Module: CollectiveIdea::Acts::NestedSet::Base::ClassMethods

Defined in:
lib/awesome_nested_set/base.rb

Instance Method Summary collapse

Instance Method Details

#after_move(*args, &block) ⇒ Object 



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# File 'lib/awesome_nested_set/base.rb', line 234

def after_move(*args, &block)
  set_callback :move, :after, *args, &block
end

#all_roots_valid? ⇒ Boolean

Wrapper for each_root_valid? that can deal with scope.

Returns:



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# File 'lib/awesome_nested_set/base.rb', line 149

def all_roots_valid?
  if acts_as_nested_set_options[:scope]
    roots(:group => scope_column_names).group_by{|record| scope_column_names.collect{|col| record.send(col.to_sym)}}.all? do |scope, grouped_roots|
      each_root_valid?(grouped_roots)
    end
  else
    each_root_valid?(roots)
  end
end

#before_move(*args, &block) ⇒ Object 



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# File 'lib/awesome_nested_set/base.rb', line 230

def before_move(*args, &block)
  set_callback :move, :before, *args, &block
end

#each_root_valid?(roots_to_validate) ⇒ Boolean

Returns:



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# File 'lib/awesome_nested_set/base.rb', line 159

def each_root_valid?(roots_to_validate)
  left = right = 0
  roots_to_validate.all? do |root|
    (root.left > left && root.right > right).tap do
      left = root.left
      right = root.right
    end
  end
end

#each_with_level(objects) ⇒ 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/base.rb', line 214

def each_with_level(objects)
  path = [nil]
  objects.each do |o|
    if o.parent_id != path.last
      # we are on a new level, did we decent or ascent?
      if path.include?(o.parent_id)
        # remove wrong wrong tailing paths elements
        path.pop while path.last != o.parent_id
      else
        path << o.parent_id
      end
    end
    yield(o, path.length - 1)
  end
end

#left_and_rights_valid? ⇒ Boolean

Returns:



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# File 'lib/awesome_nested_set/base.rb', line 120

def left_and_rights_valid?
  count(
    :joins => "LEFT OUTER JOIN #{quoted_table_name} AS parent ON " +
      "#{quoted_table_name}.#{quoted_parent_column_name} = parent.#{primary_key}",
    :conditions =>
      "#{quoted_table_name}.#{quoted_left_column_name} IS NULL OR " +
      "#{quoted_table_name}.#{quoted_right_column_name} IS NULL OR " +
      "#{quoted_table_name}.#{quoted_left_column_name} >= " +
        "#{quoted_table_name}.#{quoted_right_column_name} OR " +
      "(#{quoted_table_name}.#{quoted_parent_column_name} IS NOT NULL AND " +
        "(#{quoted_table_name}.#{quoted_left_column_name} <= parent.#{quoted_left_column_name} OR " +
        "#{quoted_table_name}.#{quoted_right_column_name} >= parent.#{quoted_right_column_name}))"
  ) == 0
end

#no_duplicates_for_columns? ⇒ Boolean

Returns:



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# File 'lib/awesome_nested_set/base.rb', line 135

def no_duplicates_for_columns?
  scope_string = Array(acts_as_nested_set_options[:scope]).map do |c|
    connection.quote_column_name(c)
  end.push(nil).join(", ")
  [quoted_left_column_name, quoted_right_column_name].all? do |column|
    # No duplicates
    first(
      :select => "#{scope_string}#{column}, COUNT(#{column})",
      :group => "#{scope_string}#{column}
        HAVING COUNT(#{column}) > 1").nil?
  end
end

#rebuild! ⇒ Object

Rebuilds the left & rights if unset or invalid. Also very useful for converting from acts_as_tree.



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# File 'lib/awesome_nested_set/base.rb', line 170

def rebuild!
  # Don't rebuild a valid tree.
  return true if valid?

  scope = lambda{|node|}
  if acts_as_nested_set_options[:scope]
    scope = lambda{|node|
      scope_column_names.inject(""){|str, column_name|
        str << "AND #{connection.quote_column_name(column_name)} = #{connection.quote(node.send(column_name.to_sym))} "
      }
    }
  end
  indices = {}

  set_left_and_rights = lambda do |node|
    # set left
    node[left_column_name] = indices[scope.call(node)] += 1
    # find
    where("#{quoted_parent_column_name} = ? #{scope.call(node)}", node).
      order("#{quoted_left_column_name}, #{quoted_right_column_name}, id").
      all.each{|n| set_left_and_rights.call(n) }
    # set right
    node[right_column_name] = indices[scope.call(node)] += 1
    node.save!
  end

  # Find root node(s)
  root_nodes = where(parent_column_name => nil).
      order("#{quoted_left_column_name}, #{quoted_right_column_name}, id").
      all.each do |root_node|
    # setup index for this scope
    indices[scope.call(root_node)] ||= 0
    set_left_and_rights.call(root_node)
  end
end

#root ⇒ Object

Returns the first root



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# File 'lib/awesome_nested_set/base.rb', line 112

def root
  roots.first
end

#valid? ⇒ Boolean

Returns:



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# File 'lib/awesome_nested_set/base.rb', line 116

def valid?
  left_and_rights_valid? && no_duplicates_for_columns? && all_roots_valid?
end