x/y/width/height attributes on HTML elements

[zcorpan]

[[
‘canvas’
‘foreignObject’
‘iframe’
‘image’
‘video’
Let box be the tightest rectangle in coordinate space space that contains the positioning rectangle defined by the ‘x’, ‘y’, ‘width’ and ‘height’ geometric properties of the element.
...
]]
https://svgwg.org/svg2-draft/coords.html#ContainerElementBoudingBoxComputation

The HTML elements here do not have 'x' and 'y' attributes defined in HTML. Do you propose making them conforming for HTML?

How is the value taken from the 'width' and 'height' attributes for HTML elements? It could use the computed value from CSS (or some such), or use https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-dimension-values (can be error, percentage, or a length) if you want just the attribute and ignore any CSS...

Related
#240
whatwg/html#919

[AmeliaBR]

No "geometric properties" are CSS properties, which is why that sentence was recently corrected!

For the SVG-namespaced elements, the geometric properties have equivalent presentation attributes, but for the HTML we are not proposing anything new.

The HTML width and height attributes will be expected to affect the CSS as defaults, same as they do in regular CSS/HTML layout.

I've just recently added a clarifying note to the Embedding chapter: https://svgwg.org/svg2-draft/embedded.html#Placement

I will need to change it to indicate that most of the HTML width/height attributes allow percentages. Canvas is the exception, because the attributes set the actual pixel size of the canvas.

Any other suggested changes?

[zcorpan]

Thanks!

I will need to change it to indicate that most of the HTML width/height attributes allow percentages.

That would only apply to implementors, not authors, since using percentages is non-conforming.

[AmeliaBR]

since using percentages is non-conforming.

Ah, that explains my confusion. I think I'll skirt the issue and not mention them at all; it's only an informative note, with a link to the HTML spec for the details.