Fast: Attribute name naming conventions for fast-components

[nicholasrice]

Opening a discussion based on this discussion: https://github.com/microsoft/fast-dna/pull/3015#discussion_r419574806

I'd like to land a convention surrounding HTML attribute naming for @microsoft/fast-components. Two primary patterns:

No delineator

Native HTML generally (with a few exceptions) creates attribute names by combining lower-case words with no delineation between the words. Eg: readonly, contenteditable, formaction, etc.

Pros:

• More native precedent
• etc?

Hyphen-separated

Hyphen separated words in attribute names are legal in HTML, though the use of hyphens is minimal compared to the above. Examples include all of the aria- attributes, arbitrary data- attributes, accept-charset and http-equiv

Pros:

• readability
• spell-checking
• etc?

Note: I've specifically left out camelCase because HTML is not case-sensitive - see https://codepen.io/rice119/pen/bGVadJZ

[eljefe223]

I think as we get to more complex attribute naming (more than 2 or 3 words) hypens really help break up the attribute names. Just wondering if we should retroactively and go back and fix any multiword attribute names.

[scomea]

Hyphens good IMO. And yes, retroactively correct while we are still in a beta phase.

[EisenbergEffect]

I like hyphens for readability as well. Additionally, since custom element names require a hyphen to prevent conflicts with built-ins, perhaps we should also use hyphens for attributes. That feels more consistent even it it's not required.

[chrisdholt]

My $.02 - If we are providing a transparent API to existing HTML attributes or there is an existing html attribute for what we are exposing as an attribute, we should map to the attribute (example: formaction). If there is not anything pre-existing I think we should go for legibility, readability, etc. I would have a strong hesitation to changing existing html attributes to hyphen-delineated if they are not already (example: formaction => form-action).

[nicholasrice]

@chrisdholt agreed.

For the record, I'm also for preferring hyphens.

[CuddleBunny]

+1 for hyphens. In addition to the points above: being inconsistent with native attributes also makes them stand out to the end-user of these elements as something custom that may need additional attention.

[nicholasrice]

I'm going to call that consensus - we can re-open if new perspectives are presented.