module DataMapper
module Associations
module ManyToOne
OPTIONS = [ :class_name, :child_key, :parent_key, :min, :max ]
private
def many_to_one(name, options = {})
raise ArgumentError, "+name+ should be a Symbol, but was #{name.class}", caller unless Symbol === name
raise ArgumentError, "+options+ should be a Hash, but was #{options.class}", caller unless Hash === options
if (unknown_options = options.keys - OPTIONS).any?
raise ArgumentError, "+options+ contained unknown keys: #{unknown_options * ', '}"
end
child_model_name = DataMapper::Inflection.demodulize(self.name)
parent_model_name = options[:class_name] || DataMapper::Inflection.classify(name)
relationship = relationships(repository.name)[name] = Relationship.new(
name,
repository.name,
child_model_name,
parent_model_name,
options
)
class_eval <<-EOS, __FILE__, __LINE__
def #{name}
#{name}_association
end
def #{name}=(parent_resource)
#{name}_association.replace(parent_resource)
end
private
def #{name}_association
@#{name}_association ||= begin
relationship = self.class.relationships(repository.name)[:#{name}]
association = Proxy.new(relationship, self)
child_associations << association
association
end
end
EOS
relationship
end
class Proxy
instance_methods.each { |m| undef_method m unless %w[ __id__ __send__ class kind_of? should should_not ].include?(m) }
def replace(parent_resource)
@parent_resource = parent_resource
@relationship.attach_parent(@child_resource, @parent_resource) if @parent_resource.nil? || !@parent_resource.new_record?
end
def save
if parent.new_record?
repository(@relationship.repository_name) do
parent.save
@relationship.attach_parent(@child_resource, parent)
end
end
end
private
def initialize(relationship, child_resource)
# raise ArgumentError, "+relationship+ should be a DataMapper::Association::Relationship, but was #{relationship.class}", caller unless Relationship === relationship
# raise ArgumentError, "+child_resource+ should be a DataMapper::Resource, but was #{child_resource.class}", caller unless Resource === child_resource
@relationship = relationship
@child_resource = child_resource
end
def parent
@parent_resource ||= @relationship.get_parent(@child_resource)
end
def method_missing(method, *args, &block)
parent.__send__(method, *args, &block)
end
end # class Proxy
end # module ManyToOne
end # module Associations
end # module DataMapper
