Gavin Kistner wrote:
DOM Level 2 Core and DOM Level 3 Core both say:
"The NodeList interface provides the abstraction of an ordered
collection of nodes, without defining or constraining how this
collection is implemented. NodeList objects in the DOM are live." [1] [2]
" NodeList and NamedNodeMap objects in the DOM are live; that is,
changes to the underlying document structure are reflected in all
relevant NodeList and NamedNodeMap objects. For example, if a DOM user
gets a NodeList object containing the children of an Element, then
subsequently adds more children to that element (or removes children, or
modifies them), those changes are automatically reflected in the
NodeList, without further action on the user's part. Likewise, changes
to a Node in the tree are reflected in all references to that Node in
NodeListand NamedNodeMap objects." [3] [4]
This is considered to be a bug in the DOM Core specs, which will
hopefully be fixed by Web DOM Core, which is a proposal Simon Pieters is
working on.
The end of section 6 in the Selectors API explicitly contradicts or
attempts to override this (citing the latter section in DOM 3):
"The NodeList object returned by the querySelectorAll() method must be
static, not live. ([DOM-LEVEL-3-CORE], section 1.1.1) Subsequent changes
to the structure of the underlying document must not be reflected in the
NodeList object. This means that the object will instead contain a list
of matching Element nodes that were in the document at the time the list
was created." [5]
The reason this was changed was based on implementation feedback
(specifically from WebKit, IIRC) which implemented this using the same
NodeList interface rather than a separate StaticNodeList interface as
was specified at the time, although the NodeList instances returned were
still static lists.
Please let me know whether or not you are satisified with this response.
--
Lachlan Hunt - Opera Software
http://lachy.id.au/
http://www.opera.com/
