require 'set' require 'surrounded/exceptions' require 'surrounded/context/role_map' require 'surrounded/context/seclusion' require 'surrounded/context/role_builders' require 'surrounded/context/initializing' require 'surrounded/context/forwarding' require 'surrounded/context/trigger_controls' require 'surrounded/access_control' require 'surrounded/shortcuts' require 'surrounded/east_oriented' require 'surrounded/context/name_collision_detector' # Extend your classes with Surrounded::Context to handle their # initialization and application of behaviors to the role players # passed into the constructor. # # The purpose of this module is to help you create context objects # which encapsulate the interaction and behavior of objects inside. module Surrounded module Context def self.extended(base) base.class_eval { extend Seclusion, RoleBuilders, Initializing, Forwarding, NameCollisionDetector @triggers = Set.new include InstanceMethods trigger_mod = Module.new const_set('TriggerMethods', trigger_mod) include trigger_mod extend TriggerControls } end private # Set the default type of implementation for role methods for all contexts. def self.default_role_type @default_role_type ||= :module end class << self attr_writer :default_role_type end def default_role_type @default_role_type ||= Surrounded::Context.default_role_type end # Set the default type of implementation for role method for an individual context. def default_role_type=(type) @default_role_type = type end # Provide the ability to create access control methods for your triggers. def protect_triggers; self.extend(::Surrounded::AccessControl); end # Automatically create class methods for each trigger method. def shortcut_triggers; self.extend(::Surrounded::Shortcuts); end # Automatically return the context object from trigger methods. def east_oriented_triggers; self.extend(::Surrounded::EastOriented); end # === Utility shortcuts def role_const_defined?(name) const_defined?(name, false) end # Conditional const_get for a named role behavior def role_const(name) if role_const_defined?(name) const_get(name) end end # Allow alternative implementations for the role map # This requires that the specified mapper klass have an # initializer method called 'from_base' which accepts a # class name used to initialize the base object def role_mapper_class(mapper: RoleMap, base: ::Triad) @role_mapper_class ||= mapper.from_base(base) end module InstanceMethods # Check whether a given name is a role inside the context. # The provided block is used to evaluate whether or not the caller # is allowed to inquire about the roles. def role?(name, &block) return false unless role_map.role?(name) accessor = block.binding.eval('self') role_map.role_player?(accessor) && role_map.assigned_player(name) end # Check if a given object is a role player in the context. def role_player?(obj) role_map.role_player?(obj) end # Return a Set of all defined triggers def triggers self.class.triggers end # Reuse the same context object but pass new values def rebind(**options_hash) clear_instance_variables begin initialize(**options_hash) rescue ArgumentError initialize(*options_hash.values) end self end private def clear_instance_variables instance_variables.each{|ivar| remove_instance_variable(ivar) } end def role_map @role_map ||= role_mapper_class.new end def map_roles(role_object_array) detect_collisions role_object_array role_object_array.to_a.each do |role, object| if self.respond_to?("map_role_#{role}") self.send("map_role_#{role}", object) else map_role(role, role_behavior_name(role), object) map_role_collection(role, role_behavior_name(role), object) end end end def map_role_collection(role, mod_name, collection) singular_role_name = singularize_name(role) singular_behavior_name = singularize_name(role_behavior_name(role)) if collection.respond_to?(:each_with_index) && role_const_defined?(singular_behavior_name) collection.each_with_index do |item, index| map_role(:"#{singular_role_name}_#{index + 1}", singular_behavior_name, item) end end end def map_role(role, mod_name, object) instance_variable_set("@#{role}", object) role_map.update(role, role_module_basename(mod_name), object) end def apply_behavior(role, behavior, object) if behavior && role_const_defined?(behavior) applicator = if self.respond_to?("apply_behavior_#{role}") method("apply_behavior_#{role}") elsif role_const(behavior).is_a?(Class) method(:apply_class_behavior) else method(:apply_module_behavior) end role_player = applicator.call(role_const(behavior), object) map_role(role, behavior, role_player) end role_player || object end def apply_module_behavior(mod, obj) adder_name = module_extension_methods.find{|meth| obj.respond_to?(meth) } return obj unless adder_name obj.method(adder_name).call(mod) obj end def apply_class_behavior(klass, obj) wrapper_name = wrap_methods.find{|meth| klass.respond_to?(meth) } return obj if !wrapper_name klass.method(wrapper_name).call(obj) end def remove_behavior(role, behavior, object) if behavior && role_const_defined?(behavior) remover_name = (module_removal_methods + unwrap_methods).find do |meth| object.respond_to?(meth) end end role_player = if self.respond_to?("remove_behavior_#{role}") self.send("remove_behavior_#{role}", role_const(behavior), object) elsif remover_name object.send(remover_name) end role_player || object end def apply_behaviors role_map.each do |role, mod_name, object| player = apply_behavior(role, mod_name, object) if player.respond_to?(:store_context, true) player.__send__(:store_context) do; end end end end def remove_behaviors role_map.each do |role, mod_name, player| if player.respond_to?(:remove_context, true) player.__send__(:remove_context) do; end end remove_behavior(role, mod_name, player) end end # List of possible methods to use to add behavior to an object from a module. def module_extension_methods [:cast_as, :extend] end # List of possible methods to use to add behavior to an object from a wrapper. def wrap_methods [:new] end # List of possible methods to use to remove behavior from an object with a module. def module_removal_methods [:uncast] end # List of possible methods to use to remove behavior from an object with a wrapper. def unwrap_methods [:__getobj__] end def role_behavior_name(role) RoleName.new(role) end def role_module_basename(mod) mod.to_s.split('::').last end def role_const(name) self.class.send(:role_const, name) end def role_const_defined?(name) self.class.send(:role_const_defined?, name) end def role_mapper_class self.class.send(:role_mapper_class) end def singularize_name(name) if name.respond_to?(:singularize) name.singularize else # good enough for now but should be updated with better rules name.to_s.tap do |string| if string =~ /ies\z/ string.sub!(/ies\z/,'y') elsif string =~ /s\z/ string.sub!(/s\z/,'') end end end end end class RoleName def initialize(string, suffix=nil) @string = string. to_s. split(/_/). map{|part| part.capitalize }. join. sub(/_\d+/,'') + suffix.to_s end def to_str @string end alias to_s to_str def to_sym @string.to_sym end end end end