couchrest_model/lib/couchrest/model/properties.rb

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# encoding: utf-8
module CouchRest
module Model
module Properties
extend ActiveSupport::Concern
included do
extlib_inheritable_accessor(:properties) unless self.respond_to?(:properties)
self.properties ||= []
raise "You can only mixin Properties in a class responding to [] and []=, if you tried to mixin CastedModel, make sure your class inherits from Hash or responds to the proper methods" unless (method_defined?(:[]) && method_defined?(:[]=))
end
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# Returns the Class properties
#
# ==== Returns
# Array:: the list of properties for model's class
def properties
self.class.properties
end
# Returns the Class properties with their values
#
# ==== Returns
# Array:: the list of properties with their values
def properties_with_values
props = {}
properties.each { |property| props[property.name] = read_attribute(property.name) }
props
end
# Read the casted value of an attribute defined with a property.
#
# ==== Returns
# Object:: the casted attibutes value.
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def read_attribute(property)
self[find_property!(property).to_s]
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end
# Store a casted value in the current instance of an attribute defined
# with a property.
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def write_attribute(property, value)
prop = find_property!(property)
self[prop.to_s] = prop.is_a?(String) ? value : prop.cast(self, value)
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end
# Takes a hash as argument, and applies the values by using writer methods
# for each key. It doesn't save the document at the end. Raises a NoMethodError if the corresponding methods are
# missing. In case of error, no attributes are changed.
def update_attributes_without_saving(hash)
# Remove any protected and update all the rest. Any attributes
# which do not have a property will simply be ignored.
attrs = remove_protected_attributes(hash)
directly_set_attributes(attrs)
end
alias :attributes= :update_attributes_without_saving
private
# The following methods should be accessable by the Model::Base Class, but not by anything else!
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def apply_all_property_defaults
return if self.respond_to?(:new?) && (new? == false)
# TODO: cache the default object
self.class.properties.each do |property|
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write_attribute(property, property.default_value)
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end
end
def prepare_all_attributes(doc = {}, options = {})
apply_all_property_defaults
if options[:directly_set_attributes]
directly_set_read_only_attributes(doc)
else
doc = remove_protected_attributes(doc)
end
directly_set_attributes(doc) unless doc.nil?
end
def find_property!(property)
prop = property.is_a?(Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
raise ArgumentError, "Missing property definition for #{property.to_s}" if prop.nil?
prop
end
# Set all the attributes and return a hash with the attributes
# that have not been accepted.
def directly_set_attributes(hash)
hash.reject do |attribute_name, attribute_value|
if self.respond_to?("#{attribute_name}=")
self.send("#{attribute_name}=", attribute_value)
true
elsif mass_assign_any_attribute # config option
self[attribute_name] = attribute_value
true
else
false
end
end
end
def directly_set_read_only_attributes(hash)
property_list = self.properties.map{|p| p.name}
hash.each do |attribute_name, attribute_value|
next if self.respond_to?("#{attribute_name}=")
if property_list.include?(attribute_name)
write_attribute(attribute_name, hash.delete(attribute_name))
end
end
end
def set_attributes(hash)
attrs = remove_protected_attributes(hash)
directly_set_attributes(attrs)
end
module ClassMethods
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def property(name, *options, &block)
opts = { }
type = options.shift
if type.class != Hash
opts[:type] = type
opts.merge!(options.shift || {})
else
opts.update(type)
end
existing_property = self.properties.find{|p| p.name == name.to_s}
if existing_property.nil? || (existing_property.default != opts[:default])
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define_property(name, opts, &block)
end
end
# Automatically set <tt>updated_at</tt> and <tt>created_at</tt> fields
# on the document whenever saving occurs. CouchRest uses a pretty
# decent time format by default. See Time#to_json
def timestamps!
class_eval <<-EOS, __FILE__, __LINE__
property(:updated_at, Time, :read_only => true, :protected => true, :auto_validation => false)
property(:created_at, Time, :read_only => true, :protected => true, :auto_validation => false)
set_callback :save, :before do |object|
write_attribute('updated_at', Time.now)
write_attribute('created_at', Time.now) if object.new?
end
EOS
end
protected
# This is not a thread safe operation, if you have to set new properties at runtime
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# make sure a mutex is used.
def define_property(name, options={}, &block)
# check if this property is going to casted
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type = options.delete(:type) || options.delete(:cast_as)
if block_given?
type = Class.new(Hash) do
include CastedModel
end
if block.arity == 1 # Traditional, with options
type.class_eval { yield type }
else
type.instance_exec(&block)
end
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type = [type] # inject as an array
end
property = Property.new(name, type, options)
create_property_getter(property)
create_property_setter(property) unless property.read_only == true
if property.type_class.respond_to?(:validates_casted_model)
validates_casted_model property.name
end
properties << property
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property
end
# defines the getter for the property (and optional aliases)
def create_property_getter(property)
# meth = property.name
class_eval <<-EOS, __FILE__, __LINE__ + 1
def #{property.name}
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read_attribute('#{property.name}')
end
EOS
if ['boolean', TrueClass.to_s.downcase].include?(property.type.to_s.downcase)
class_eval <<-EOS, __FILE__, __LINE__
def #{property.name}?
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value = read_attribute('#{property.name}')
!(value.nil? || value == false)
end
EOS
end
if property.alias
class_eval <<-EOS, __FILE__, __LINE__ + 1
alias #{property.alias.to_sym} #{property.name.to_sym}
EOS
end
end
# defines the setter for the property (and optional aliases)
def create_property_setter(property)
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property_name = property.name
class_eval <<-EOS
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def #{property_name}=(value)
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write_attribute('#{property_name}', value)
end
EOS
if property.alias
class_eval <<-EOS
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alias #{property.alias.to_sym}= #{property_name.to_sym}=
EOS
end
end
end # module ClassMethods
end
end
end