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

Defined in:
lib/awesome_nested_set.rb

Instance Method Summary collapse

Instance Method Details

#all_roots_valid? ⇒ Boolean

Wrapper for each_root_valid? that can deal with scope.

Returns:

  • (Boolean) 


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# File 'lib/awesome_nested_set.rb', line 141

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

#each_root_valid?(roots_to_validate) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/awesome_nested_set.rb', line 151

def each_root_valid?(roots_to_validate)
  left = right = 0
  roots_to_validate.all? do |root|
    returning(root.left > left && root.right > right) 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.rb', line 202

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 descend or ascend?
      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:

  • (Boolean) 


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

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:

  • (Boolean) 


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# File 'lib/awesome_nested_set.rb', line 127

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
    find(: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.rb', line 162

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
    find(:all, :conditions => ["#{quoted_parent_column_name} = ? #{scope.call(node)}", node], :order => "#{quoted_left_column_name}, #{quoted_right_column_name}, id").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 = find(:all, :conditions => "#{quoted_parent_column_name} IS NULL", :order => "#{quoted_left_column_name}, #{quoted_right_column_name}, id").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.rb', line 104

def root
  roots.first
end

#traverse(flat = false, mover = nil, &block) ⇒ Object

Returns the entire set as a nested array. If flat is true then a flat array is returned instead. Specify mover to exclude any impossible moves. Pass a block to perform an operation on each item. The block arguments are |item, descendants, level|.



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# File 'lib/awesome_nested_set.rb', line 222

def traverse(flat = false, mover = nil, &block)
  descendants = all(:order => quoted_left_column_name)
  array = []

  while not descendants.empty?
    items = descendants.shift.traverse(flat, mover, descendants, 0, &block)
    array.send flat ? 'concat' : '<<', items
  end

  return array
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/awesome_nested_set.rb', line 108

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