Module: MongoNestedSet::ClassMethods

Defined in:
lib/mongo_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/mongo_nested_set.rb', line 110

def all_roots_valid?
  if acts_as_nested_set_options[:scope]
    roots.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

#base_class ⇒ Object 



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# File 'lib/mongo_nested_set.rb', line 68

def base_class
  if superclass == Object
    self
  else
    super
  end
end

#each_root_valid?(roots_to_validate) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mongo_nested_set.rb', line 120

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/mongo_nested_set.rb', line 172

def each_with_level(objects)
  path = [nil]
  objects.sort_by(&left_column_name.to_sym).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:

  • (Boolean) 


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# File 'lib/mongo_nested_set.rb', line 89

def left_and_rights_valid?
  find(:all).detect { |node|
    node.send(left_column_name).nil? ||
    node.send(right_column_name).nil? ||
    node.send(left_column_name) >= node.send(right_column_name) ||
    !node.parent.nil? && (
      node.send(left_column_name) <= node.parent.send(left_column_name) ||
      node.send(right_column_name) >= node.parent.send(right_column_name)
    )
  }.nil?
end

#no_duplicates_for_columns? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mongo_nested_set.rb', line 101

def no_duplicates_for_columns?
  find(:all).inject(true) { |memo, node|
    memo && [left_column_name, right_column_name].inject(true) { |v, column|
      v && count(node.scoped(column.to_sym => node.send(column))) == 1
    }
  }
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/mongo_nested_set.rb', line 131

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({}) { |hash, column_name|
        hash[column_name] = node.send(column_name.to_sym)
        hash
      }
    }
  end
  indices = {}
  
  set_left_and_rights = lambda do |node|
    # set left
    node.send(:"#{left_column_name}=", (indices[scope.call(node)] += 1))
    # find
    find(:all, scope.call(node).merge(parent_column_name => node.id)).each{|n| set_left_and_rights.call(n) }
    # set right
    node.send(:"#{right_column_name}=", (indices[scope.call(node)] += 1))
    node.save!    
  end
                      
  # Find root node(s)
  root_nodes = find(:all, { parent_column_name => nil, :order => "#{left_column_name}, #{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/mongo_nested_set.rb', line 77

def root
  find :first, :parent_id => nil
end

#roots ⇒ Object 



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# File 'lib/mongo_nested_set.rb', line 81

def roots
  find :all, :parent_id => nil, :order => "#{left_column_name} ASC"
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mongo_nested_set.rb', line 85

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