+++ /dev/null
-module ActiveRecord
- module AttributeMethods #:nodoc:
- DEFAULT_SUFFIXES = %w(= ? _before_type_cast)
- ATTRIBUTE_TYPES_CACHED_BY_DEFAULT = [:datetime, :timestamp, :time, :date]
-
- def self.included(base)
- base.extend ClassMethods
- base.attribute_method_suffix(*DEFAULT_SUFFIXES)
- base.cattr_accessor :attribute_types_cached_by_default, :instance_writer => false
- base.attribute_types_cached_by_default = ATTRIBUTE_TYPES_CACHED_BY_DEFAULT
- base.cattr_accessor :time_zone_aware_attributes, :instance_writer => false
- base.time_zone_aware_attributes = false
- base.class_inheritable_accessor :skip_time_zone_conversion_for_attributes, :instance_writer => false
- base.skip_time_zone_conversion_for_attributes = []
- end
-
- # Declare and check for suffixed attribute methods.
- module ClassMethods
- # Declares a method available for all attributes with the given suffix.
- # Uses +method_missing+ and <tt>respond_to?</tt> to rewrite the method
- #
- # #{attr}#{suffix}(*args, &block)
- #
- # to
- #
- # attribute#{suffix}(#{attr}, *args, &block)
- #
- # An <tt>attribute#{suffix}</tt> instance method must exist and accept at least
- # the +attr+ argument.
- #
- # For example:
- #
- # class Person < ActiveRecord::Base
- # attribute_method_suffix '_changed?'
- #
- # private
- # def attribute_changed?(attr)
- # ...
- # end
- # end
- #
- # person = Person.find(1)
- # person.name_changed? # => false
- # person.name = 'Hubert'
- # person.name_changed? # => true
- def attribute_method_suffix(*suffixes)
- attribute_method_suffixes.concat suffixes
- rebuild_attribute_method_regexp
- end
-
- # Returns MatchData if method_name is an attribute method.
- def match_attribute_method?(method_name)
- rebuild_attribute_method_regexp unless defined?(@@attribute_method_regexp) && @@attribute_method_regexp
- @@attribute_method_regexp.match(method_name)
- end
-
-
- # Contains the names of the generated attribute methods.
- def generated_methods #:nodoc:
- @generated_methods ||= Set.new
- end
-
- def generated_methods?
- !generated_methods.empty?
- end
-
- # Generates all the attribute related methods for columns in the database
- # accessors, mutators and query methods.
- def define_attribute_methods
- return if generated_methods?
- columns_hash.each do |name, column|
- unless instance_method_already_implemented?(name)
- if self.serialized_attributes[name]
- define_read_method_for_serialized_attribute(name)
- elsif create_time_zone_conversion_attribute?(name, column)
- define_read_method_for_time_zone_conversion(name)
- else
- define_read_method(name.to_sym, name, column)
- end
- end
-
- unless instance_method_already_implemented?("#{name}=")
- if create_time_zone_conversion_attribute?(name, column)
- define_write_method_for_time_zone_conversion(name)
- else
- define_write_method(name.to_sym)
- end
- end
-
- unless instance_method_already_implemented?("#{name}?")
- define_question_method(name)
- end
- end
- end
-
- # Checks whether the method is defined in the model or any of its subclasses
- # that also derive from Active Record. Raises DangerousAttributeError if the
- # method is defined by Active Record though.
- def instance_method_already_implemented?(method_name)
- method_name = method_name.to_s
- return true if method_name =~ /^id(=$|\?$|$)/
- @_defined_class_methods ||= ancestors.first(ancestors.index(ActiveRecord::Base)).sum([]) { |m| m.public_instance_methods(false) | m.private_instance_methods(false) | m.protected_instance_methods(false) }.map(&:to_s).to_set
- @@_defined_activerecord_methods ||= (ActiveRecord::Base.public_instance_methods(false) | ActiveRecord::Base.private_instance_methods(false) | ActiveRecord::Base.protected_instance_methods(false)).map(&:to_s).to_set
- raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name)
- @_defined_class_methods.include?(method_name)
- end
-
- alias :define_read_methods :define_attribute_methods
-
- # +cache_attributes+ allows you to declare which converted attribute values should
- # be cached. Usually caching only pays off for attributes with expensive conversion
- # methods, like time related columns (e.g. +created_at+, +updated_at+).
- def cache_attributes(*attribute_names)
- attribute_names.each {|attr| cached_attributes << attr.to_s}
- end
-
- # Returns the attributes which are cached. By default time related columns
- # with datatype <tt>:datetime, :timestamp, :time, :date</tt> are cached.
