Class: Class
- Defined in:
- lib/active_support/core_ext/class/removal.rb,
lib/active_support/dependencies.rb,
lib/active_support/core_ext/class/attribute_accessors.rb,
lib/active_support/core_ext/class/delegating_attributes.rb,
lib/active_support/core_ext/class/inheritable_attributes.rb
Overview
Allows attributes to be shared within an inheritance hierarchy, but where each descendant gets a copy of their parents’ attributes, instead of just a pointer to the same. This means that the child can add elements to, for example, an array without those additions being shared with either their parent, siblings, or children, which is unlike the regular class-level attributes that are shared across the entire hierarchy.
Constant Summary collapse
- EMPTY_INHERITABLE_ATTRIBUTES =
Prevent this constant from being created multiple times
{}.freeze
Instance Method Summary collapse
- #cattr_accessor(*syms) ⇒ Object
-
#cattr_reader(*syms) ⇒ Object
:nodoc:.
- #cattr_writer(*syms) ⇒ Object
- #class_inheritable_accessor(*syms) ⇒ Object
- #class_inheritable_array(*syms) ⇒ Object
- #class_inheritable_array_writer(*syms) ⇒ Object
- #class_inheritable_hash(*syms) ⇒ Object
- #class_inheritable_hash_writer(*syms) ⇒ Object
-
#class_inheritable_reader(*syms) ⇒ Object
:nodoc:.
- #class_inheritable_writer(*syms) ⇒ Object
- #const_missing(class_id) ⇒ Object
- #inheritable_attributes ⇒ Object
- #read_inheritable_attribute(key) ⇒ Object
- #remove_class(*klasses) ⇒ Object
- #remove_subclasses ⇒ Object
- #reset_inheritable_attributes ⇒ Object
- #subclasses ⇒ Object
- #superclass_delegating_accessor(*names) ⇒ Object
- #superclass_delegating_reader(*names) ⇒ Object
- #superclass_delegating_writer(*names) ⇒ Object
- #write_inheritable_array(key, elements) ⇒ Object
- #write_inheritable_attribute(key, value) ⇒ Object
- #write_inheritable_hash(key, hash) ⇒ Object
Instance Method Details
#cattr_accessor(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/attribute_accessors.rb', line 44 def cattr_accessor(*syms) cattr_reader(*syms) cattr_writer(*syms) end |
#cattr_reader(*syms) ⇒ Object
:nodoc:
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# File 'lib/active_support/core_ext/class/attribute_accessors.rb', line 4 def cattr_reader(*syms) syms.flatten.each do |sym| next if sym.is_a?(Hash) class_eval(<<-EOS, __FILE__, __LINE__) unless defined? @@#{sym} @@#{sym} = nil end def self.#{sym} @@#{sym} end def #{sym} @@#{sym} end EOS end end |
#cattr_writer(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/attribute_accessors.rb', line 23 def cattr_writer(*syms) = syms. syms.flatten.each do |sym| class_eval(<<-EOS, __FILE__, __LINE__) unless defined? @@#{sym} @@#{sym} = nil end def self.#{sym}=(obj) @@#{sym} = obj end #{" def #{sym}=(obj) @@#{sym} = obj end " unless [:instance_writer] == false } EOS end end |
#class_inheritable_accessor(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 76 def class_inheritable_accessor(*syms) class_inheritable_reader(*syms) class_inheritable_writer(*syms) end |
#class_inheritable_array(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 81 def class_inheritable_array(*syms) class_inheritable_reader(*syms) class_inheritable_array_writer(*syms) end |
#class_inheritable_array_writer(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 42 def class_inheritable_array_writer(*syms) = syms. syms.each do |sym| class_eval <<-EOS def self.#{sym}=(obj) write_inheritable_array(:#{sym}, obj) end #{" def #{sym}=(obj) self.class.#{sym} = obj end " unless [:instance_writer] == false } EOS end end |
#class_inheritable_hash(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 86 def class_inheritable_hash(*syms) class_inheritable_reader(*syms) class_inheritable_hash_writer(*syms) end |
#class_inheritable_hash_writer(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 59 def class_inheritable_hash_writer(*syms) = syms. syms.each do |sym| class_eval <<-EOS def self.#{sym}=(obj) write_inheritable_hash(:#{sym}, obj) end #{" def #{sym}=(obj) self.class.#{sym} = obj end " unless [:instance_writer] == false } EOS end end |
#class_inheritable_reader(*syms) ⇒ Object
:nodoc:
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 10 def class_inheritable_reader(*syms) syms.each do |sym| next if sym.is_a?(Hash) class_eval <<-EOS def self.#{sym} read_inheritable_attribute(:#{sym}) end def #{sym} self.class.#{sym} end EOS end end |
