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Class WhittakerTech::Midas::Engine

Inherits: Rails::Engine

The Midas Engine provides monetary value management capabilities as a Rails Engine. It integrates seamlessly with Rails applications to add currency handling, coin management, and monetary formatting functionality through the Bankable concern and related components.

This engine follows Rails Engine conventions and can be mounted in any Rails application to provide comprehensive monetary value handling capabilities. It includes models, helpers, and utilities for working with currencies and monetary amounts.

Features

  • Bankable Concern: Allows any Active Record model to have monetary attributes
  • Coin Model: Stores monetary values with currency information
  • Form Helpers: View helpers for monetary input and display
  • Currency Management: Integration with the Money gem for currency operations
  • Namespace Isolation: Clean separation from host application code

Installation and Setup

Add the engine to your Rails application's Gemfile and run bundle install. The engine will automatically configure itself when Rails boots.

Usage in Host Applications

Once installed, the engine's functionality becomes available throughout your Rails application:

Configuration

The engine provides several configuration points:

  • Eager Loading: Automatically configures model loading paths
  • Helper Integration: Injects form helpers into ActionView
  • Namespace Isolation: Keeps engine code separate from host application

Directory Structure

The engine follows standard Rails Engine structure:

  • app/models/: Coin model and concerns
  • app/helpers/: Form helpers for monetary inputs
  • db/migrate/: Database migrations for coin storage
  • lib/: Engine configuration and initialization

Database Integration

The engine provides database migrations that create the necessary tables for storing monetary values. Run migrations after installation:

Namespace Isolation

The engine uses isolate_namespace to prevent conflicts with host application code. All engine components are properly namespaced under WhittakerTech::Midas.

Helper Integration

Form helpers are automatically made available in all views through an initializer that extends ActionView::Base when the view layer loads. This provides seamless integration without requiring manual includes.

Eager Loading

The engine configures additional eager load paths to ensure all models are properly loaded in production environments. This includes the models directory which contains the Coin model and Bankable concern.

Thread Safety

The engine follows Rails conventions for thread safety and can be safely used in multi-threaded environments like Puma or Falcon.

Development and Testing

The engine can be developed and tested independently using its own test suite, or integrated into a host application for testing.

See also:

  • WhittakerTech::Midas::Bankable
  • WhittakerTech::Midas::Coin

  • WhittakerTech::Midas::FormHelper

  • @since 0.1.0

@example Adding to a Rails application 

# In your Gemfile
gem 'whittaker_tech-midas'

# The engine auto-configures on Rails boot
# No additional setup required

@example Using Bankable in models 

class Product < ApplicationRecord
  include WhittakerTech::Midas::Bankable
  has_coin :price
end

@example Using form helpers in views 

<%= form_with model: @product do |form| %>
  <%= form.money_field :price %>
<% end %>

@example Running migrations 

rails db:migrate