[invokers] Share command

[lukewarlow]

Split out from another issue. (#972)

Similar to copy action #952 but for web share API.

The default behaviour could be sharing the current URL. I've been collecting use cases to inform a proposal for button type="share" but button command="share" would achieve the same goal.

[github-actions]

There hasn't been any discussion on this issue for a while, so we're marking it as stale. If you choose to kick off the discussion again, we'll remove the 'stale' label.

[lukewarlow]

Note: One potential issue related to this command might be browser compatability issues with the underlying Web Share API.

Web Share has a few possible options that we could work with.

<!-- Corresponding call: navigator.share({text: "Text to Share"}); -->
<button commandfor="p" command="share">
  Share
</button>
<p id="p">Text to share</p>

<!-- Corresponding call: navigator.share({text: "Other text to Share"}); -->
<button id="self" commandfor="self" command="share" value="Other text to Share">
  Share
</button>

<!-- Corresponding call: navigator.share({url: "https://example.com"}); -->
<button id="self-url" commandfor="self-url" command="share" value="https://example.com">
  Share
</button>

Maybe files too?

<!-- Corresponding call: navigator.share({files: [...]}); -->
<button commandfor="img" command="share">
  Share Image
</button>
<img src="..." alt="...">

[lukewarlow]

Open question around how and when to set title, text, url and files. A common case would be to share the page itself. Maybe we can special case the html element such that it as a target will populate title from the title element, and URL from the current URL?

[lukewarlow]

https://codepen.io/lukewarlow/pen/OPJZJKY - Possibly something like this but more generalised?

[github-actions]

There hasn't been any discussion on this issue for a while, so we're marking it as stale. If you choose to kick off the discussion again, we'll remove the 'stale' label.