diff options
Diffstat (limited to 'activerecord/lib/active_record/attribute_methods.rb')
| -rw-r--r-- | activerecord/lib/active_record/attribute_methods.rb | 263 |
1 files changed, 162 insertions, 101 deletions
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb index e0bfdb8f3e..83fcefa64d 100644 --- a/activerecord/lib/active_record/attribute_methods.rb +++ b/activerecord/lib/active_record/attribute_methods.rb @@ -1,4 +1,7 @@ require 'active_support/core_ext/enumerable' +require 'active_support/core_ext/string/filters' +require 'mutex_m' +require 'thread_safe' module ActiveRecord # = Active Record Attribute Methods @@ -7,6 +10,7 @@ module ActiveRecord include ActiveModel::AttributeMethods included do + initialize_generated_modules include Read include Write include BeforeTypeCast @@ -15,29 +19,81 @@ module ActiveRecord include TimeZoneConversion include Dirty include Serialization + + delegate :column_for_attribute, to: :class end + AttrNames = Module.new { + def self.set_name_cache(name, value) + const_name = "ATTR_#{name}" + unless const_defined? const_name + const_set const_name, value.dup.freeze + end + end + } + + BLACKLISTED_CLASS_METHODS = %w(private public protected allocate new name parent superclass) + + class AttributeMethodCache + def initialize + @module = Module.new + @method_cache = ThreadSafe::Cache.new + end + + def [](name) + @method_cache.compute_if_absent(name) do + safe_name = name.unpack('h*').first + temp_method = "__temp__#{safe_name}" + ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name + @module.module_eval method_body(temp_method, safe_name), __FILE__, __LINE__ + @module.instance_method temp_method + end + end + + private + + # Override this method in the subclasses for method body. + def method_body(method_name, const_name) + raise NotImplementedError, "Subclasses must implement a method_body(method_name, const_name) method." + end + end + + class GeneratedAttributeMethods < Module; end # :nodoc: + module ClassMethods + def inherited(child_class) #:nodoc: + child_class.initialize_generated_modules + super + end + + def initialize_generated_modules # :nodoc: + @generated_attribute_methods = GeneratedAttributeMethods.new { extend Mutex_m } + @attribute_methods_generated = false + include @generated_attribute_methods + + super + end + # Generates all the attribute related methods for columns in the database # accessors, mutators and query methods. def define_attribute_methods # :nodoc: - # Use a mutex; we don't want two thread simaltaneously trying to define + return false if @attribute_methods_generated + # Use a mutex; we don't want two threads simultaneously trying to define # attribute methods. - @attribute_methods_mutex.synchronize do - return if attribute_methods_generated? + generated_attribute_methods.synchronize do + return false if @attribute_methods_generated superclass.define_attribute_methods unless self == base_class super(column_names) @attribute_methods_generated = true end - end - - def attribute_methods_generated? # :nodoc: - @attribute_methods_generated ||= false + true end def undefine_attribute_methods # :nodoc: - super if attribute_methods_generated? - @attribute_methods_generated = false + generated_attribute_methods.synchronize do + super if defined?(@attribute_methods_generated) && @attribute_methods_generated + @attribute_methods_generated = false + end end # Raises a <tt>ActiveRecord::DangerousAttributeError</tt> exception when an @@ -56,28 +112,48 @@ module ActiveRecord # # => false def instance_method_already_implemented?(method_name) if dangerous_attribute_method?(method_name) - raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" + raise DangerousAttributeError, "#{method_name} is defined by Active Record. Check to make sure that you don't have an attribute or method with the same name." end if superclass == Base super else - # If B < A and A defines its own attribute method, then we don't want to overwrite that. - defined = method_defined_within?(method_name, superclass, superclass.generated_attribute_methods) - defined && !ActiveRecord::Base.method_defined?(method_name) || super + # If ThisClass < ... < SomeSuperClass < ... < Base and SomeSuperClass + # defines its own attribute method, then we don't want to overwrite that. + defined = method_defined_within?(method_name, superclass, Base) && + ! superclass.instance_method(method_name).owner.is_a?(GeneratedAttributeMethods) + defined || super end end - # A method name is 'dangerous' if it is already defined by Active Record, but + # A method name is 'dangerous' if it is already (re)defined by Active Record, but # not by any ancestors. (So 'puts' is not dangerous but 'save' is.) def dangerous_attribute_method?(name) # :nodoc: method_defined_within?(name, Base) end - def method_defined_within?(name, klass, sup = klass.superclass) # :nodoc: + def method_defined_within?