class Decay::Metaprogramming

Public Class Methods

new(class:, enumerated_type:, enumerated_type_name:) click to toggle source
# File lib/decay/metaprogramming.rb, line 3
def initialize(class:, enumerated_type:, enumerated_type_name:)
  @klass = binding.local_variable_get(:class)
  @enumerated_type = enumerated_type
  @enumerated_type_name = enumerated_type_name
end

Public Instance Methods

define_active_record_attribute() click to toggle source
# File lib/decay/metaprogramming.rb, line 71
def define_active_record_attribute
  @klass.attribute @enumerated_type_name, \
    Decay::ActiveEnumAttribute.new(enum: @enumerated_type)
end
define_active_record_bang_setters() click to toggle source
# File lib/decay/metaprogramming.rb, line 76
def define_active_record_bang_setters
  enumerated_type_name = @enumerated_type_name

  @enumerated_type.each do |key, _value|
    if key.nil?
      next
    end

    assert_instance_conflict_free("#{key}!")
    @klass.send(:define_method, "#{key}!") do
      send("#{enumerated_type_name}=", key)
    end
  end
end
define_active_record_question_getters() click to toggle source
# File lib/decay/metaprogramming.rb, line 91
def define_active_record_question_getters
  enumerated_type_name = @enumerated_type_name

  @enumerated_type.each do |key, value|
    if key.nil?
      next
    end

    assert_instance_conflict_free("#{key}?")
    @klass.send(:define_method, "#{key}?") do
      send(enumerated_type_name) == value
    end
  end
end
define_active_record_scopes() click to toggle source
# File lib/decay/metaprogramming.rb, line 106
def define_active_record_scopes
  enumerated_type_name = @enumerated_type_name

  @enumerated_type.each do |key, value|
    if key
      assert_scope_conflict_free(key)
      @klass.scope key, -> { where(enumerated_type_name => value.value) }
    end
  end
end
define_bang_setters() click to toggle source
# File lib/decay/metaprogramming.rb, line 41
def define_bang_setters
  enumerated_type_name = @enumerated_type_name

  @enumerated_type.each do |key, value|
    if key.nil?
      next
    end

    assert_instance_conflict_free("#{key}!")
    @klass.send(:define_method, "#{key}!") do
      instance_variable_set("@#{enumerated_type_name}", value)
    end
  end
end
define_enumerated_type() click to toggle source
# File lib/decay/metaprogramming.rb, line 9
def define_enumerated_type
  @klass.const_set(@enumerated_type_name.to_s.upcase, @enumerated_type)
end
define_getter() click to toggle source
# File lib/decay/metaprogramming.rb, line 13
def define_getter
  enumerated_type_name = @enumerated_type_name

  assert_instance_conflict_free(enumerated_type_name)
  @klass.send(:define_method, enumerated_type_name) do
    instance_variable_get("@#{enumerated_type_name}")
  end
end
define_question_getters() click to toggle source
# File lib/decay/metaprogramming.rb, line 56
def define_question_getters
  enumerated_type_name = @enumerated_type_name

  @enumerated_type.each do |key, value|
    if key.nil?
      next
    end

    assert_instance_conflict_free("#{key}?")
    @klass.send(:define_method, "#{key}?") do
      instance_variable_get("@#{enumerated_type_name}") == value
    end
  end
end
define_setter() click to toggle source
# File lib/decay/metaprogramming.rb, line 22
def define_setter
  enumerated_type = @enumerated_type
  enumerated_type_name = @enumerated_type_name

  assert_instance_conflict_free("#{enumerated_type_name}=")
  @klass.send(:define_method, "#{enumerated_type_name}=") do |new_value|
    value =
      if new_value.respond_to?(:to_sym)
        new_value.to_sym
      else
        new_value
      end

    enum = enumerated_type[value]

    instance_variable_set("@#{enumerated_type_name}", enum)
  end
end

Private Instance Methods

assert_instance_conflict_free(method_name) click to toggle source
# File lib/decay/metaprogramming.rb, line 119
def assert_instance_conflict_free(method_name)
  if @klass.instance_methods.include?(method_name.to_sym)
    previously_defined_method = @klass.instance_method(method_name)
    filename, lineno = previously_defined_method.source_location

    raise Error::EnumConflict, \
      "Instance method `#{method_name}` was previously defined " \
      "in #{filename}:#{lineno}"
  end
end
assert_scope_conflict_free(method_name) click to toggle source
# File lib/decay/metaprogramming.rb, line 130
def assert_scope_conflict_free(method_name)
  if @klass.methods.include?(method_name.to_sym)
    previously_defined_method = @klass.method(method_name)
    filename, lineno = previously_defined_method.source_location

    raise Error::EnumConflict, \
      "Scope `#{method_name}` was previously defined " \
      "in #{filename}:#{lineno}"
  end
end