diff options
Diffstat (limited to 'activerecord/lib/active_record/acts/nested_set.rb')
| -rw-r--r-- | activerecord/lib/active_record/acts/nested_set.rb | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/activerecord/lib/active_record/acts/nested_set.rb b/activerecord/lib/active_record/acts/nested_set.rb index 37d79d5f0c..c983e1173c 100644 --- a/activerecord/lib/active_record/acts/nested_set.rb +++ b/activerecord/lib/active_record/acts/nested_set.rb @@ -5,12 +5,12 @@ module ActiveRecord base.extend(ClassMethods) end - # This acts provides Nested Set functionality. Nested Set is similiar to Tree, but with + # This +acts_as+ extension provides Nested Set functionality. Nested Set is similiar to Tree, but with # the added feature that you can select the children and all of their descendents with # a single query. A good use case for this is a threaded post system, where you want # to display every reply to a comment without multiple selects. # - # A google search for "Nested Set" should point you in the direction to explain the + # A Google search for "Nested Set" should point you to in the right direction to explain the # database theory. I figured out a bunch of this from # http://threebit.net/tutorials/nestedset/tutorial1.html # @@ -55,9 +55,9 @@ module ActiveRecord # So, to get all children of an entry, you # SELECT * WHERE CHILD.LEFT IS BETWEEN PARENT.LEFT AND PARENT.RIGHT # - # To get the count, it's (LEFT - RIGHT + 1)/2, etc. + # To get the count, it's <tt>(LEFT - RIGHT + 1)/2</tt>, etc. # - # To get the direct parent, it falls back to using the PARENT_ID field. + # To get the direct parent, it falls back to using the +PARENT_ID+ field. # # There are instance methods for all of these. # @@ -65,17 +65,17 @@ module ActiveRecord # keeping data integrity is a pain, and both adding and removing an entry # require a full table write. # - # This sets up a before_destroy trigger to prune the tree correctly if one of its + # This sets up a +before_destroy+ callback to prune the tree correctly if one of its # elements gets deleted. # module ClassMethods # Configuration options are: # - # * +parent_column+ - specifies the column name to use for keeping the position integer (default: parent_id) - # * +left_column+ - column name for left boundry data, default "lft" - # * +right_column+ - column name for right boundry data, default "rgt" - # * +scope+ - restricts what is to be considered a list. Given a symbol, it'll attach "_id" - # (if that hasn't been already) and use that as the foreign key restriction. It's also possible + # * +parent_column+ - specifies the column name to use for keeping the position integer (default: +parent_id+) + # * +left_column+ - column name for left boundry data, default +lft+ + # * +right_column+ - column name for right boundry data, default +rgt+ + # * +scope+ - restricts what is to be considered a list. Given a symbol, it'll attach <tt>_id</tt> + # (if it hasn't already been added) and use that as the foreign key restriction. It's also possible # to give it an entire string that is interpolated if you need a tighter scope than just a foreign key. # Example: <tt>acts_as_list :scope => 'todo_list_id = #{todo_list_id} AND completed = 0'</tt> def acts_as_nested_set(options = {}) @@ -115,19 +115,19 @@ module ActiveRecord end module InstanceMethods - # Returns true is this is a root node. + # Returns +true+ is this is a root node. def root? parent_id = self[parent_column] (parent_id == 0 || parent_id.nil?) && (self[left_col_name] == 1) && (self[right_col_name] > self[left_col_name]) end - # Returns true is this is a child node + # Returns +true+ is this is a child node def child? parent_id = self[parent_column] !(parent_id == 0 || parent_id.nil?) && (self[left_col_name] > 1) && (self[right_col_name] > self[left_col_name]) end - # Returns true if we have no idea what this is + # Returns +true+ if we have no idea what this is def unknown? !root? && !child? end |