Readme.rdoc

Steps to get Devise Authentication and CanCan Authorization running on Ruby on Rails 2.3.5 with DataMapper and Bundler on Google AppEngine:¶ ↑

• Install Devise version 1.0.6 as a plugin into the Rails vendor directory. Installing as a Gem did not work for me, maybe due to bundler (see this Issue: github.com/carlhuda/bundler/issues/issue/83, which involves patching Rails boot.rb etc.)

• Add warden and cancan to your Gemfile

• Configure Devise to use DataMapper as the orm in config/initializers/devise.rb

• Setup ActionMailer as described in: gist.github.com/312532 in case you want confirmation of new users via email

• Create a User model, which adds ActiveRecord-validations to the model in case the Devise validation-module will be used. If Devise validations will be used, DataMapper autovalidations should be disabled

• If the rememberable module of Devise is used, the DataMapper-ORM (lib/devise/orm/data_mapper.rb) of Devise needs to be patched to use Time instead of DateTime. Otherwise an exception is thrown on setting the remember-cookie because of a missing .gmtime method

• CanCan 1.1.1 runs out of the box, except for nested resources (e.g. comments belonging to posts). Patch controller_resource.rb to use DataMapper-get instead of ActiveRecord-find

controller_resource.rb

# [...]

   def find(id)
    	    self.model_instance ||= base.get(id)
    end

# [...]

data_mapper.rb

module Devise
  module Orm
    module DataMapper

# [...]

      # Tell how to apply schema methods. This automatically maps :limit to
      # :length and :null to :nullable.
      def apply_schema(name, type, options={})
        return unless Devise.apply_schema

# This automatically converts DateTime to Time
        type = Time if type == DateTime

        SCHEMA_OPTIONS.each do |old_key, new_key|
          next unless options.key?(old_key)
          options[new_key] = options.delete(old_key)
        end

        property name, type, options
      end
    end
  end
end

DataMapper::Model.send(:include, Devise::Models)

Gemfile

# Critical default settings:
disable_system_gems
disable_rubygems
bundle_path '.gems/bundler_gems'

# List gems to bundle here:
gem 'rails_dm_datastore'
gem 'rails', "2.3.5"

# Needed for Devise-Plugin
gem 'warden'
# Authorisation
gem 'cancan'
# Confirmation Mail support
gem "actionmailer-javamail", :require_as => "java_mail"

user.rb

class User
  include DataMapper::Resource

  # Turn off DataMapper auto validations. If the validation module of devise is used, this
  # leads otherwise to duplicate error messages.
  def self.property(name, type, options = {})
    super(name, type, options.merge({:auto_validation => false}))
  end

  property :id,     Serial
 
  # ActiveRecord-compatible validations, only needed in case the validation module is used
  def self.validates_presence_of(name, options = {})
    # Localisation of validtions messages, example
    local_name = I18n.t(name, :default => name, :scope => [:activerecord, :attributes, :user], :count => 1)
    validates_present(name, options.merge({:message => local_name+" must not be empty."}))
  end
  
  # Validations without localised messages 
  def self.validates_uniqueness_of(name, options = {})
    validates_is_unique(name, options)
  end
  def self.validates_format_of(name, options = {})
    validates_format(name, options)
  end
  def self.validates_confirmation_of(name, options = {})
     validates_is_confirmed(name, options)
  end
  def self.validates_length_of(name, options = {})
    validates_length(name, options)
  end

  devise :database_authenticatable, :registerable, :recoverable, :rememberable, :trackable, :validatable, :confirmable
  
  timestamps :at

end

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