On 2011-10-19 16:08, Alex Russell wrote:
On Wed, Oct 19, 2011 at 1:54 PM, Lachlan Hunt<lachlan.h...@lachy.id.au> wrote:
I have attempted to address this problem before and the algorithm for
parsing a *scoped selector string* (basically what you're calling a
rootedSelector) existed in an old draft [1].
That draft also allowed the flexibility of including an explicit :scope
pseudo-class in the selector, which allows for conditional expressions to be
built into the selector itself that can be used to check the state of the
scope element or any of its ancestors.
We could accomodate that by looking at the passed selector and trying
to determine if it includes a ":scope" term. If so, avoid prefixing.
Yes, that's exactly what the draft specified.
That'd allow this sort of flexibility for folks who want to write
things out long-hand or target the scope root in the selector,
possibly returning itself.
I don't see a use case for wanting the proposed method to be able to
return the element itself. The case where it's useful for elements
matching :scope to be the subject of a selector is where you're trying
to filter a list of elements.
e.g.
document.querySelectorAll(".foo:scope", list);
// Returns all elements from list that match.
But this wouldn't make sense
el.find(".foo:scope") // Return itself if it matches.
That result seems effectively like a less efficient boolean check that
is already handled by el.matchesSelector(".foo").
I''d also support a resolution for this sort of power-tool that
forces people to use document.qsa("...",scopeEl) to get at that sort
of thing.
If there was no special handling to check for an explicit :scope, that
would mean that any selector that does include :scope explicitly would
not match anything at all.
e.g. el.findAll(":scope>p");
That would be equivalent to:
document.querySelectorAll(":scope :scope>p", el);
Which won't match anything.
That might keep things simpler from an implementation perspective and
doesn't sacrifice any functionality being requested.
--
Lachlan Hunt - Opera Software
http://lachy.id.au/
http://www.opera.com/
