ImageResource - Missing from the compat tables

[aarongustafson]

What information was incorrect, unhelpful, or incomplete?

The ImageResource spec is not currently represented at all. What’s the best way to add it? I’m happy to help if someone can point me in the right direction.

[queengooborg]

I took a look at the spec, and it appears to define only a dictionary, no interfaces. Currently, we are still deciding whether or not to keep dictionary data in BCD -- see #7287 -- so I feel that we'll need to reach a conclusion on that before we can act on this one.

[rachelandrew]

I'm currently documenting the Background Fetch API, and found this issue because an image resource is used in that API https://wicg.github.io/background-fetch/#dictdef-backgroundfetchuioptions within another dictionary.

We tend to end up documenting these things inline, but it raises an interesting thing with regard to representing these in BCD as image-resource is supported (for example) in BackgroundFetchUpdateUIEvent. However another spec may implement it, and it wouldn't be supported there.

I think when this has been discussed before the decision has been the fact these are dictionaries isn't that interesting to a web developer. They care about using BackgroundFetchUpdateUIEvent for example, and not the fact that they are using an ImageResource. If ImageResource changes to add some new items, then we would update the API(s) that use it, along with their compat data.

I would dearly love #7287 to be resolved however and us to have a clear, documented process for dictionaries, as I keep coming across them!

[aarongustafson]

Totally understand that position, Rachel. Right now, the specs I am aware of that are using ImageResource are the Web App Manifest, the App Info supplement to the Manifest, and Background Fetch. I think there was some talk about the Payment Request API using it as well, but I don’t see it in that spec yet. Perhaps @rayankans has some insight there.

[rayankans]

There's also the Content Index API.

[queengooborg]

In #7287, we made the decision not to record dictionaries separately from the interfaces that use them, since their compatibility data hardly differs, and we're working to remove all existing dictionaries (see #6810). As such, we won't be adding the ImageResource dictionary, at least not on its own.

What we can do instead is add subfeatures to the methods and interfaces that use the dictionary, as suggested in this guideline. Are there methods out there that use this dictionary?

[aarongustafson]

The `ImageResource` dictionary is used in the context of the Web App Manifest in `icons`, `shortcut.icons`, and `screenshots` (which is part of Manifest App Info). This dictionary is also used in Notifications and (I think) Payment Request.