Module: CollectiveIdea::Acts::NestedSet::Model::ClassMethods

Defined in:
lib/awesome_nested_set/model.rb

Instance Method Summary collapse

Instance Method Details

#add_to_inverse_association(association, record) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 42

def add_to_inverse_association(association, record)
  inverse_reflection = association.send(:inverse_reflection_for, record)
  inverse = record.association(inverse_reflection.name)
  inverse.target << association.owner
  inverse.loaded!
end

#associate_parents(objects) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 27

def associate_parents(objects)
  return objects unless objects.all? {|o| o.respond_to?(:association)}

  id_indexed = objects.index_by(&primary_column_name.to_sym)
  objects.each do |object|
    association = object.association(:parent)
    parent = id_indexed[object.parent_id]

    if !association.loaded? && parent
      association.target = parent
      add_to_inverse_association(association, parent)
    end
  end
end

#children_of(parent_id) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 49

def children_of(parent_id)
  where arel_table[parent_column_name].eq(parent_id)
end

#each_with_level(objects, &block) ⇒ Object

Iterates over tree elements and determines the current level in the tree. Only accepts default ordering, odering by an other column than lft does not work. This method is much more efficent than calling level because it doesn’t require any additional database queries.

Example:

Category.each_with_level(Category.root.self_and_descendants) do |o, level|



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# File 'lib/awesome_nested_set/model.rb', line 61

def each_with_level(objects, &block)
  Iterator.new(objects).each_with_level(&block)
end

#leaves ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 65

def leaves
  nested_set_scope.where "#{quoted_right_column_full_name} - #{quoted_left_column_full_name} = 1"
end

#left_of(node) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 69

def left_of(node)
  where arel_table[left_column_name].lt(node)
end

#left_of_right_side(node) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 73

def left_of_right_side(node)
  where arel_table[right_column_name].lteq(node)
end

#nested_set_scope(options = {}) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 81

def nested_set_scope(options = {})
  options = {:order => quoted_order_column_full_name}.merge(options)

  where(options[:conditions]).order(options.delete(:order))
end

#primary_key_scope(id) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 87

def primary_key_scope(id)
  where arel_table[primary_column_name].eq(id)
end

#right_of(node) ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 77

def right_of(node)
  where arel_table[left_column_name].gteq(node)
end

#root ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 91

def root
  roots.first
end

#roots ⇒ Object 



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# File 'lib/awesome_nested_set/model.rb', line 95

def roots
  nested_set_scope.children_of nil
end