Pass a block variable to a callback function that has already arguments

Question

This is my callback:

function evaluateServiceResponse(err, response){
  db.answerCollection.insert({id: response["serviceAnswer"]["id"]}); //problem is this line

}

This is my callback-user:

mysoapclient.invokeServiceMethod(jsonRecords,this.evaluateServiceResponse);

Here is the whole code. Inside process I create a block reference to my database:

process(function(){
  ...
  let db=null;
  db = mongoClient.connect(connectionURL); 
  //Do whatever to create jsonRecords
  mysoapclient.invokeServiceMethod(jsonRecords,this.evaluateServiceResponse);
  ...
});

The invokeServiceMethod talks to service then calls the callback passing it the service response.

How do I get the db reference into my callback evaluateServiceResponse?

Thanks.

Answer 1

Use closure :

function evaluateServiceResponse(db){ 
 return function(err, response){
  db.answerCollection.insert({id: response["serviceAnswer"]["id"]}); //problem is this line
}
}

And use like:

 mysoapclient.invokeServiceMethod(jsonRecords,this.evaluateServiceResponse(db));