module ActiveRecord::DynamicMatchers

Public Instance Methods

respond_to?(method_id, include_private = false) click to toggle source

Calls superclass method

# File lib/active_record/dynamic_matchers.rb, line 3
def respond_to?(method_id, include_private = false)
  if match = DynamicFinderMatch.match(method_id)
    return true if all_attributes_exists?(match.attribute_names)
  elsif match = DynamicScopeMatch.match(method_id)
    return true if all_attributes_exists?(match.attribute_names)
  end

  super
end

Private Instance Methods

aggregate_mapping(reflection) click to toggle source

# File lib/active_record/dynamic_matchers.rb, line 77
def aggregate_mapping(reflection)
  mapping = reflection.options[:mapping] || [reflection.name, reflection.name]
  mapping.first.is_a?(Array) ? mapping : [mapping]
end

all_attributes_exists?(attribute_names) click to toggle source

# File lib/active_record/dynamic_matchers.rb, line 72
def all_attributes_exists?(attribute_names)
  (expand_attribute_names_for_aggregates(attribute_names) -
   column_methods_hash.keys).empty?
end

expand_attribute_names_for_aggregates(attribute_names) click to toggle source

Similar in purpose to expand_hash_conditions_for_aggregates.

# File lib/active_record/dynamic_matchers.rb, line 60
def expand_attribute_names_for_aggregates(attribute_names)
  attribute_names.map { |attribute_name|
    unless (aggregation = reflect_on_aggregation(attribute_name.to_sym)).nil?
      aggregate_mapping(aggregation).map do |field_attr, _|
        field_attr.to_sym
      end
    else
      attribute_name.to_sym
    end
  }.flatten
end

method_missing(method_id, *arguments, &block) click to toggle source

Enables dynamic finders like User.find_by_user_name(user_name) and <tt>User.scoped_by_user_name(user_name). Refer to Dynamic attribute-based finders section at the top of this file for more detailed information.

It's even possible to use all the additional parameters to find. For example, the full interface for find_all_by_amount is actually find_all_by_amount(amount, options).

Each dynamic finder using scoped_by_* is also defined in the class after it is first invoked, so that future attempts to use it do not run through method_missing.

Calls superclass method

# File lib/active_record/dynamic_matchers.rb, line 24
    def method_missing(method_id, *arguments, &block)
      if match = (DynamicFinderMatch.match(method_id) || DynamicScopeMatch.match(method_id))
        attribute_names = match.attribute_names
        super unless all_attributes_exists?(attribute_names)
        if !(match.is_a?(DynamicFinderMatch) && match.instantiator? && arguments.first.is_a?(Hash)) && arguments.size < attribute_names.size
          method_trace = "#{__FILE__}:#{__LINE__}:in `#{method_id}'"
          backtrace = [method_trace] + caller
          raise ArgumentError, "wrong number of arguments (#{arguments.size} for #{attribute_names.size})", backtrace
        end
        if match.respond_to?(:scope?) && match.scope?
          self.class_eval "            def self.#{method_id}(*args)                                    # def self.scoped_by_user_name_and_password(*args)
              attributes = Hash[[:#{attribute_names.join(',:')}].zip(args)] #   attributes = Hash[[:user_name, :password].zip(args)]
                                                                            #
              scoped(:conditions => attributes)                             #   scoped(:conditions => attributes)
            end                                                             # end
", __FILE__, __LINE__ + 1
          send(method_id, *arguments)
        elsif match.finder?
          options = if arguments.length > attribute_names.size
                      arguments.extract_options!
                    else
                      {}
                    end

          relation = options.any? ? scoped(options) : scoped
          relation.send :find_by_attributes, match, attribute_names, *arguments, &block
        elsif match.instantiator?
          scoped.send :find_or_instantiator_by_attributes, match, attribute_names, *arguments, &block
        end
      else
        super
      end
    end