Skip to content

[selectors4] :where() has 0 specificity #3241

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 23, 2018
Merged

[selectors4] :where() has 0 specificity #3241

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 8 additions & 10 deletions selectors-4/Overview.bs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -139,7 +139,7 @@ Selectors Overview</h2>
<td>[[#matches]]
<td>4
<tr>
<td><code>E:something(<var>s1</var>, <var>s2</var>, &hellip;)</code>
<td><code>E:where(<var>s1</var>, <var>s2</var>, &hellip;)</code>
<td>an E element that matches <a>compound selector</a> <var>s1</var>
and/or <a>compound selector</a> <var>s2</var> but contributes no specificity.
<td>[[#zero-matches]]
Expand Down Expand Up @@ -1199,20 +1199,18 @@ The Negation Pseudo-class: '':not()''</h3>


<h3 id="zero-matches">
The Specificity-adjustment Pseudo-class: '':something()''</h3>
The Specificity-adjustment Pseudo-class: '':where()''</h3>

The Specificity-adjustment pseudo-class, <dfn id="something-pseudo">:something()</dfn>,
The Specificity-adjustment pseudo-class, <dfn id="where-pseudo">:where()</dfn>,
is a functional pseudo-class
with the same syntax and functionality as '':matches()''.
Unlike '':matches()'', neither the '':something'' pseudo-class, nor any of its arguments
Unlike '':matches()'', neither the '':where'' pseudo-class, nor any of its arguments
contribute to the specificity of the selector--
its specificity is always zero.

This is useful for introducing filters in a selector
while keeping the associated style declarations easy to override.

ISSUE: This pseudo-class needs a name. See <a href="https://github.com/w3c/csswg-drafts/issues/1170">previous discussion</a>, <a href="https://github.com/w3c/csswg-drafts/issues/2143">open issue</a>.

<div class="example">
Below is a common example where the specificity heuristic fails
to match author expectations:
Expand All @@ -1228,10 +1226,10 @@ The Specificity-adjustment Pseudo-class: '':something()''</h3>
}
</pre>

However, by using '':something()'' the author can explicitly declare their intent:
However, by using '':where()'' the author can explicitly declare their intent:

<pre>
a:something(:not(:hover)) {
a:where(:not(:hover)) {
text-decoration: none;
}

Expand Down Expand Up @@ -3332,7 +3330,7 @@ Calculating a selector's specificity</h2>
The specificity of a '':not()'' pseudo-class is replaced by
the specificity of the most specific complex selector in its selector list argument.
<li>
The specificity of a '':something()'' pseudo-class is replaced by zero.
The specificity of a '':where()'' pseudo-class is replaced by zero.
</ul>

<div class="example">
Expand All @@ -3343,7 +3341,7 @@ Calculating a selector's specificity</h2>
a specificity of (0,0,1)--like a tag selector--when matched against <code>&lt;em></code>,
and a specificity of (1,0,0)--like an ID selector--when matched against <code>&lt;em id=foo></code>.
<li>
''div:something(em, #foo#bar#baz)'' has
''div:where(em, #foo#bar#baz)'' has
a specificity of (0,0,1): only the ''div'' contributes to selector specificity.
<li>
'':nth-child(even of li, .item)'' has
Expand Down