- def cached_attributes
- @cached_attributes ||=
- columns.select{|c| attribute_types_cached_by_default.include?(c.type)}.map(&:name).to_set
- end
-
- # Returns +true+ if the provided attribute is being cached.
- def cache_attribute?(attr_name)
- cached_attributes.include?(attr_name)
- end
-
- private
- # Suffixes a, ?, c become regexp /(a|\?|c)$/
- def rebuild_attribute_method_regexp
- suffixes = attribute_method_suffixes.map { |s| Regexp.escape(s) }
- @@attribute_method_regexp = /(#{suffixes.join('|')})$/.freeze
- end
-
- # Default to =, ?, _before_type_cast
- def attribute_method_suffixes
- @@attribute_method_suffixes ||= []
- end
-
- def create_time_zone_conversion_attribute?(name, column)
- time_zone_aware_attributes && !skip_time_zone_conversion_for_attributes.include?(name.to_sym) && [:datetime, :timestamp].include?(column.type)
- end
-
- # Define an attribute reader method. Cope with nil column.
- def define_read_method(symbol, attr_name, column)
- cast_code = column.type_cast_code('v') if column
- access_code = cast_code ? "(v=@attributes['#{attr_name}']) && #{cast_code}" : "@attributes['#{attr_name}']"
-
- unless attr_name.to_s == self.primary_key.to_s
- access_code = access_code.insert(0, "missing_attribute('#{attr_name}', caller) unless @attributes.has_key?('#{attr_name}'); ")
- end
-
- if cache_attribute?(attr_name)
- access_code = "@attributes_cache['#{attr_name}'] ||= (#{access_code})"
- end
- evaluate_attribute_method attr_name, "def #{symbol}; #{access_code}; end"
- end
-
- # Define read method for serialized attribute.
- def define_read_method_for_serialized_attribute(attr_name)
- evaluate_attribute_method attr_name, "def #{attr_name}; unserialize_attribute('#{attr_name}'); end"
- end
-
- # Defined for all +datetime+ and +timestamp+ attributes when +time_zone_aware_attributes+ are enabled.
- # This enhanced read method automatically converts the UTC time stored in the database to the time zone stored in Time.zone.
- def define_read_method_for_time_zone_conversion(attr_name)
- method_body = <<-EOV
- def #{attr_name}(reload = false)
- cached = @attributes_cache['#{attr_name}']
- return cached if cached && !reload
- time = read_attribute('#{attr_name}')
- @attributes_cache['#{attr_name}'] = time.acts_like?(:time) ? time.in_time_zone : time
- end
- EOV
- evaluate_attribute_method attr_name, method_body
- end
-
- # Defines a predicate method <tt>attr_name?</tt>.
- def define_question_method(attr_name)
- evaluate_attribute_method attr_name, "def #{attr_name}?; query_attribute('#{attr_name}'); end", "#{attr_name}?"
- end
-
- def define_write_method(attr_name)
- evaluate_attribute_method attr_name, "def #{attr_name}=(new_value);write_attribute('#{attr_name}', new_value);end", "#{attr_name}="
- end
-
- # Defined for all +datetime+ and +timestamp+ attributes when +time_zone_aware_attributes+ are enabled.
- # This enhanced write method will automatically convert the time passed to it to the zone stored in Time.zone.
- def define_write_method_for_time_zone_conversion(attr_name)
- method_body = <<-EOV
- def #{attr_name}=(time)
- unless time.acts_like?(:time)
- time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
- end
- time = time.in_time_zone rescue nil if time
- write_attribute(:#{attr_name}, time)
- end
- EOV
- evaluate_attribute_method attr_name, method_body, "#{attr_name}="
- end
-
- # Evaluate the definition for an attribute related method
- def evaluate_attribute_method(attr_name, method_definition, method_name=attr_name)
-
- unless method_name.to_s == primary_key.to_s
- generated_methods << method_name
- end
-
- begin
- class_eval(method_definition, __FILE__, __LINE__)
- rescue SyntaxError => err
- generated_methods.delete(attr_name)
- if logger
- logger.warn "Exception occurred during reader method compilation."
- logger.warn "Maybe #{attr_name} is not a valid Ruby identifier?"
- logger.warn err.message
- end
- end
- end
- end # ClassMethods
-
-
- # Allows access to the object attributes, which are held in the <tt>@attributes</tt> hash, as though they
- # were first-class methods. So a Person class with a name attribute can use Person#name and
- # Person#name= and never directly use the attributes hash -- except for multiple assigns with
- # ActiveRecord#attributes=. A Milestone class can also ask Milestone#completed? to test that
- # the completed attribute is not +nil+ or 0.
- #
- # It's also possible to instantiate related objects, so a Client class belonging to the clients
- # table with a +master_id+ foreign key can instantiate master through Client#master.
