Subsequent callbacks from a Cordova iOS plugin don't fire
cordova, cordova-plugins, ios, objective-c, phonegap-plugins
Solution
So, the issue wasn't in threading/queueing.
It turned out that you are allowed to use a `callbackId` only once unless you tell Cordova not to cleanup that `callbackId` by setting `CDVPluginResult.keepCallback` to `true`. Pay attention that `keepCallback` isn't a `BOOL` property, so you may need to call `[pluginResult setKeepCallbackAsBool:YES];`
CDVPluginResult* pluginResult = [sendPluginResult resultWithStatus:CDVCommandStatus_OK messageAsString:key];
[pluginResult setKeepCallbackAsBool:YES]; // here we tell Cordova not to cleanup the callback id after sendPluginResult()
[self.commandDelegate sendPluginResult:pluginResult callbackId:monitoredRegions.callbackId];
What messes things up is that if you introduce a blocking call like `alert()` in that callback, Cordova will let you make multiple successive `sendPluginResult` with the same `callbackId`.
Keep in mind that you may need to `sendPluginResult` with a `CDVPluginResult` which `keepCallback` is `false` to release the `callbackId` that you don't need anymore.
Problem
I have troubles with firing immediately subsequent callbacks from a cordova plugin (an iOS one). In XCode debugger I clearly see it steps over ``` [self.commandDelegate sendPluginResult:pluginResult callbackId:monitoredRegions.callbackId]; ``` several times (in immediate succession), each time with a slightly different `pluginResult`. That gets triggered by ``` [locationManager requestStateForRegion:region]; ``` which I don't (and can't) control. The problem is, on the Javascript side, the callback gets fired only once. What's (actually not so) strange is that if I introduce some blocking in that callback, like `alert()`, the callback gets fired several times (as expected). That's cool but I don't need any `alert()` in the app. If I understand it, the `commandDelegate` should take care of threading and queueing, but it seems like it doesn't. The question is, how to get the JS callback fired each time `sendPluginResult` gets called. Many thanks!