Module: DataMapper::Is::AwesomeSet

Defined in:
lib/dm-is-awesome_set.rb

Overview

Thanks for looking into dm-is-awesome_set. What makes it so awesome? Well, the fact that it actually works. At least I think it does. Give it a whirl, and if you come across any bugs let me know (check the readme file for information). Most of what you will be concerned with is the move method, though there are some other helper methods for selecting nodes. The way you use it in your model is like so:

def ModelName

 include DataMapper::Resource
 # ... set up your properties ...
is :awesome_set, :scope => [:col1, :col2], :child_key => [:parent_id]

end

Note that scope is optional, and :child_key’s default is [:parent_id]

Defined Under Namespace

Modules: ClassMethods, InstanceMethods

Instance Method Summary collapse

Instance Method Details

#is_awesome_set(options = {}) ⇒ Object

Available options for is awesome_set:

:scope => array of keys for scope (default is [])
:child_key => array of keys for setting the parent-child relationship (default is [:parent_id])



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# File 'lib/dm-is-awesome_set.rb', line 28

def is_awesome_set(options={})
  extend  DataMapper::Is::AwesomeSet::ClassMethods
  include DataMapper::Is::AwesomeSet::InstanceMethods
  
  opts = set_options(options)
  [:child_key, :scope].each {|var| raise "#{var} must be an Array" unless opts[var].is_a?(Array)}

  property :parent_id, Integer, :min => 0, :writer => :protected

  property :lft, Integer, :writer => :private, :index => true
  property :rgt, Integer, :writer => :private, :index => true

  class_opts = {:model => self.name, :child_key => opts[:child_key], :order => [:lft.asc] }
  belongs_to :parent,  class_opts
  has n,     :children, class_opts

  before :save do
    move_without_saving(:root) if lft.nil? #You don't want to use new_record? here.  Trust me, you don't.
  end

end