module HasUniqueAttribute

Constants

VERSION

Public Instance Methods

has_unique_attribute(attribute_name, index: default_index_name_for_attribute(attribute_name), message: :taken) click to toggle source

@param attribute_name [String] @param index [String] @param message [Symbol, String] @return [void]

# File lib/has_unique_attribute.rb, line 8
def has_unique_attribute(attribute_name, # rubocop:disable Naming/PredicateName
                         index:   default_index_name_for_attribute(attribute_name),
                         message: :taken)
  assert_unique_index_defined!(index)

  handle_unique_attribute_on_save(attribute_name, index, message)
  handle_unique_attribute_on_save!(attribute_name, index, message)
end

Private Instance Methods

assert_unique_index_defined!(index_name) click to toggle source

@param index_name [String] @return [void]

# File lib/has_unique_attribute.rb, line 21
def assert_unique_index_defined!(index_name)
  index = connection.indexes(table_name).find { |index_definition| index_definition.name == index_name }

  raise ArgumentError, "#{name} does not have index: `#{index_name}`" if index.nil?
  raise ArgumentError, "#{name} defines an index `#{index_name}`, but it is not unique" unless index.unique
end

default_index_name_for_attribute(attribute_name) click to toggle source

@param attribute_name [String] @return [String]

# File lib/has_unique_attribute.rb, line 30
def default_index_name_for_attribute(attribute_name)
  "index_#{table_name}_on_#{attribute_name}"
end

handle_unique_attribute_on_save(attribute_name, index_name, message) click to toggle source

@param attribute_name [String] @param index_name [String] @param message [Symbol, String] @return [void]

# File lib/has_unique_attribute.rb, line 38
def handle_unique_attribute_on_save(attribute_name, index_name, message)
  existing_method = instance_method(:save)

  define_method(:save) do |*args, **kwargs|
    existing_method.bind(self).call(*args, **kwargs)
  rescue ActiveRecord::RecordNotUnique => error
    if error.message.include?(index_name)
      errors.add(attribute_name, message)

      return false
    end

    raise error
  end
end

handle_unique_attribute_on_save!(attribute_name, index_name, message) click to toggle source

@param attribute_name [String] @param index_name [String] @param message [Symbol, String] @return [void]

# File lib/has_unique_attribute.rb, line 58
def handle_unique_attribute_on_save!(attribute_name, index_name, message)
  existing_method = instance_method(:save!)

  define_method(:save!) do |*args, **kwargs|
    existing_method.bind(self).call(*args, **kwargs)
  rescue ActiveRecord::RecordNotUnique => error
    if error.message.include?(index_name)
      errors.add(attribute_name, message)

      raise ActiveRecord::RecordInvalid, self
    end

    raise error
  end
end