Contents

# frozen_string_literal: true

module Upgrow
  # A Schema that dynamically infers attribute names from an Active Record Base,
  # plus the attributes from an original Schema.
  #
  # This object is used to power Models so they can include Active Record
  # attributes from a matching class based on the Model's name.
  class ActiveRecordSchema
    # Set the Schema's initial state.
    #
    # @param base_name [String] the name of the Active Record Base class that
    #   should be used to fetch attribute names.
    # @param default_schema [ModelSchema] the original Model Schema to be used
    #   to fetch and define custom attributes.
    def initialize(base_name, default_schema)
      @base_name = base_name
      @default_schema = default_schema
    end

    # Define a custom attribute in the default Schema.
    #
    # @param name [Symbol] the name of the new attribute.
    def attribute(name)
      @default_schema.attribute(name)
    end

    # Define a custom association in the default Schema.
    #
    # @param name [Symbol] the name of the association.
    def association(name)
      @default_schema.association(name)
    end

    # The list of attribute names. This is an aggregate of both the attributes
    # from the Active Record Base as well as any custom attributes from the
    # default Schema.
    #
    # @return [Array<Symbol>] the list of attribute names.
    def attribute_names
      base.attribute_names.map(&:to_sym) | @default_schema.attribute_names
    end

    # The list of association names. This is an aggregate of both the
    # associations from the Active Record Base as well as any custom
    # associations from the default Schema.
    #
    # @return [Array<Symbol>] the list of attribute names.
    def association_names
      association_names = base.reflections.keys.map(&:to_sym)

      association_names | @default_schema.association_names
    end

    private

    def base
      Object.const_get(@base_name)
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
upgrow-0.0.5	lib/upgrow/active_record_schema.rb