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Re: Opera's Proposal for :context Selector

From: Andrew Fedoniouk <news@terrainformatica.com>
Date: Sun, 13 Jul 2008 15:47:30 -0700
Message-ID: <487A8602.5010904@terrainformatica.com>
To: Lachlan Hunt <lachlan.hunt@lachy.id.au>
CC: fantasai <fantasai.lists@inkedblade.net>, www-style <www-style@w3.org>

Lachlan Hunt wrote:
> fantasai wrote:
>> Have you considered handling these queries by passing an option to 
>> querySelector that scopes the selector to the context node? (Or in the 
>> case of HTML5 scoped style, defining a syntax for the style element 
>> that does the same.) What are the advantages of doing this with a 
>> pseudo-class instead of that approach?
> I did a full analysis of that and other possible solutions previously on 
> public-webapi.
> http://lists.w3.org/Archives/Public/public-webapi/2008May/0057.html
> http://lists.w3.org/Archives/Public/public-webapi/2008May/0058.html
> The solution discussed in that second email is being considered for 
> Selectors API 2, where a new method would be introduced that performs a 
> pre-parse on the group of selectors, appends :context to the beginning 
> of each selector and then parses as normal.  This will provide implicit 
> scoping and basically standardise the defacto standard of many JS 
> libraries, but the explicit :context gives a little more flexibility. So 
> both would be useful.

Am I correct in my understanding that:


will mean precisely:

   localRoot.querySelector(":context div")


If "yes" then lookup happens *always* from the localRoot element
and that element is exactly the :root in such selectors.

That is why I do not understand why you need special :context pseudo
if we have :root already.

> This is the feature request bug I have for tracking that proposal.
> http://www.w3.org/Bugs/Public/show_bug.cgi?id=5860

Andrew Fedoniouk.

Received on Sunday, 13 July 2008 22:48:12 UTC

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