SimpleModel

A collection of convenience methods for building table-less models. SimpleModel implements:

• ActiveModel::Validations
• ActiveModel::Conversion
• ActiveModel::Validations::Callbacks
• ActiveModel::Dirty
• ActiveModel::Naming
• ActiveModel::Callbacks
• ActiveSupport core extensions (see SimpleModel::Base)

Additionally SimpleModel implements basic model actions

Installation

SimpleModel is available through Rubygems and can be installed via:

$ gem install simple_model

Usage

Basic

  require 'simple_model'

    class Item < SimpleModel::Base
      # Model Actions
      save :save_item, :rollback => :undo_save
      
      # Callbacks
      before_validation :add_to_array
      
      # Attributes
      has_booleans :active, :default => true
      has_booleans :paid
      has_times :created_at, :default => :now
      has_attribute :my_array, :default => []
      
      # Validation
      validates_inclusion_of :price, :in => 10..25
      
      def now
        Time.now
      end

      def file_name
       @file_name ||= "receipt-#{self.created_at.to_i}.txt"
      end

      private

      def add_to_array
        my_array << 1
      end

      def save_item
        begin
          File.open(self.file_name, 'w') do |receipt|
            receipt.puts self.created_at
            receipt.puts "price:#{self.price}"
            receipt.puts "paid:#{self.paid}"
          end
        rescue
          return false
        end
        true
      end

      def undo_save
        File.delete(file_name)
      end
    end
    
    item = Item.new
    item.changed?           # => false
    item.created_at         # => 2011-10-23 21:56:07 -0500
    item.created_at         # => 2011-10-23 21:56:08 -0500
    item.active             # => true
    item.paid               # => nil
    item.paid?              # => false
    item.price              # => 10.0
    item.price = '$1,024.00'
    item.price              # => #<BigDecimal:100c989d8,'0.1024E4',9(27)>
    item.changed?           # => true
    item.price_changed?     # => true
    item.changes            # => {"price"=>[#<BigDecimal:7fc61b250da8,'0.1E2',9(27)>, #<BigDecimal:7fc61b1ba600,'0.1024E4',9(27)>]}
    item.my_array           # => []
    item.valid?             # => false
    items.save!             # raises SimpleModel::ValidationError exception
    item.my_array           # => [1]
    item.price = 15 
    item.persisted?         # => false
    item.save               # => true
    item.persisted?         # => true
    item.changed?           # => false
    item.previous_changes   # => {"price"=>[#<BigDecimal:7fc61b1ba600,'0.1024E4',9(27)>, #<BigDecimal:7fc61b1730e8,'0.15E2',9(27)>], "saved"=>[nil, true]} 

Rails Session Modeling

  require 'simple_model'

    class SessionUser < SimpleModel::Base
      has_attributes :permissions, :default => []
      
      # Returns true only if all required permission are set
      def authorized?(*required_permissions)
        (permissions == (required_permissions | permissions))
      end

       #... lots of other handy methods...#
    end

    class ApplicationController < ActionController::Base
      #... omitted for space ...#
      # Initialize, if necessary, and return our session user object
      def session_user
        session[:user] ||= {:permissions => [:foo,:baz]}
        @session_user  ||= SessionUser.new_with_store(session[:user])
      end
      helper_method :session_user

      private

      # redirect if not authorized
      def authorize(*required_permissions)
        redirect_to '/sessions/error' unless session_user.authorized?(*required_permissions)
      end
    end

    class FoosController < ApplicationController
      before_filter do |c| c.send(:authorize,:foo) # Make sure session user has permission
    end

Contributing to simple_model

• Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
• Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
• Fork the project
• Start a feature/bugfix branch
• Commit and push until you are happy with your contribution
• Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Notes

Release 1.2+ no longer creates instance variables, just uses the attributes hash as the data store.

Thanks

Code based on Rails/ActiveRecord and Appoxy/SimpleRecord