Module: ScopedEnum::ClassMethods

Defined in:
lib/scoped_enum.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(base) ⇒ Object 



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# File 'lib/scoped_enum.rb', line 9

def self.extended(base)
  base.class_attribute(:defined_enum_scopes)
  base.defined_enum_scopes = HashWithIndifferentAccess.new
end

Instance Method Details

#scoped_enum(enum_name, enum_entries, scopes = {}) ⇒ Object 



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

def scoped_enum(enum_name, enum_entries, scopes = {})
  enum(enum_name => enum_entries)
  scopes = HashWithIndifferentAccess.new_from_hash_copying_default(scopes)

  target_enum = defined_enums[enum_name.to_s]
  scopes.each do |scope_name, scope_enum_keys|
    sub_enum_values = target_enum.values_at(*scope_enum_keys)
    if defined_enum_scopes.has_key?(scope_name)
      fail ArgumentError,
           "Conflicting scope names. A scope named #{scope_name} has already been defined"
    elsif sub_enum_values.include?(nil)
      unknown_key = scope_enum_keys[sub_enum_values.index(nil)]
      fail ArgumentError, "Unknown key - #{unknown_key} for enum #{enum_name}"
    elsif respond_to?(scope_name.to_s.pluralize)
      fail ArgumentError,
           "Scope name - #{scope_name} conflicts with a class method of the same name"
    elsif instance_methods.include?("#{scope_name}?".to_sym)
      fail ArgumentError,
           "Scope name - #{scope_name} conflicts with the instance method - #{scope_name}?"
    end

    sub_enum_entries = target_enum.slice(*scope_enum_keys)
    defined_enum_scopes[scope_name] = sub_enum_entries

    # 1. Instance method <scope_name>?
    define_method("#{scope_name}?") do
      sub_enum_entries.include? self.role
    end

    # 2. The class scope with the scope name
    scope scope_name.to_s.pluralize, -> { where("#{enum_name}" => sub_enum_entries.values) }
  end
  # 3. The class method to return all scopes of the enum
  singleton_class.send(:define_method, "#{enum_name}_scopes") { defined_enum_scopes.slice(*scopes.keys) }
end