Discussing CB-5806 [Windows8] Add keepCallback support to proxy

["Sergey Grebnov (Akvelon)" <v-...@microsoft.com>]

Hi,
I've just found out that due to current windows8 proxy implementation[1] plugins can't specify keepCalback parameter since result of proxy function is always treated as resultant message only. On other platforms we have options to also specify callbackId, custom callbackStatus and keepCallback parameters.

I believe correct implementation way is treating callback result as plugin result object which should include callbackId, status, keepCallback, message, etc ...but we can't change this behavior right now since it will break all already implemented plugins. So I propose the following two solutions:

1. add keepCallback as second optional parameter

            onSuccess = function (result, keepCallback) {
                cordova.callbackSuccess(callbackId,
                        {
                        status: cordova.callbackStatus.OK,
                        message: result,
                        keepCallback: keepCallback == true
                    });

  Usage:  onSuccess(res, true);  onSuccess(undefined, true);

 2. allow plugins to specify keepCallback as part of result
 
  onSuccess = function (result) {
                cordova.callbackSuccess(callbackId,
                        {
                        status: cordova.callbackStatus.OK,
                        message: result,
                        keepCallback: result && result.keepCallback == true
                    });

I personally prefer #1, Thoughts?

[1] https://github.com/apache/cordova-js/blob/master/src/windows8/exec.js#L57

PS. There is aame problem with callbackId

Thx!
Sergey