require File.dirname(__FILE__) + '/module_attribute_accessors' module Dependencies extend self @@loaded = [ ] mattr_accessor :loaded @@mechanism = :load mattr_accessor :mechanism def load? mechanism == :load end def depend_on(file_name, swallow_load_errors = false) if !loaded.include?(file_name) loaded << file_name begin require_or_load(file_name) rescue LoadError raise unless swallow_load_errors end end end def associate_with(file_name) depend_on(file_name, true) end def clear self.loaded = [ ] end def require_or_load(file_name) file_name = "#{file_name}.rb" unless ! load? || /\.rb$/ =~ file_name load? ? load(file_name) : require(file_name) end def remove_subclasses_for(*classes) classes.each { |klass| klass.remove_subclasses } end # LoadingModules implement namespace-safe dynamic loading. # They support automatic loading via const_missing, allowing contained items to be automatically # loaded when required. No extra syntax is required, as expressions such as Controller::Admin::UserController # load the relavent files automatically. # # Ruby-style modules are supported, as a folder named 'submodule' will load 'submodule.rb' when available. class LoadingModule < Module attr_reader :path attr_reader :root def self.root(*load_paths) RootLoadingModule.new(*load_paths) end def initialize(root, path=[]) @path = path.clone.freeze @root = root end def root?() self.root == self end def load_paths() self.root.load_paths end # Load missing constants if possible. def const_missing(name) const_load!(name) ? const_get(name) : super(name) end # Load the controller class or a parent module. def const_load!(name, file_name = nil) path = self.path + [file_name || name] load_paths.each do |load_path| fs_path = load_path.filesystem_path(path) next unless fs_path if File.directory?(fs_path) new_module = LoadingModule.new(self.root, self.path + [name]) self.const_set name, new_module if self.root? if Object.const_defined?(name) msg = "Cannot load module #{name}: Object::#{name} is set to #{Object.const_get(name).inspect}" raise NameError, msg end Object.const_set(name, new_module) end break elsif File.file?(fs_path) self.root.load_file!(fs_path) # Import the loaded constant from Object provided we are the root node. self.const_set(name, Object.const_get(name)) if self.root? && Object.const_defined?(name) break end end return self.const_defined?(name) end # Is this name present or loadable? # This method is used by Routes to find valid controllers. def const_available?(name) self.const_defined?(name) || load_paths.any? {|lp| lp.filesystem_path(path + [name])} end end class RootLoadingModule < LoadingModule attr_reader :load_paths def initialize(*paths) @load_paths = paths.flatten.collect {|p| p.kind_of?(ConstantLoadPath) ? p : ConstantLoadPath.new(p)} end def root() self end def path() [] end # Load the source file at the given file path def load_file!(file_path) require_dependency(file_path) end # Erase all items in this module def clear! constants.each do |name| Object.send(:remove_const, name) if Object.const_defined?(name) && Object.const_get(name).object_id == self.const_get(name).object_id self.send(:remove_const, name) end end end # This object defines a path from which Constants can be loaded. class ConstantLoadPath # Create a new load path with the filesystem path def initialize(root) @root = root end # Return nil if the path does not exist, or the path to a directory # if the path leads to a module, or the path to a file if it leads to an object. def filesystem_path(path, allow_module=true) fs_path = [@root] fs_path += path[0..-2].collect {|name| const_name_to_module_name name} if allow_module result = File.join(fs_path, const_name_to_module_name(path.last)) return result if File.directory? result # Return the module path if one exists end result = File.join(fs_path, const_name_to_file_name(path.last)) return File.file?(result) ? result : nil end def const_name_to_file_name(name) name.to_s.underscore + '.rb' end def const_name_to_module_name(name) name.to_s.underscore end end end Object.send(:define_method, :require_or_load) { |file_name| Dependencies.require_or_load(file_name) } unless Object.respond_to?(:require_or_load) Object.send(:define_method, :require_dependency) { |file_name| Dependencies.depend_on(file_name) } unless Object.respond_to?(:require_dependency) Object.send(:define_method, :require_association) { |file_name| Dependencies.associate_with(file_name) } unless Object.respond_to?(:require_association) class Object #:nodoc: class << self # Use const_missing to autoload associations so we don't have to # require_association when using single-table inheritance. def const_missing(class_id) if Object.const_defined?(:Controllers) and Object::Controllers.const_available?(class_id) return Object::Controllers.const_get(class_id) end begin require_dependency(class_id.to_s.demodulize.underscore) if Object.const_defined?(class_id) then return Object.const_get(class_id) else raise LoadError end rescue LoadError => e raise NameError.new("uninitialized constant #{class_id}").copy_blame!(e) end end end def load(file, *extras) begin super(file, *extras) rescue Object => exception exception.blame_file! file raise end end def require(file, *extras) begin super(file, *extras) rescue Object => exception exception.blame_file! file raise end end end # Add file-blaming to exceptions class Exception def blame_file!(file) (@blamed_files ||= []).unshift file end def blamed_files @blamed_files ||= [] end def describe_blame return nil if blamed_files.empty? "This error occured while loading the following files:\n #{blamed_files.join "\n "}" end def copy_blame!(exc) @blamed_files = exc.blamed_files.clone self end end