Package io.objectbox.reactive

Interface DataTransformer<FROM,TO>

Type Parameters:

FROM - Data type this transformer receives

TO - Type of transformed data

public interface DataTransformer<FROM,TO>

Transforms or processes data before it is given to subscribed DataObservers. A transformer is set via SubscriptionBuilder.transform(DataTransformer).

Note that a transformer is not required to actually "transform" any data. Technically, it's fine to return the same data it received and just do some processing with it.

Threading notes: transformations are executed sequentially on a background thread owned by the subscription publisher. It is OK to perform long lasting operations, however this will block notifications to all other observers until finished.

Method Summary

Modifier and Type	Method	Description
TO	transform(FROM source)	Transforms/processes the given data.

Method Details

transform

TO transform(FROM source)
      throws Exception

Transforms/processes the given data.

Parameters:

source - data to be transformed

Returns:

transformed data

Throws:

Exception - Transformers may throw any exceptions, which can be reacted on via SubscriptionBuilder.onError(ErrorObserver).