Async Clipboard API is "all red"

[captainbrosset]

Reported by @tomayac here: https://toot.cafe/@tomayac/112614061442371457

See the status: https://web-platform-dx.github.io/web-features-explorer/features/async-clipboard/

Compare to Can I Use: https://caniuse.com/async-clipboard

Here are the BCD keys used to compute our status:

• api.Clipboard
• api.Clipboard.read
• api.Clipboard.readText
• api.Clipboard.write
• api.Clipboard.writeText
• api.ClipboardEvent
• api.ClipboardEvent.ClipboardEvent
• api.ClipboardEvent.clipboardData
• api.ClipboardItem
• api.ClipboardItem.ClipboardItem
• api.ClipboardItem.getType
• api.ClipboardItem.presentationStyle
• api.ClipboardItem.types
• api.Navigator.clipboard
• api.Permissions.permission_clipboard-read

[ddbeck]

The overall non-support is due to BCD reporting that:

• Firefox and Safari don't support the clipboard-read permission (api.Permissions.permission_clipboard-read).
• Chrome does not support ClipboardItem's presentationStyle property and only partially supports read and readText methods (api.Clipboard.read*).

It's unclear to me whether BCD, caniuse, or both have errors. BCD and caniuse differ significantly. Major differences are:

• readText: BCD says this is partially supported in Chrome, caniuse says Firefox doesn't support it.
• writeText: BCD says this is fully supported in Safari for iOS, but caniuse says it's unsupported.

Resolving this would be a three step process:

• Test and (if applicable) correct the data in BCD.

  The following issues are open on BCD for clipboard data:

  • api.Clipboard.writeText - doesnot work in safari browser mdn/browser-compat-data#22096
  • ClipboardEvent.clipboardData's value is a DataTransfer, but DataTransfer.files isn't cross browser mdn/browser-compat-data#18140
  • api.Clipboard.{read,write} - Split MIME types into subfeatures? mdn/browser-compat-data#7991

  I'd expect that resolving them would go a long way toward resolving this issue in general.

• If this feature is still truly partially supported in any of the core browsers, then this is a web-features bug and it's blocked by Partial support and notes #915. When that's done, mark this as partially supported and explain why. If there are no partials, you can skip this step.

• Check if there are any remaining discrepancies with caniuse. If so, file an issue (or PR) against to caniuse to resolve those differences.

[foolip]

#1315 should improve this.

[foolip]

Some cleanup of the tags BCD keys in mdn/browser-compat-data#23658.

[ddbeck]

Copying from myself on #1294 (comment)

Hmm, yeah, that's iffy data. Two thoughts here:

• The partial seems to be the requirement to have the (non-standard?) clipboard-read permission. I can't find that permission specified anywhere, which makes it hard to understand.

• Those media types should be subfeatures of read instead of notes. Probably something like text/plain and image/png ought to be in compute_from list?

[foolip]

What should we consider the scope of this feature to be?

#1315 would make it navigator.clipboard.writeText(). At the same time https://caniuse.com/async-clipboard is about both reading and writing, as it treats Safari iOS as a partial implementation with the note "Supports writing to clipboard but not reading."

[foolip]

I looked into the Safari iOS issue on caniuse and filed Fyrd/caniuse#7105.

At this point I'm fairly certain that all four methods (read(), readText(), write(), writeText()) work in all browsers, but there are differences in permissions, requirements for user interaction, and UX, that developers need to understand in order to write code that works everywhere. We don't have notes in web-features, so BCD is the place for that.

In web-features, since the scope of the feature is all four methods, I think we should set a Baseline low date accordingly. This will have to be done manually because BCD has partial_implementation still.

[foolip]

I've sent mdn/browser-compat-data#23735 which removes partial impl for Chromium in BCD.