Mutils

Mutils is a general-purpose helper gem for Ruby and Rails apps. Serialization is one supported feature today, with room for more reusable utilities over time.

Today, Mutils primarily provides a class-based serialization API for turning Ruby objects into predictable hashes or JSON.

What it provides

  • attribute declarations for model fields
  • computed serializer methods
  • block-based fields with access to params
  • has_many, has_one, and belongs_to relationships
  • conditional inclusion with if: proc
  • selective field loading with includes:
  • optional JSON root keys with name_tag
  • a Rails generator for serializer scaffolding

Quick start 

gem "mutils"

bundle install

class UserSerializer < Mutils::Serialization::BaseSerializer
  attributes :id, :first_name, :last_name
  custom_methods :full_name

  def full_name
    "#{scope.first_name} #{scope.last_name}"
  end
end

UserSerializer.new(user).to_h
# => { id: 1, first_name: "Ada", last_name: "Lovelace", full_name: "Ada Lovelace" }

Core ideas

  • attributes are always included by default
  • attribute is opt-in by default unless always_include: true
  • custom_methods are always included by default
  • custom_method is opt-in by default unless always_include: true
  • relationships are opt-in by default unless always_include: true

That split is intentional: bulk declarations default to “include now”, while single declarations are useful for optional fields.