Subsequent callbacks from a Cordova iOS plugin don't fire

Question

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.commandD         


        

Answer 1

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.