hfill
v2.0.0
Published
A speculative polyfill to use the h element in HTML
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jonathantnealReadme
hfill
hfill lets you use the speculative h element in HTML.
The h element would allow web authors to provide contextual headings without
specifying an explicit level.
<body>
<h>This is a top level heading</h>
<p>....</p>
<section>
<h>This is a second-level heading</h>
<p>....</p>
<section>
<h>This is a third-level heading</h>
<p>....</p>
</section>
</section>
<section>
<p>....</p>
<h>This is another second-level heading</h>
<p>....</p>
</section>
</body>Try it right now using CodePen
hfill is a speculative polyfill which emulates a proposed feature of the
web platform. Therefore, it should only be used in real production situations
as x-h and not h, as the later would otherwise risk creating problems for
the development of the Web if it became widely used prior to standardization
and implementation.
Usage
Add hfill to your build tool:
npm install hfill --save-devImport hfill as a resource.
import hfill from 'hfill';observe
The observe method watches contextual heading elements.
hfill.observe(
document.documentElement // where contextual headings will be observed
'x-h' // tag name of contextual headings
);The observe method will assign a role of heading to the contextual
heading, if it does not already have one. It will then assign an aria-level
corresponding to the heading’s outline depth, which is its number of
article, aside, nav, or section ancestors.
Example:
<body>
<x-h role="heading" aria-level="1">This is a top level heading</x-h>
<p>....</p>
<section>
<x-h role="heading" aria-level="2">This is a second-level heading</x-h>
<p>....</p>
<section>
<x-h role="heading" aria-level="3">This is a third-level heading</x-h>
<p>....</p>
</section>
</section>
</body>style
The style method adds styles for contextual heading elements.
hfill.style(
document.head, // where <style> will be appended
'x-h' // tag name of contextual headings
'font-style:italic' // optional styles (otherwise display:block;font-weight:bold)
['2em', '1.5em', '1em'] // optional heading sizes (otherwise 2em,1.5em,1.17em,1em,.83em,.67em)
);Example:
<style id="hfill-style">x-h{display:block;font-weight:bold}/* ... level-based styles */</style>Level-based styles only use elements to maintain minimal CSS specificity.
x-h {
font-size: 2em;
}
article x-h, aside x-h, nav x-h, section x-h {
font-size: 1.5em;
}
article article x-h, article aside x-h, article nav x-h, article section x-h,
aside article x-h, aside aside x-h, aside nav x-h, aside section x-h,
nav article x-h, nav aside x-h, nav nav x-h, nav section x-h,
section article x-h, section aside x-h, section nav x-h, section section x-h {
font-size: 1.17em;
}
/* etc. */hfill is 665 bytes when ES5 transpiled, minified, and gzipped.