module SimpleModel
module Attributes
include ExtendCore
extend ActiveSupport::Concern
include ActiveModel::AttributeMethods
def initialize(*attrs)
attrs = attrs.extract_options!
attrs = attributes_with_for_init(attrs)
attrs = self.class.before_initialize.call(self,attrs) if self.class.before_initialize
set(attrs)
self.class.after_initialize.call(self) if self.class.after_initialize
end
# Returns true if attribute has been initialized
def initialized?(attr)
attributes.key?(attr.to_sym)
end
def attributes
@attributes ||= HashWithIndifferentAccess.new
end
def attributes=attrs
@attributes = attrs
end
def get(attr)
self.send(attr)
end
alias :read :get
# Accepts a hash where the keys are methods and the values are values to be set.
# set(:foo => "bar", :dime => 0.1)
def set(*attrs)
attrs.extract_options!.each do |attr,val|
self.send("#{attr.to_s}=",val)
end
end
alias :set_attributes :set
private
def fetch_default_value(arg)
return self.send(arg) if (arg.is_a?(Symbol) && self.respond_to?(arg))
arg
end
# Returns attribute that have defaults in a hash: {:attribute => "default value"}
# Checks for alias attributes to ensure they are not overwritten
def attributes_with_for_init(attrs)
d = attrs.with_indifferent_access
self.class.defined_attributes.each do |k,v|
if allow_set_default?(d,k,v)
d[k] = fetch_default_value(v[:default])
end
end
d
end
def allow_set_default?(d,k,v)
(v[:default] && v[:initialize] && (d[k].blank? && (self.class.alias_attributes[k].blank? || d.key?(self.class.alias_attributes[k]) && d[self.class.alias_attributes[k]].blank?)))
end
private
def allow_attribute_action?(obj,val,options)
return true if (options[:if].blank? && options[:unless].blank?)
b = true
if options[:if].is_a?(Symbol)
if options[:if] == :blank
b = (b && val.blank?)
else
b = (b && send(options[:if]))
end
end
b = (b && options[:if].call(obj,val)) if options[:if].is_a?(Proc)
if options[:unless].is_a?(Symbol)
if options[:unless] == :blank
b = (b && !val.blank?)
else
b = (b && !send(options[:unless]))
end
end
b = (b && !options[:unless].call(obj,val)) if options[:unless].is_a?(Proc)
b
end
# Rails 3.2 + required when searching for attributes in from inherited classes/models
def attribute(name)
attributes[name.to_sym]
end
module ClassMethods
# Creates a new instance where the attributes store is set to object
# provided, which allows one to pass a session store hash or any other
# hash-like object to be used for persistence. Typically used for modeling
# session stores for authorization or shopping carts
# EX:
# class ApplicationController < ActionController::Base
# def session_user
# session[:user] ||= {}
# @session_user ||= SessionUser.new_with_store(session[:user])
# end
# helper_method :session_user
# end
#
def new_with_store(session_hash)
new = self.new()
new.attributes = session_hash
new.set(new.send(:attributes_with_for_init,session_hash))
new
end
def alias_attributes
@alias_attributes ||= HashWithIndifferentAccess.new
end
def alias_attributes=alias_attributes
@alias_attributes = alias_attributes
end
def defined_attributes
@defined_attributes ||= HashWithIndifferentAccess.new
end
def defined_attributes=defined_attributes
@defined_attributes = defined_attributes
end
def attribute_defined?(attr)
(self.defined_attributes.member?(attr) || self.superclass.respond_to?(:attribute_defined?) && self.superclass.attribute_defined?(attr))
end
# The default settings for a SimpeModel class
# Options:
# * :on_set - accepts a lambda that is run when an attribute is set
# * :on_get - accepts a lambda that is run when you get/read an attribute
# * :default - the default value for the attribute, can be a symbol that is sent for a method
# * :initialize - informations the object whether or not it should initialize the attribute with :default value, defaults to true
# ** If :initialize is set to false you must set :allow_blank to false or it will never set the default value
# * :allow_blank - when set to false, if an attributes value is blank attempts to set the default value, defaults to true
def default_attribute_settings
@default_attribute_settings ||= {:attributes_method => :attributes,
:on_set => lambda {|obj,attr| attr},
:on_get => lambda {|obj,attr| attr},
:allow_blank => true,
:initialize => true
}
end
def default_attribute_settings=default_attribute_settings
@default_attribute_settings = default_attribute_settings
end
# We want to re-run define_attribute_methods since attributes are not all defined
# at once, so we must set @attribute_methods_generated to nil to allow the
# re-run to occur ONLY IN RAILS 3.0.
def add_defined_attribute(attr,options)
self.defined_attributes[attr] = options
@attribute_methods_generated = nil #if (ActiveModel::VERSION::MAJOR == 3 && ActiveModel::VERSION::MINOR == 0)
define_attribute_methods(self.defined_attributes.keys)
end
# builds the setter and getter methods
def create_attribute_methods(attributes,options)
unless attributes.blank?
attributes.each do |attr|
define_reader_with_options(attr,options)
define_setter_with_options(attr,options)
end
end
end
def define_reader_with_options(attr,options)
add_defined_attribute(attr,options)
options = default_attribute_settings.merge(options) if options[:on_get].blank?
