Two-way deno bindings

[eliassjogreen]

• Calling functions in the webview from deno
• Calling deno from webview

To call deno externals from the webview an invoke handler function will be needed. I tried to implement it in src/lib.rs:111 but to no avail. We will also need to implement a way of calling deno callbacks from rust. To do this we will most likely use a polling solution like signal or fs events.

_{Help from some rust wizard would be pretty nice :)}

[treeandgrass]

how about deno and webview share v8 isolate.

electron impleaments:

https://github.com/electron/electron/blob/06bf0d08dc3c941ccce0dfb0f9e0e146d9232605/shell/common/node_bindings.cc

[eliassjogreen]

Probably isn't possible as the isolate isn't shared with plugins (docs.rs).

[jcc10]

Could I ask what is the situation where web-sockets would not be sufficient? Since the web-view front-end (IMO) should be on a different thread then the deno back-end.

[eliassjogreen]

Ideally we want to use the webview_bind function but due to threading issues blocking the deno thread (because the op_webview_run is blocking) we cannot communicate between rust and deno and therefor not have the callbacks needed for implementing binding deno functions to a webview. Web-sockets would not work unless you run the webview in a separate web-worker, and running the webview in a separate web-worker blocks the web-worker deno message polling which means you cannot interact with the webview methods like webview.exit. For further reading on the threading issue.

[eliassjogreen]

I solved it in release 0.5.3, it's far from perfect with a pretty bad js/ts interface but that can always be improved upon. There is an example in examples/external.

[eliassjogreen]

And with the release of 0.5.4 the js/ts interface is pretty good:

for await (const event of webview.iter()) {
  console.log(event)
}