each_model_class{|klass| ...} easily. You could apply the same technique in another class if you don't like extending Rails core classes.

The "rescue nil" is just a quick hack to catch the cases where you have tables that don't map to classes directly.

NOTE: This does NOT enumerate STI-based model classes that don't have their own tables.