- def method_missing(method_id, *args, &block)
- method_name = method_id.to_s
-
- if self.class.private_method_defined?(method_name)
- raise NoMethodError.new("Attempt to call private method", method_name, args)
- end
-
- # If we haven't generated any methods yet, generate them, then
- # see if we've created the method we're looking for.
- if !self.class.generated_methods?
- self.class.define_attribute_methods
- if self.class.generated_methods.include?(method_name)
- return self.send(method_id, *args, &block)
- end
- end
-
- if self.class.primary_key.to_s == method_name
- id
- elsif md = self.class.match_attribute_method?(method_name)
- attribute_name, method_type = md.pre_match, md.to_s
- if @attributes.include?(attribute_name)
- __send__("attribute#{method_type}", attribute_name, *args, &block)
- else
- super
- end
- elsif @attributes.include?(method_name)
- read_attribute(method_name)
- else
- super
- end
- end
-
- # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
- # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
- def read_attribute(attr_name)
- attr_name = attr_name.to_s
- if !(value = @attributes[attr_name]).nil?
- if column = column_for_attribute(attr_name)
- if unserializable_attribute?(attr_name, column)
- unserialize_attribute(attr_name)
- else
- column.type_cast(value)
- end
- else
- value
- end
- else
- nil
- end
- end
-
- def read_attribute_before_type_cast(attr_name)
- @attributes[attr_name]
- end
-
- # Returns true if the attribute is of a text column and marked for serialization.
- def unserializable_attribute?(attr_name, column)
- column.text? && self.class.serialized_attributes[attr_name]
- end
-
- # Returns the unserialized object of the attribute.
- def unserialize_attribute(attr_name)
- unserialized_object = object_from_yaml(@attributes[attr_name])
-
- if unserialized_object.is_a?(self.class.serialized_attributes[attr_name]) || unserialized_object.nil?
- @attributes.frozen? ? unserialized_object : @attributes[attr_name] = unserialized_object
- else
- raise SerializationTypeMismatch,
- "#{attr_name} was supposed to be a #{self.class.serialized_attributes[attr_name]}, but was a #{unserialized_object.class.to_s}"
- end
- end
-
-
- # Updates the attribute identified by <tt>attr_name</tt> with the specified +value+. Empty strings for fixnum and float
- # columns are turned into +nil+.
- def write_attribute(attr_name, value)
- attr_name = attr_name.to_s
- @attributes_cache.delete(attr_name)
- if (column = column_for_attribute(attr_name)) && column.number?
- @attributes[attr_name] = convert_number_column_value(value)
- else
- @attributes[attr_name] = value
- end
- end
-
-
- def query_attribute(attr_name)
- unless value = read_attribute(attr_name)
- false
- else
- column = self.class.columns_hash[attr_name]
- if column.nil?
- if Numeric === value || value !~ /[^0-9]/
- !value.to_i.zero?
- else
- return false if ActiveRecord::ConnectionAdapters::Column::FALSE_VALUES.include?(value)
- !value.blank?
- end
- elsif column.number?
- !value.zero?
- else
- !value.blank?
- end
- end
- end
-
- # A Person object with a name attribute can ask <tt>person.respond_to?(:name)</tt>,
- # <tt>person.respond_to?(:name=)</tt>, and <tt>person.respond_to?(:name?)</tt>
- # which will all return +true+.
- alias :respond_to_without_attributes? :respond_to?
- def respond_to?(method, include_private_methods = false)
- method_name = method.to_s
- if super
- return true
- elsif !include_private_methods && super(method, true)
- # If we're here than we haven't found among non-private methods
- # but found among all methods. Which means that given method is private.
- return false
- elsif !self.class.generated_methods?
- self.class.define_attribute_methods
- if self.class.generated_methods.include?(method_name)
- return true
- end
- end
-
- if @attributes.nil?
- return super
- elsif @attributes.include?(method_name)
- return true
- elsif md = self.class.match_attribute_method?(method_name)
- return true if @attributes.include?(md.pre_match)
- end
- super
- end
-
- private
-
- def missing_attribute(attr_name, stack)
- raise ActiveRecord::MissingAttributeError, "missing attribute: #{attr_name}", stack
- end
-
- # Handle *? for method_missing.
- def attribute?(attribute_name)
- query_attribute(attribute_name)
- end
-
- # Handle *= for method_missing.
- def attribute=(attribute_name, value)
- write_attribute(attribute_name, value)
- end
-
- # Handle *_before_type_cast for method_missing.
- def attribute_before_type_cast(attribute_name)
- read_attribute_before_type_cast(attribute_name)
- end
- end
-end
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