define_method(attr) do
val = self.attributes[attr]
if (options.key?(:default) && (!self.initialized?(attr) || (!options[:allow_blank] && val.blank?)))
val = self.attributes[attr] = fetch_default_value(options[:default])
end
options[:on_get].call(self,val)
end
define_method("#{attr.to_s}?") do
return false unless initialized?(attr)
val = self.send(attr)
if val.respond_to?(:to_b)
val = val.to_b
else
val = !val.blank? if val.respond_to?(:blank?)
end
val
end
end
# Creates setter methods for the provided attributes
# On set, it will mark the attribute as changed if the attributes has been
# initialized.
def define_setter_with_options(attr,options)
add_defined_attribute(attr,options)
options = default_attribute_settings.merge(options) if (options[:on_set].blank? || options[:after_set].blank?)
define_method("#{attr.to_s}=") do |val|
if allow_attribute_action?(self,val,options)
val = fetch_default_value(options[:default]) if (!options[:allow_blank] && options.key?(:default) && val.blank?)
val = options[:on_set].call(self,val) unless (val.blank? && !options[:allow_blank] )
will_change = "#{attr}_will_change!".to_sym
self.send(will_change) if (initialized?(attr) && val != self.attributes[attr])
self.attributes[attr] = val
options[:after_set].call(self,val) if options[:after_set]
end
end
end
AVAILABLE_ATTRIBUTE_METHODS = {
:has_attribute => {:alias => :has_attributes},
:has_boolean => {:cast_to => :to_b, :alias => :has_booleans},
:has_currency => {:cast_to => :to_d, :alias => :has_currencies},
:has_date => {:cast_to => :to_date, :alias => :has_dates} ,
:has_decimal => {:cast_to => :to_d, :alias => :has_decimals},
:has_float => {:cast_to => :to_f, :alias => :has_floats},
:has_int => {:cast_to => :to_i, :alias => :has_ints},
:has_time => {:cast_to => :to_time, :alias => :has_times}
}
AVAILABLE_ATTRIBUTE_METHODS.each do |method,method_options|
define_method(method) do |*attributes|
options = default_attribute_settings.merge(attributes.extract_options!)
options[:on_set] = lambda {|obj,val| val.send(method_options[:cast_to]) } if method_options[:cast_to]
create_attribute_methods(attributes,options)
end
module_eval("alias #{method_options[:alias]} #{method}")
end
# Creates alias setter and getter for the supplied attribute using the supplied alias
# See spec for example.
def alias_attribute(new_alias,attribute)
alias_attributes[attribute] = new_alias
define_method(new_alias) do
self.send(attribute)
end
define_method("#{new_alias.to_s}=") do |*args, &block|
self.send("#{attribute.to_s}=",*args, &block)
end
end
# A hook to perform actions on the pending attributes or the object before
# the pending attributes have been initialized.
# Expects an lambda that accept the object, the pending attributes hash and
# should return a hash to be set
# EX: lambda {|obj,attrs| attrs.select{|k,v| !v.blank?}}
def before_initialize
@before_initialize
end
# Expects an lambda that accept the object, the pending attributes hash and
# should return a hash to be set
# EX: lambda {|obj,attrs| attrs.select{|k,v| !v.blank?}}
def before_initialize=before_initialize
raise TypeError "before_initialize must be a lambda that accepts the attirbutes to be initialize" unless before_initialize.is_a?(Proc)
@before_initialize = before_initialize
end
# A hook to perform actions after all attributes have been initialized
# Expects an lambda that accept the object and the pending attributes hash
# EX: lambda {|obj| puts "initialized"}
def after_initialize
@after_initialize
end
# Expects an lambda that accept the object and the pending attributes hash
# EX: lambda {|obj| puts "initialized"}
def after_initialize=after_initialize
raise TypeError "after_initalize must be a Proc" unless after_initialize.is_a?(Proc)
@after_initialize = after_initialize
end
# Must inherit super's defined_attributes and alias_attributes
# Rails 3.0 does some weird stuff with ActiveModel::Dirty so we need a
# hack to keep things working when a class inherits from a super that
# has ActiveModel::Dirty included
def inherited(base)
base.alias_attributes = self.alias_attributes.merge(base.alias_attributes)
super
# Rails 3.0 Hack
if (ActiveModel::VERSION::MAJOR == 3 && ActiveModel::VERSION::MINOR == 0)
base.attribute_method_suffix '_changed?', '_change', '_will_change!', '_was'
base.attribute_method_affix :prefix => 'reset_', :suffix => '!'
end
end
end
# Rails 3.0 does some weird stuff with ActiveModel::Dirty so we need a
# hack to keep things working when a class includes a module that has
# ActiveModel::Dirty included
def self.included(base)
base.extend(Attributes::ClassMethods)
base.send(:include, ActiveModel::Dirty)
base.send(:include, ActiveModel::Validations)
base.send(:include, ActiveModel::Conversion)
base.extend ActiveModel::Naming
base.extend ActiveModel::Callbacks
base.send(:include, ActiveModel::Validations::Callbacks)
# Rails 3.0 Hack
if (ActiveModel::VERSION::MAJOR == 3 && ActiveModel::VERSION::MINOR == 0)
base.attribute_method_suffix '_changed?', '_change', '_will_change!', '_was'
base.attribute_method_affix :prefix => 'reset_', :suffix => '!'
end
end
end
end