How to convert JSON payload with reserved keyword as name to record in Ballerina - type-conversion

Question

I'm working on a Ballerina service that receives an event and converts the JSON payload to a record using the convert function. The event contains a field with the name type which is a reserved keyword in Ballerina. I can't change the payload of the event. Following is a simplified example code that doesn't compile, because of the string type; in the Event record. Changing type to Type or eventType allows compilation, but the execution throws errors because the field names of the JSON payload don't match the field names of the record.
import ballerina/http;
import ballerina/io;
type Event record {
string id;
string type;
string time;
};
#http:ServiceConfig { basePath: "/" }
service eventservice on new http:Listener(8080) {
#http:ResourceConfig { methods: ["POST"], path: "/" }
resource function handleEvent(http:Caller caller, http:Request request) {
json|error payload = request.getJsonPayload();
Event|error event = Event.convert(payload);
io:println(event);
http:Response response = new;
_ = caller -> respond(response);
}
}
Here is a curl command that sends an example event with a JSON payload and a field with the name type.
curl -X POST localhost:8080 -H "content-type: application/json" -d "{\"id\":\"1\",\"type\":\"newItem\",\"time\":\"now\"}"
I read through Ballerinas API documentation and found nothing on this topic.
Coming from the Java world, I would expect something like an annotation on the records field like this:
type Event record {
string id;
#JsonProperty("type")
string eventType;
string time;
};
Has anyone run into this problem and even better found a solution?

Answer 1

You can define the Event as follows:
type Event record {
string id;
string 'type;
string time;
};
The ' is used to escape the keyword in Ballerina.
When accessing it also you can use it as event.'type
Here you can find an example usage.