Methods

Included Modules

ActiveRecord::Base

Public Class Methods

has_ancestry(options = {}) click to toggle source
# File lib/ancestry/has_ancestry.rb, line 2
def has_ancestry options = {}
  # Check options
  raise Ancestry::AncestryException.new("Options for has_ancestry must be in a hash.") unless options.is_a? Hash
  options.each do |key, value|
    unless [:ancestry_column, :orphan_strategy, :cache_depth, :depth_cache_column, :primary_key_format].include? key
      raise Ancestry::AncestryException.new("Unknown option for has_ancestry: #{key.inspect} => #{value.inspect}.")
    end
  end
  
  # Include instance methods
  include Ancestry::InstanceMethods

  # Include dynamic class methods
  extend Ancestry::ClassMethods

  # Create ancestry column accessor and set to option or default
  cattr_accessor :ancestry_column
  self.ancestry_column = options[:ancestry_column] || :ancestry

  # Create orphan strategy accessor and set to option or default (writer comes from DynamicClassMethods)
  cattr_reader :orphan_strategy
  self.orphan_strategy = options[:orphan_strategy] || :destroy

  # Save self as base class (for STI)
  cattr_accessor :base_class
  self.base_class = self
  
  # Validate format of ancestry column value
  primary_key_format = options[:primary_key_format] || /[0-9]+/
  validates_format_of ancestry_column, :with => /\A#{primary_key_format.source}(\/#{primary_key_format.source})*\Z/, :allow_nil => true

  # Validate that the ancestor ids don't include own id
  validate :ancestry_exclude_self
  
  # Save ActiveRecord version
  self.cattr_accessor :rails_3
  self.rails_3 = defined?(ActiveRecord::VERSION) && ActiveRecord::VERSION::MAJOR >= 3
  
  # Workaround to support Rails 2
  scope_method = if rails_3 then :scope else :named_scope end

  # Named scopes
  send scope_method, :roots, :conditions => {ancestry_column => nil}
  send scope_method, :ancestors_of, lambda { |object| {:conditions => to_node(object).ancestor_conditions} }
  send scope_method, :children_of, lambda { |object| {:conditions => to_node(object).child_conditions} }
  send scope_method, :descendants_of, lambda { |object| {:conditions => to_node(object).descendant_conditions} }
  send scope_method, :subtree_of, lambda { |object| {:conditions => to_node(object).subtree_conditions} }
  send scope_method, :siblings_of, lambda { |object| {:conditions => to_node(object).sibling_conditions} }
  send scope_method, :ordered_by_ancestry, :order => "(case when #{table_name}.#{ancestry_column} is null then 0 else 1 end), #{table_name}.#{ancestry_column}"
  send scope_method, :ordered_by_ancestry_and, lambda { |order| {:order => "(case when #{table_name}.#{ancestry_column} is null then 0 else 1 end), #{table_name}.#{ancestry_column}, #{order}"} }
  
  # Update descendants with new ancestry before save
  before_save :update_descendants_with_new_ancestry

  # Apply orphan strategy before destroy
  before_destroy :apply_orphan_strategy

  # Create ancestry column accessor and set to option or default
  if options[:cache_depth]
    # Create accessor for column name and set to option or default
    self.cattr_accessor :depth_cache_column
    self.depth_cache_column = options[:depth_cache_column] || :ancestry_depth

    # Cache depth in depth cache column before save
    before_validation :cache_depth

    # Validate depth column
    validates_numericality_of depth_cache_column, :greater_than_or_equal_to => 0, :only_integer => true, :allow_nil => false
  end
  
  # Create named scopes for depth
  {:before_depth => '<', :to_depth => '<=', :at_depth => '=', :from_depth => '>=', :after_depth => '>'}.each do |scope_name, operator|
    send scope_method, scope_name, lambda { |depth|
      raise Ancestry::AncestryException.new("Named scope '#{scope_name}' is only available when depth caching is enabled.") unless options[:cache_depth]
      {:conditions => ["#{depth_cache_column} #{operator} ?", depth]}
    }
  end
end

[Validate]

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