#class_inheritable_writer(*syms) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 25 def class_inheritable_writer(*syms) = syms. syms.each do |sym| class_eval <<-EOS def self.#{sym}=(obj) write_inheritable_attribute(:#{sym}, obj) end #{" def #{sym}=(obj) self.class.#{sym} = obj end " unless [:instance_writer] == false } EOS end end |
#const_missing(class_id) ⇒ Object
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# File 'lib/active_support/dependencies.rb', line 463 def const_missing(class_id) if [Object, Kernel].include?(self) || parent == self super else begin begin Dependencies.load_missing_constant self, class_id rescue NameError parent.send :const_missing, class_id end rescue NameError => e # Make sure that the name we are missing is the one that caused the error parent_qualified_name = Dependencies.qualified_name_for parent, class_id raise unless e.missing_name? parent_qualified_name qualified_name = Dependencies.qualified_name_for self, class_id raise NameError.new("uninitialized constant #{qualified_name}").copy_blame!(e) end end end |
#inheritable_attributes ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 91 def inheritable_attributes @inheritable_attributes ||= EMPTY_INHERITABLE_ATTRIBUTES end |
#read_inheritable_attribute(key) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 112 def read_inheritable_attribute(key) inheritable_attributes[key] end |
#remove_class(*klasses) ⇒ Object
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# File 'lib/active_support/core_ext/class/removal.rb', line 10 def remove_class(*klasses) klasses.flatten.each do |klass| # Skip this class if there is nothing bound to this name next unless defined?(klass.name) basename = klass.to_s.split("::").last parent = klass.parent # Skip this class if it does not match the current one bound to this name next unless parent.const_defined?(basename) && klass = parent.const_get(basename) parent.instance_eval { remove_const basename } unless parent == klass end end |
#remove_subclasses ⇒ Object
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# File 'lib/active_support/core_ext/class/removal.rb', line 2 def remove_subclasses Object.remove_subclasses_of(self) end |
#reset_inheritable_attributes ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 116 def reset_inheritable_attributes @inheritable_attributes = EMPTY_INHERITABLE_ATTRIBUTES end |
#subclasses ⇒ Object
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# File 'lib/active_support/core_ext/class/removal.rb', line 6 def subclasses Object.subclasses_of(self).map { |o| o.to_s } end |
#superclass_delegating_accessor(*names) ⇒ Object
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# File 'lib/active_support/core_ext/class/delegating_attributes.rb', line 36 def superclass_delegating_accessor(*names) superclass_delegating_reader(*names) superclass_delegating_writer(*names) end |
#superclass_delegating_reader(*names) ⇒ Object
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# File 'lib/active_support/core_ext/class/delegating_attributes.rb', line 8 def superclass_delegating_reader(*names) class_name_to_stop_searching_on = self.superclass.name.blank? ? "Object" : self.superclass.name names.each do |name| class_eval <<-EOS def self.#{name} if defined?(@#{name}) @#{name} elsif superclass < #{class_name_to_stop_searching_on} && superclass.respond_to?(:#{name}) superclass.#{name} end end def #{name} self.class.#{name} end EOS end end |
#superclass_delegating_writer(*names) ⇒ Object
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# File 'lib/active_support/core_ext/class/delegating_attributes.rb', line 26 def superclass_delegating_writer(*names) names.each do |name| class_eval <<-EOS def self.#{name}=(value) @#{name} = value end EOS end end |
#write_inheritable_array(key, elements) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 102 def write_inheritable_array(key, elements) write_inheritable_attribute(key, []) if read_inheritable_attribute(key).nil? write_inheritable_attribute(key, read_inheritable_attribute(key) + elements) end |
#write_inheritable_attribute(key, value) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 95 def write_inheritable_attribute(key, value) if inheritable_attributes.equal?(EMPTY_INHERITABLE_ATTRIBUTES) @inheritable_attributes = {} end inheritable_attributes[key] = value end |
#write_inheritable_hash(key, hash) ⇒ Object
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# File 'lib/active_support/core_ext/class/inheritable_attributes.rb', line 107 def write_inheritable_hash(key, hash) write_inheritable_attribute(key, {}) if read_inheritable_attribute(key).nil? write_inheritable_attribute(key, read_inheritable_attribute(key).merge(hash)) end |