What is the Type Ahead mechanism?

The goal of the Type Ahead mechanism is to not block the end user if the network connection is slow.

Genero, and therefore Genero Web Client, is based on a field-by-field validation and a runtime-driven field flow. Each time the user leaves a field, the content of the field is sent to the runtime, with a "next field" request. Only the runtime knows if you have AFTER FIELD trigger that can do a conditional NEXT FIELD fieldname. This makes the field flow unpredictable.

Before the introduction of the Type Ahead mechanism, the Genero Web Client handled this issue simply: as only the runtime knows the real field order, the Genero Web Client blocked the User Interface when a field was left, and waited for the answer and the new focus indication. Unfortunately, this behavior was frustrating for users on a slow network. The end user experience can be difficult if the end user has to wait 500 ms each time, and all keys that have been typed are simply dropped.

The HTML5 theme provide the Type Ahead mechanism to enhance the end user experience. The Type Ahead mechanism was also available in the Siverlight theme, starting with version 2.40.