Wasm-bindgen: Missing grab_frame event from ImageCapture

[mahadeer]

Describe the Bug

When i'm trying to capture the webcam image via ImageCapture, the grab_frame method is missing and also the take_photo method seems to be a void.

[alexcrichton]

I wonder if this is a case where our WebIDL we're using is out of date? The source for these APIs doesn't list grab_frame and has a different signature of take_photo than what's documented on MDN. Would you be interested in looking to see if there's an updated version of the WebIDL we can use?

[mahadeer]

Yes i would love to. But to be very honest am completely new to the term WebIDL. So where should i start?

[alexcrichton]

@fitzgen where was it again you pulled all the original WebIDL from?

[fitzgen]

https://searchfox.org/mozilla-central/source/dom/webidl

[mahadeer]

Seems like they have the old one too.

[alexcrichton]

@mahadeer13 maybe you could check other browsers? Is this feature implemented in Firefox?

[mahadeer]

@alexcrichton My bad. These are an experimantal features only works in chrome for now.

[alexcrichton]

No worries!

In that case for now I'm going to close this since we're only adding standardized APIs to js-sys/web-sys for now.

Note though that you can always bind the API locally in your crate without the assistance of web-sys, it'd look like:

#[wasm_bindgen]
extern "C" {
    type ImageCapture;
    #[wasm_bindgen(method, js_name = grabFrame)]
    fn grab_frame(this: &ImageCapture);
}

(etc)

[mahadeer]

Yes thanks for the suggestion, but i'm trying to create some benchmark on drivers using WebSys and Native JavaScript. So i prefer the Rusty way, with just two lines of JS Code.

Or maybe from what you say, every web_sys is going to call the native javascript method again?

[Pauan]

@mahadeer13 Yes, the APIs only exist in JS (not wasm), so every time you call a web_sys (or js_sys or wasm_bindgen) API it will make a call into JS.

[mahadeer]

@Pauan Thanks.