selectors4.txt

====== Selectors Level 4 ======
  * [[http://www.w3.org/TR/css3-selectors/|Selectors 3 PR]]
  * [[http://dev.w3.org/csswg/selectors4/|Selectors 4 ED]]
==== Ideas considered in Editor’s Draft (ED) ====
  * [[ideas:current-url-selector|Current URL Selector (with directory levels)]] – '':local-link()''
  * IDREF combinators: ''[[http://lists.w3.org/Archives/Public/www-style/2000Jan/0152.html|/attr/]]'' syntax, [[http://lists.w3.org/Archives/Public/www-style/2005Oct/0173.html|'':friend(attribute, selector)'']] syntax — ''/attr/'' syntax chosen
  * [[http://lists.w3.org/Archives/Public/www-style/2008Mar/0193.html|:rtl and :ltr pseudo-classes]] (based on source ''dir'' attributes) (or maybe '':dir(rtl|ltr)''?) – '':dir()'' chosen
  * ability to [[http://www.w3.org/TR/2000/WD-css3-selectors-20001005/#subject-pseudo|choose subject in the selector]] ([[http://lists.w3.org/Archives/Public/www-style/2000Oct/0182.html|alternative syntax]]) ([[http://lists.w3.org/Archives/Public/www-style/2002May/0018.html|discussion of syntaxes]]) – ''$'' marker
  * ''[[http://lists.w3.org/Archives/Public/www-style/2009Mar/0146.html|:nth-match(<selector>, <an+b>)]]''
  * ''[[http://lists.w3.org/Archives/Public/www-style/2003Apr/0146.html|:matches()]]'' pseudo-class ([[http://lists.w3.org/Archives/Public/www-style/2000Oct/0182.html|alternate]]) – '':matches()''
  * [[http://lists.w3.org/Archives/Public/www-style/2011Jul/0415.html|case sensitivity in substring attribute selectors]] – ''[attr=val i]'' notation
==== Ideas to consider ====
  * [[http://wiki.csswg.org/spec/css4-ui#more-selectors|CSS4-UI more selectors]] (a potentially growing set of User Interface related selectors).
  * pseudo-attribute selectors, e.g. to select cells that are in the second column of a table: ''%%[#column=2]%%'' – this example done with '':nth-column(2)''
  * [[http://lists.w3.org/Archives/Public/www-style/2011Apr/0817.html|numeric attribute selectors]], e.g. ''%%[height>2]%%'', ''%%[count<=5]%%'', ''%%[balance<0]%%'', ''%%[#row>1]%%''
  * ''%%::quote-start%%'' and ''%%::quote-end%%'', to match characters with the Quotation_Mark property that are direct children of the element and that are  immediately inside the start and end (respectively) of the element, ignoring White_Space characters. (This would help a lot with ''<q>'' in HTML5.)
  * ''[[https://developer.mozilla.org/en/CSS/%3a-moz-placeholder|:placeholder]]'' - matches form elements displaying placeholder text. This allows web developers and theme designers to customize the appearance of placeholder text, which is a light grey color by default. This may not work well if you've changed the background color of your form fields to be a similar color, for example, so you can use this pseudo-class to change the placeholder text color.
  * ''[[http://lists.w3.org/Archives/Public/www-style/2008Nov/0466.html|::window]]'' pseudo-element
  * [[http://lists.w3.org/Archives/Public/www-style/2010Jan/0308.html|limited descendant combinator]] ([[http://www.onderhond.com/blog/work/missing-css-combinator|more info]]) – ''foo>bar, foo>:not(bar)>bar, …'' comes hardly close
  * [[http://lists.w3.org/Archives/Public/www-style/2010Aug/0063.html|Better definition of ::first-letter]], see also note in Selectors L3
  * ''::first-words(n)'', ''::first-lines(n)'', ''::nth-line(an+b)'', ''::last-line'' etc.
  * [[http://lists.w3.org/Archives/Public/www-style/2010Oct/0039.html|semantic pseudo-class selectors]] e.g. for headings or "visible" elements (i.e. not <script> or <style>) akin to '':link'' etc.
  * Clarify that first formatted line is not triggered when preceded by a block http://wiki.csswg.org/spec/css2.1#issue-268
  * [[http://lists.w3.org/Archives/Public/www-style/2010Oct/0849.html|UA hint pseudo-element selectors]] ''::typo'', ''::match'' etc.
  * [[http://lists.w3.org/Archives/Public/www-style/2011Apr/0603.html|empty input selector]]
  * [[http://lists.w3.org/Archives/Public/www-style/2007Nov/0108.html|more of the user action pseudo-classes]]

==== Ideas superseded by other features ====
  * relationship selectors, e.g.:
    * to select cells in a column: ''%%col.foo // td%%'' – done with ''td:column(col.foo)''
    * to select labels applying to an input control: ''%%input // label%%'' – done without further knowledge of markup language, i.e. ''$label /for/ input, $label input''
    * to select map elements associated with an image: ''%%img // map%%'' – opposite of ''input''–''label'' situation, ''img /usemap/ map''
    * to select arbitrary associated elements: ''%%x[href#] // y[id#]%%'' – always any ID in target, ''x /href/ y''
  * [[http://lists.w3.org/Archives/Public/www-style/2010Sep/0339.html|only-child-parent]] Most use cases for the parent selector care only about the only child. This doesn't have the same perf implications as a general parent selector. – solved with '':matches()'' and ''$''
  * [[http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2008-October/016544.html|dynamic values selector]] - already handled by ''::value'' pseudo-element in CSS3-UI.