(name, klass, superklass = klass.superclass) # :nodoc: if klass.method_defined?(name) || klass.private_method_defined?(name) - if sup.method_defined?(name) || sup.private_method_defined?(name) - klass.instance_method(name).owner != sup.instance_method(name).owner + if superklass.method_defined?(name) || superklass.private_method_defined?(name) + klass.instance_method(name).owner != superklass.instance_method(name).owner + else + true + end + else + false + end + end + + # A class method is 'dangerous' if it is already (re)defined by Active Record, but + # not by any ancestors. (So 'puts' is not dangerous but 'new' is.) + def dangerous_class_method?(method_name) + BLACKLISTED_CLASS_METHODS.include?(method_name.to_s) || class_method_defined_within?(method_name, Base) + end + + def class_method_defined_within?(name, klass, superklass = klass.superclass) # :nodoc + if klass.respond_to?(name, true) + if superklass.respond_to?(name, true) + klass.method(name).owner != superklass.method(name).owner else true end @@ -114,41 +190,35 @@ module ActiveRecord [] end end - end - - # If we haven't generated any methods yet, generate them, then - # see if we've created the method we're looking for. - def method_missing(method, *args, &block) # :nodoc: - unless self.class.attribute_methods_generated? - self.class.define_attribute_methods - if respond_to_without_attributes?(method) - send(method, *args, &block) - else - super + # Returns the column object for the named attribute. + # Returns nil if the named attribute does not exist. + # + # class Person < ActiveRecord::Base + # end + # + # person = Person.new + # person.column_for_attribute(:name) # the result depends on the ConnectionAdapter + # # => #<ActiveRecord::ConnectionAdapters::Column:0x007ff4ab083980 @name="name", @sql_type="varchar(255)", @null=true, ...> + # + # person.column_for_attribute(:nothing) + # # => nil + def column_for_attribute(name) + column = columns_hash[name.to_s] + if column.nil? + ActiveSupport::Deprecation.warn(<<-MSG.squish) + `#column_for_attribute` will return a null object for non-existent + columns in Rails 5. Use `#has_attribute?` if you need to check for + an attribute's existence. + MSG end - else - super - end - end - - def attribute_missing(match, *args, &block) # :nodoc: - if self.class.columns_hash[match.attr_name] - ActiveSupport::Deprecation.warn( - "The method `#{match.method_name}', matching the attribute `#{match.attr_name}' has " \ - "dispatched through method_missing. This shouldn't happen, because `#{match.attr_name}' " \ - "is a column of the table. If this error has happened through normal usage of Active " \ - "Record (rather than through your own code or external libraries), please report it as " \ - "a bug." - ) + column end - - super 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+. It also define the attribute methods if they have + # which will all return +true+. It also defines the attribute methods if they have # not been generated. # # class Person < ActiveRecord::Base @@ -163,8 +233,18 @@ module ActiveRecord # person.respond_to('age?') # => true # person.respond_to(:nothing) # => false def respond_to?(name, include_private = false) - self.class.define_attribute_methods unless self.class.attribute_methods_generated? - super + return false unless super + name = name.to_s + + # If the result is true then check for the select case. + # For queries selecting a subset of columns, return false for unselected columns. + # We check defined?(@attributes) not to issue warnings if called on objects that + # have been allocated but not yet initialized. + if defined?(@attributes) && self.class.column_names.include?(name) + return has_attribute?(name) + end + + return true end # Returns +true+ if the given attribute is in the attributes hash, otherwise +false+. @@ -177,7 +257,7 @@ module ActiveRecord # person.has_attribute?('age') # => true # person.has_attribute?(:nothing) # => false def has_attribute?(attr_name) - @attributes.has_key?(attr_name.to_s) + @attributes.key?(attr_name.to_s) end # Returns an array of names for the attributes available on this object. @@ -201,31 +281,36 @@ module ActiveRecord # person.attributes # # => {"id"=>3, "created_at"=>Sun, 21 Oct 2012 04:53:04, "updated_at"=>Sun, 21 Oct 2012 04:53:04, "name"=>"Francesco", "age"=>22} def attributes - attribute_names.each_with_object({}) { |name, attrs| - attrs[name] = read_attribute(name) - } + @attributes.to_hash end # Returns an <tt>#inspect</tt>-like string for the value of the - # attribute +attr_name+. String attributes are truncated upto 50 - # characters, and Date and Time attributes are returned in the - # <tt>:db</tt> format. Other attributes return the value of - # <tt>#inspect</tt> without modification. + # attribute +attr_name+. String attributes are truncated up to 50 + # characters, Date and Time attributes are returned in the + # <tt>:db</tt> format, Array attributes are truncated up to 10 values. + # Other attributes return the value of <tt>#inspect</tt> without + # modification. # # person = Person.create!