Tags
webcam vindaloo version vegan unix unicef trojan todo thinkpad textmate testing tagging syntax svn sugar subversion stubbing sphinx spam spaces solaris sitemap site sinatra shoulda sheet set security search schema_info SchemaInfo ruby rinari restaurant relationships refresh rdiff-backup ramaze railsconf08 railsconf07 rails protools production power placeboeffect pink floyd PIC perl overheat outbreak osx os x NYHS NYC nginx netbeans nested nanophotonics mysql music MPEG-4 mongrel model migration microvolunteer macbook mac logrotate logic log linux less leopard keynote JAX javascript java jacksonville imunizator highlighting hanna Handbrake haml hacks google geocoding genghistron gem gaming gabrielle's funny functional fun friends food fixes fixed firefox FF3 ferretThe Decider said about 1 year ago permalink Comment? (0)
Tagged: rails nested set
Awesome Nested Set Revealed!
Ok, there’s nothing new with nested sets in rails but I crawled through the Awsome Nested Set Code from CollectiveIdea on GitHub code and made a quick and dirty cheat sheet. Here you go.
Awesome Nested Set Cheat Sheet:
Basic Usage
Create a root node:
my_root = Category.create! :name => ‘root’Put a new thing inside this root node:
my_new_thing = Category.create! :name => ‘Chair’ my_new_thing.move_to_child_of my_rootPut a “new” new thing inside this “new_thing” node:
my_2nd_new_thing = Category.create! :name => ‘Chair’ my_2nd_new_thing.move_to_child_of my_new_thingNow you should have something that resembles this:
+ root |_____ my_new_thing |_____________ my_2nd_new_thingGratuitous picture of my dog Ella.
Accessing the data:
Class methods:
- Category.root – returns the first root node
- Category.roots – returns all root nodes
Instance methods:
- my_cat.root? – true if this is a root node
- my_cat.leaf? – true if this is a leaf node. It has no children.
- my_cat.leaves – returns array of all nodes without children.
- my_cat.child? – true if this is a child node. It has a parent.
- my_cat.root – root for this node.
- my_cat.parent – returns the immediate parent
- my_cat.self_and_ancestors – returns array of all parents and self
- my_cat.ancestors – returns array of all parents. Not including self.
- my_cat.self_and_siblings – returns array of brothers and sisters and self. All at that level.
- my_cat.siblings – returns array of brothers and sisters. Not including self.
- my_cat.level – returns the level of this object in the tree. root = 0
- my_cat.self_and_descendants – returns array of all children and self
- my_cat.descendants – returns array of all children. Not including self.
- my_cat.children – returns array of immediate children. Just those in the next level.
- my_cat.is_descendent_of?(obj) – returns true if self is nested under obj
- my_cat.is_or_is_descendent_of?(obj) – returns true if self is nested under obj or self is obj
- my_cat.is_ancestor_of?(obj) – returns true if nested by any obj
- my_cat.is_or_is_ancestor_of?(obj) – returns true if nested by any obj or self is obj