Behavior Attachment

WORK IN PROGRESS

Comparison between the decorator and element behavior attachment.

	Decorator	Element
Use Cases	Add special UI treatment to all vcards in a document Create an extension to provide extra download options for certain types of links	Custom controls (TODO: expand)
Identity	Does not change the identity of the element.	Creates a new type of element.
Lifetime	Transient, added and removed dynamically.	Permanent, originates with the element’s creation and exists through the lifetime.
Shadow Tree	Each decorator must have its own shadow subtree, and the aggregate shadow tree of an element is composed out of these subtrees.	Only one tree, initialized as the element is created.
DOM API	Should avoid adding any extra methods or properties to the DOM element that’s being decorated.	Explicitly interested in exposing methods or properties on the DOM element as its API.