Define icons for actions

[mvano]

This PR adds an icon attribute to NotificationAction, as proposed in #59

[beverloo]

"may be modified" is a bit ambiguous. What about the following phrasing?

Some platforms may modify an [action item resource] to better match the platform's visual style
before displaying it to the user, for example by adding rounded corners or painting it in a specific
color. It is recommended to use an icon that handles such cases gracefully and does not lose
important information through e.g. loss of color or clipped corners.

It would be great if we could add something among the lines of "TEST!", but it's already quite verbose as-is.

[mvano]

Done on rephrasing it a bit.

[beverloo]

Overall I think this change is good, a few comments. Two more points:

• How does this work with Supporting multiple image definitions for a Notification #28? I'd be OK with updating Notification.icon and NotificationAction.icon together (since we'll need to accept both USVString and an array anyway), but I do think this raises the priority of Supporting multiple image definitions for a Notification #28, especially since you add a note further about platform-specific behaviour.
• Please don't end the PR's description with a period (per Anne's preferences).
• Please add yourself to the acknowledgements.

[mvano]

I think #28 can be addressed after getting action icons in. I agree that this PR helps motivate addressing it.

[mvano]

All done.

[beverloo]

This looks good to me, also based on the additional data Michael provided in #59. Let's see if we can get some functional feedback from Mozilla.

WDYT @annevk?

[annevk]

There should be a comma before "e.g.".

[mvano]

While this and this page explain how this is recommended by some style guides, primarily American ones, it is not usually required. If anything, a comma after is more commonly recommended, and one could even use both one before and after.

Personally, I find commas look unappealing in combination with the periods, and would prefer not to add any.

[annevk]

Yeah, maybe that's okay. @sideshowbarker has been asking me to do it, but thus far whenever I ask it of others they don't like it. Maybe we need a WHATWG style guide.

[annevk]

This seems reasonable to me. Still trying to find some additional folks to review new features, but this is not that big.

[annevk]

I'll let @sideshowbarker have a look and then probably merge this tomorrow if I don't forget. Feel free to ping me. If you could rebase/squash that'd be appreciated. I'll try to add some Merge advice around the same time.

[sideshowbarker]

I don’t feel strongly but among that arguments in favor or using comma after e.g. are:

• it’s never incorrect no matter what style you follow (as opposed to just being seen as unnecessary)
• it’s the style used in other Web standards (which for consistency with one another mostly follow a convention of using American English style)

So I would prefer that either:

• if you want to use e.g., it should be followed with a comma, and we also make a practice of consistently using a comma after e.g. in all our specs

• you avoid the question by instead just writing it out as for example—with a comma after it and before it as needed; for example:

  and does not lose important information through, for example, loss of color

Incidentally when it’s written out as for example I think the purpose of the comma(s) is clear—in that, you wouldn’t write the above as:

and does not lose important information through for example loss of color

[mvano]

Incidentally when it’s written out as for example I think the purpose of the comma(s) is clear

Oh the purpose is clear. But to me, "e.g." just expands to ", for example," with the commas included, as visually it looks similar enough with the periods.

Anyway, I'm not the editor of this spec, so if consensus is to insist on the commas just let me know whether to add one before, after, or both.

[annevk]

Committed as 362780b with gratuitous use of commas.

Thank you!