devise_mongo_mapper_adapter.rb

# Monkey patching required for compatibility between MongoMapper (v. 0.8.6) and
# the master branch of Devise heading towards 1.2. It seems some methods have been moved 
# around to different modules/classes within Devise since the 1.1 branch

module Devise
  module Orm
    module MongoMapper
      module Hook
        def devise_modules_hook!
          extend Schema
          yield
          return unless Devise.apply_schema
          devise_modules.each { |m| send(m) if respond_to?(m, true) }
        end
      end

      module Schema
        include Devise::Schema

        # Tell how to apply schema methods
        def apply_devise_schema(name, type, options={})
          type = Time if type == DateTime
          key name, type, options
        end
      end

    end
  end
end

Devise::Models::Authenticatable::ClassMethods.class_eval do
  def find_for_authentication(conditions)
    # find(:first, :conditions => conditions)
    first(conditions)
  end

  # Find an initialize a record setting an error if it can't be found.
  def find_or_initialize_with_error_by(attribute, value, error=:invalid) #:nodoc:
    find_or_initialize_with_errors([attribute], { attribute => value }, error)
  end

  def find_or_initialize_with_errors(required_attributes, attributes, error=:invalid)
    attribute = attributes.keys.first
    value = attributes.values.first
    if value.present?
      conditions = { attribute => value }
      record = first(conditions) # find(:first, :conditions => conditions)
    end

    unless record
      record = new
      if value.present?
        record.send(:"#{attribute}=", value)
      else
        error = :blank
      end
      record.errors.add(attribute, error)
    end

    record
  end

  def generate_token(column)
    loop do
      token = Devise.friendly_token
      # break token unless find(:first, :conditions => { column => token })
      break token unless first({ column => token })
    end
  end
  
end


Devise::Models::Rememberable::ClassMethods.class_eval do
  # Recreate the user based on the stored cookie
  def serialize_from_cookie(id, remember_token)
    conditions = { :id => id, :remember_token => remember_token }
    record = first(conditions) # find(:first, :conditions => conditions)
    record if record && !record.remember_expired?
  end
end  

# Changed method to call Klass.first method which returns a record an instance of 
# the class instead of the Klass.find, which in the case of MongoMapper always returns an
# array, even if there is only one match. Also requires sending id as an explicit
# key/value hash
class Warden::SessionSerializer
  def deserialize(keys)
    klass, id = keys
    klass.constantize.first(:id => id)
  end
end

Devise::RegistrationsController.class_eval do
  protected
    def authenticate_scope!
      send(:"authenticate_#{resource_name}!")
      self.resource = resource_class.first(:id => (send(:"current_#{resource_name}").to_key))
    end
end

MongoMapper::Document.append_extensions(Devise::Models)
MongoMapper::Document.append_extensions(Devise::Orm::MongoMapper::Hook)