Method: Module#thread_mattr_writer

Defined in:
activesupport/lib/active_support/core_ext/module/attribute_accessors_per_thread.rb

#thread_mattr_writer(*syms, instance_writer: true, instance_accessor: true) ⇒ Object Also known as: thread_cattr_writer

Defines a per-thread class attribute and creates a class and instance writer methods to allow assignment to the attribute.

module Current
  thread_mattr_writer :user
end

Current.user = "DHH"
Thread.current[:attr_Current_user] # => "DHH"

To omit the instance writer method, pass instance_writer: false or instance_accessor: false.

class Current
  thread_mattr_writer :user, instance_writer: false
end

Current.new.user = "DHH" # => NoMethodError



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# File 'activesupport/lib/active_support/core_ext/module/attribute_accessors_per_thread.rb', line 101

def thread_mattr_writer(*syms, instance_writer: true, instance_accessor: true) # :nodoc:
  syms.each do |sym|
    raise NameError.new("invalid attribute name: #{sym}") unless /^[_A-Za-z]\w*$/.match?(sym)

    # The following generated method concatenates `object_id` because we want
    # subclasses to maintain independent values.
    class_eval("      def self.\#{sym}=(obj)\n        @__thread_mattr_\#{sym} ||= \"attr_\#{sym}_\\\#{object_id}\"\n        ::ActiveSupport::IsolatedExecutionState[@__thread_mattr_\#{sym}] = obj\n      end\n    EOS\n\n    if instance_writer && instance_accessor\n      class_eval(<<-EOS, __FILE__, __LINE__ + 1)\n        def \#{sym}=(obj)\n          self.class.\#{sym} = obj\n        end\n      EOS\n    end\n  end\nend\n", __FILE__, __LINE__ + 1)