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Merge pull request #6211 from frodsan/docs_attr_accessor_32stable

Adding docs to attribute accessor methods.
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2 parents b12d03d + 96fe0af commit ad4d4088c49be013c2248b1cf2ca92b074e8ac03 @vijaydev vijaydev committed May 8, 2012
Showing with 111 additions and 0 deletions.
  1. +111 −0 activesupport/lib/active_support/core_ext/class/attribute_accessors.rb
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111 activesupport/lib/active_support/core_ext/class/attribute_accessors.rb
@@ -26,6 +26,32 @@
# Person.new.hair_colors = [:brown] # => NoMethodError
# Person.new.hair_colors # => NoMethodError
class Class
+ # Defines a class attribute if it's not defined and creates a reader method that
+ # returns the attribute value.
+ #
+ # class Person
+ # cattr_reader :hair_colors
+ # end
+ #
+ # Person.class_variable_set("@@hair_colors", [:brown, :black])
+ # Person.hair_colors # => [:brown, :black]
+ # Person.new.hair_colors # => [:brown, :black]
+ #
+ # The attribute name must be a valid method name in Ruby.
+ #
+ # class Person
+ # cattr_reader :"1_Badname "
+ # end
+ # # => NameError: invalid attribute name
+ #
+ # If you want to opt out the instance reader method, you can pass <tt>instance_reader: false</tt>
+ # or <tt>instance_accessor: false</tt>.
+ #
+ # class Person
+ # cattr_reader :hair_colors, instance_reader: false
+ # end
+ #
+ # Person.new.hair_colors # => NoMethodError
def cattr_reader(*syms)
options = syms.extract_options!
syms.each do |sym|
@@ -49,6 +75,43 @@ def #{sym}
end
end
+ # Defines a class attribute if it's not defined and creates a writer method to allow
+ # assignment to the attribute.
+ #
+ # class Person
+ # cattr_writer :hair_colors
+ # end
+ #
+ # Person.hair_colors = [:brown, :black]
+ # Person.class_variable_get("@@hair_colors") # => [:brown, :black]
+ # Person.new.hair_colors = [:blonde, :red]
+ # Person.class_variable_get("@@hair_colors") # => [:blonde, :red]
+ #
+ # The attribute name must be a valid method name in Ruby.
+ #
+ # class Person
+ # cattr_writer :"1_Badname "
+ # end
+ # # => NameError: invalid attribute name
+ #
+ # If you want to opt out the instance writer method, pass <tt>instance_writer: false</tt>
+ # or <tt>instance_accessor: false</tt>.
+ #
+ # class Person
+ # cattr_writer :hair_colors, instance_writer: false
+ # end
+ #
+ # Person.new.hair_colors = [:blonde, :red] # => NoMethodError
+ #
+ # Also, you can pass a block to set up the attribute with a default value.
+ #
+ # class Person
+ # cattr_writer :hair_colors do
+ # [:brown, :black, :blonde, :red]
+ # end
+ # end
+ #
+ # Person.class_variable_get("@@hair_colors") # => [:brown, :black, :blonde, :red]
def cattr_writer(*syms)
options = syms.extract_options!
syms.each do |sym|
@@ -73,6 +136,54 @@ def #{sym}=(obj)
end
end
+ # Defines both class and instance accessors for class attributes.
+ #
+ # class Person
+ # cattr_accessor :hair_colors
+ # end
+ #
+ # Person.hair_colors = [:brown, :black, :blonde, :red]
+ # Person.hair_colors # => [:brown, :black, :blonde, :red]
+ # Person.new.hair_colors # => [:brown, :black, :blonde, :red]
+ #
+ # If a subclass changes the value then that would also change the value for
+ # parent class. Similarly if parent class changes the value then that would
+ # change the value of subclasses too.
+ #
+ # class Male < Person
+ # end
+ #
+ # Male.hair_colors << :blue
+ # Person.hair_colors # => [:brown, :black, :blonde, :red, :blue]
+ #
+ # To opt out of the instance writer method, pass <tt>instance_writer: false</tt>.
+ # To opt out of the instance reader method, pass <tt>instance_reader: false</tt>.
+ #
+ # class Person
+ # cattr_accessor :hair_colors, instance_writer: false, instance_reader: false
+ # end
+ #
+ # Person.new.hair_colors = [:brown] # => NoMethodError
+ # Person.new.hair_colors # => NoMethodError
+ #
+ # Or pass <tt>instance_accessor: false</tt>, to opt out both instance methods.
+ #
+ # class Person
+ # cattr_accessor :hair_colors, instance_accessor: false
+ # end
+ #
+ # Person.new.hair_colors = [:brown] # => NoMethodError
+ # Person.new.hair_colors # => NoMethodError
+ #
+ # Also you can pass a block to set up the attribute with a default value.
+ #
+ # class Person
+ # cattr_accessor :hair_colors do
+ # [:brown, :black, :blonde, :red]
+ # end
+ # end
+ #
+ # Person.class_variable_get("@@hair_colors") #=> [:brown, :black, :blonde, :red]
def cattr_accessor(*syms, &blk)
cattr_reader(*syms)
cattr_writer(*syms, &blk)

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