Browser compatibility data on OPFS page

[josephrocca]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/API/File_System_API/Origin_private_file_system

What specific section or headline is this issue about?

Browser compatibility

What information was incorrect, unhelpful, or incomplete?

At the top of the page there's some text "supporting browsers" which link to this URL: https://developer.mozilla.org/en-US/docs/Web/API/File_System_API/Origin_private_file_system#browser_compatibility

But there's no browser compat section on that page, so nothing happens when you click it.

What did you expect to see?

Browser compat data

Do you have any supporting links, references, or citations?

No response

Do you have anything more you want to share?

Thanks!

MDN metadata

Page report details

• Folder: en-us/web/api/file_system_api/origin_private_file_system
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/API/File_System_API/Origin_private_file_system
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/api/file_system_api/origin_private_file_system/index.md
• Last commit: f216422
• Document last modified: 2024-10-16T05:12:45.000Z

[Josh-Cena]

Duplicate of mdn/yari#11290

[josephrocca]

Hey @Josh-Cena, this was originally about the broken link, because I though the compat data was on compiled in one spot on the File System Access API page, but then I realized that it's nowhere to be found, so I updated the issue to be about the compat data itself.

I notice that there are other issues here about lack of compat data which are open, so I assume this one should stay open?

I unfortunately don't have comprehensive info, but after some research just now, this is what I determined:

• Supported in Firefox since v111: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/111
• Supported in Safari since macOS 12.2 and iOS 15.2:
  • https://webkit.org/blog/12257/the-file-system-access-api-with-origin-private-file-system/
  • https://developer.apple.com/documentation/safari-release-notes/safari-15_2-release-notes
• Chrome Desktop since v102 and Chrome Android since v109: https://developer.chrome.com/blog/new-in-chrome-109

Notable quote from a popular database: https://rxdb.info/rx-storage-opfs.html

From the beginning of 2023, the Origin Private File System API is supported by all modern browsers like Safari, Chrome, Edge and Firefox. Only Internet Explorer is not supported and likely will never get support.

[Josh-Cena]

Support is tied to particular methods and interfaces, not to an API as a whole. For example, you will want to find support data on https://developer.mozilla.org/en-US/docs/Web/API/StorageManager/getDirectory.

[josephrocca]

@Josh-Cena AFAIK the above versions I gave are for nagivator.storage.getDirectory, since that's all you need for OPFS support. IIUC, everything else is specified "upstream" since it's used for regular File System Access API stuff.

[josephrocca]

Ah, all the versions are available on the FileSystemSyncAccessHandle page from the first row of the compat table, since this is only available in OPFS.

Looks like they align with the versions I specified above - except that not sure what Safari version macOS 12.2 corresponds to, or if that was a typo in their release notes. It definitely wasn't available in Safari 12.2 on macOS. I think I trust the FileSystemSyncAccessHandle data - i.e. Safari 15.2 on both iOS and macOS.

So in summary: It seems like it'd make sense to add a single row on the Origin Private File System page with nagivator.storage.getDirectory, which uses the FileSystemSyncAccessHandle versions.

[Josh-Cena]

Our convention is to not include compatibility information in API landing pages, hence the issue I linked which will remove the reference to the browser compat section if it doesn't exist.

[josephrocca]

Is this convention strict? I noticed that this API landing page does have xr compatibility data:

https://developer.mozilla.org/en-US/docs/Web/API/WebXR_Device_API

Which is copied from here:

https://developer.mozilla.org/en-US/docs/Web/API/Navigator/xr

I'm wondering how people are supposed to work out whether a browser supports OPFS. If analogy to WebXR example isn't possible, would it e.g. be possible to add a "Browser support" section at the bottom of the page which has a sentence or two that directs people to https://developer.mozilla.org/en-US/docs/Web/API/StorageManager/getDirectory ? Or some other way to help people find it?

[Josh-Cena]

It's not strict, but we have far more cases where we do hold it than where we don't. Some APIs, like WebXR, has a single entrypoint (navigator.xr), so its support story can be told entirely through that interface, so we are more open to including it; other places that have multiple entrypoints and extensions will become very messy. Consider the extreme case: what do you mean when you say "supports the DOM API"? The norm we have established is that API landing pages are just for tutorial purposes: they build an overview of what's available and how you use them. The compat data is considered a technical detail that's tied to each individual feature, not to the API surface as a whole, so we don't put it in the landing page. In the worst case, you would need to look up each individual API you are using, since each one of those methods/interfaces may have a different support status.

[josephrocca]

WebXR, has a single entrypoint

That makes sense, but that's exactly the case we have here, right? I.e. 'OPFS' as a feature is really just nagivator.storage.getDirectory - and from there onwards it's basically just normal File System Access stuff.

I assume this is why, for example, web.dev links to the nagivator.storage.getDirectory page if you click "Source" their support data:

https://web.dev/articles/origin-private-file-system

[Josh-Cena]

That sounds reasonable—let's see what others say.