plugin needs to support callback, but how to set that up

[sdetweil]

I am making a plugin to use in my app.. the raw api looks like

handle=initScanning(xyz)
handle.onData( data){}
handle.onError(data){}
handle.startScanning()

then events flow thru the two on..... handlers

start and end are easy, pass back the handle and use it in a stop(handle) function

and one could use parms to pass a JS onData and OnError function to the init()

I just don't see ANY example of CALLING the funtion

in the .m

    @objc func initScanning(_ call: CAPluginCall){
        const parm1=call.getObject("parm1")?? ''
        const parm2=call.getObject("parm2") ?? ''
        const OnData_callback=call.getObject("onData") ?? nil
        const OnError_callback=call.getObject("onError") ?? nil
        //returns object
            // need a unique id to use on call
        
        try {
            const Handle=rawInit(parm1, parm2)
            if(Handle){
                call.keepAlive = true
                saveCall(ID:????)
                Handle.onData = { context in
                    const lastcall=savedCall(withID: String)
                         //return a common result with a label for the app
                            lastcall.resolve({onData:context})

 or                   --- somehow call thru OnData_callback(context))
                    lastcall.resolve()
                }
                Handle.onError = { context in
                    const lastcall=savedCall(withID: String)
                         //return a common result with a label for the app
                            lastcall.resolve({onEnter:context})

or                    --- somehow call thru OnError_callback(context))
                    lastcall.resolve()
                }
                call.resolve(Handle)  // send back to calling app
            } else {
                call.reject("init failed")
            }
        } catch(error){
            call.reject(error)
        }
    }

i've seen some plugins use NotifyListeners, but no mention of how the listeners got created. I don't do 'AddListener' in any of my apps with current (v3?) plugins. I mostly get an observable to get events on. in my case the raw api will cause a stream of events at Handle.onData(...) that I want to pass back to the app.

one other nagging question..

the .m shows the (function_name, plugincalltype)

how does function_name get mapped to the app function name? as the function_name in the .m is not a literal. or is it converted to a literal as part of the CAPLUGIN wrapper work.. but this side effect is not mentioned anywhere that I have seen.

got most o the plugin working, except for this last part of the callbacks/event handler interface