(name: 'David Heinemeier Hansson ' * 3) # # person.attribute_for_inspect(:name) - # # => "\"David Heinemeier Hansson David Heinemeier Hansson D...\"" + # # => "\"David Heinemeier Hansson David Heinemeier Hansson ...\"" # # person.attribute_for_inspect(:created_at) # # => "\"2012-10-22 00:15:07\"" + # + # person.attribute_for_inspect(:tag_ids) + # # => "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...]" def attribute_for_inspect(attr_name) value = read_attribute(attr_name) if value.is_a?(String) && value.length > 50 - "#{value[0..50]}...".inspect + "#{value[0, 50]}...".inspect elsif value.is_a?(Date) || value.is_a?(Time) %("#{value.to_s(:db)}") + elsif value.is_a?(Array) && value.size > 10 + inspected = value.first(10).inspect + %(#{inspected[0...-1]}, ...]) else value.inspect end @@ -239,39 +324,24 @@ module ActiveRecord # class Task < ActiveRecord::Base # end # - # person = Task.new(title: '', is_done: false) - # person.attribute_present?(:title) # => false - # person.attribute_present?(:is_done) # => true - # person.name = 'Francesco' - # person.is_done = true - # person.attribute_present?(:title) # => true - # person.attribute_present?(:is_done) # => true + # task = Task.new(title: '', is_done: false) + # task.attribute_present?(:title) # => false + # task.attribute_present?(:is_done) # => true + # task.title = 'Buy milk' + # task.is_done = true + # task.attribute_present?(:title) # => true + # task.attribute_present?(:is_done) # => true def attribute_present?(attribute) - value = read_attribute(attribute) + value = _read_attribute(attribute) !value.nil? && !(value.respond_to?(:empty?) && value.empty?) end - # Returns the column object for the named attribute. Returns +nil+ if the - # named attribute not exists. - # - # class Person < ActiveRecord::Base - # end - # - # person = Person.new - # person.column_for_attribute(:name) # the result depends on the ConnectionAdapter - # # => #<ActiveRecord::ConnectionAdapters::SQLite3Column:0x007ff4ab083980 @name="name", @sql_type="varchar(255)", @null=true, ...> - # - # person.column_for_attribute(:nothing) - # # => nil - def column_for_attribute(name) - # FIXME: should this return a null object for columns that don't exist? - self.class.columns_hash[name.to_s] - 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)). It raises + # "2004-12-12" in a date column is cast to a date object, like Date.new(2004, 12, 12)). It raises # <tt>ActiveModel::MissingAttributeError</tt> if the identified attribute is missing. # + # Note: +:id+ is always present. + # # Alias for the <tt>read_attribute</tt> method. # # class Person < ActiveRecord::Base @@ -305,13 +375,6 @@ module ActiveRecord protected - def clone_attributes(reader_method = :read_attribute, attributes = {}) # :nodoc: - attribute_names.each do |name| - attributes[name] = clone_attribute_value(reader_method, name) - end - attributes - end - def clone_attribute_value(reader_method, attribute_name) # :nodoc: value = send(reader_method, attribute_name) value.duplicable? ? value.clone : value @@ -328,13 +391,14 @@ module ActiveRecord end def attribute_method?(attr_name) # :nodoc: - defined?(@attributes) && @attributes.include?(attr_name) + # We check defined? because Syck calls respond_to? before actually calling initialize. + defined?(@attributes) && @attributes.key?(attr_name) end private # Returns a Hash of the Arel::Attributes and attribute values that have been - # type casted for use in an Arel insert/update method. + # typecasted for use in an Arel insert/update method. def arel_attributes_with_values(attribute_names) attrs = {} arel_table = self.class.arel_table @@ -347,16 +411,16 @@ module ActiveRecord # Filters the primary keys and readonly attributes from the attribute names. def attributes_for_update(attribute_names) - attribute_names.select do |name| - column_for_attribute(name) && !pk_attribute?(name) && !readonly_attribute?(name) + attribute_names.reject do |name| + readonly_attribute?(name) end end # Filters out the primary keys, from the attribute names, when the primary # key is to be generated (e.g. the id attribute has no value). def attributes_for_create(attribute_names) - attribute_names.select do |name| - column_for_attribute(name) && !(pk_attribute?(name) && id.nil?) + attribute_names.reject do |name| + pk_attribute?(name) && id.nil? end end @@ -365,14 +429,11 @@ module ActiveRecord end def pk_attribute?(name) - column_for_attribute(name).primary + name == self.class.primary_key end def typecasted_attribute_value(name) - # FIXME: we need @attributes to be used consistently. - # If the values stored in @attributes were already typecasted, this code - # could be simplified - read_attribute(name) + _read_attribute(name) end end end |