Module: EnumerableConstants

Defined in:
lib/enumerable_constants.rb,
lib/enumerable_constants/version.rb

Overview

This module can be used for situations where enumerating over constant values is desired. This facilitates keeping the code DRY by keeping the constant values defined in one place, and still having the ability to enumerate over their values wherever they are needed.

## Example use cases

  • defining constants for possible field values in an AR object while using the values in a ‘validates_inclusion_of` validation

  • defining constants for select box values in a view helper and using this module to allow them to be enumerated over in the select tag

Constant Summary collapse

VERSION = 
"0.0.1"

Class Method Summary collapse

Class Method Details

.included(mod) ⇒ Object 



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# File 'lib/enumerable_constants.rb', line 14

def EnumerableConstants.included(mod)
  class << mod
    include Enumerable

    def enumerable(*consts)
      @enumerable_consts = consts unless consts.empty?
    end

    # Yields each constant value to &block.  By default, all constants defined by the
    # including class are yielded.  If specific constants are to be yielded, call 
    # EnumerableConstants#enumerable(*consts) before calling this method.

    def each(&block)
      consts = @enumerable_consts || self.constants.grep(/[^a-z][A-Z_]+/)
      consts.each do |const|
        yield self.const_get(const)
      end
    end

    # #each_constant is provided as syntactic sugar for situations where it may be more appropriate than #each
    alias_method :each_constant, :each
  end
end