Read transactions

In order to cache application events, one may start a read transaction. As long as the read transaction is running, application events are stored and optimized in the event cache.

Usually, each update request via an ODABA API function call creates a read transaction, i.e. events will be cached while the operation is running.

Typically, application events are used internally by the ODABA GUI frame work. In order to avoid useless reactions on the screen (e.g. selecting a table each time, when in instance has been filled into the table), application events are cached in several cases. Since changes in the selection state of a property handle are sent to the GUI event manager, applications iterating through a property handle, which is connected to a GUI control should start a read transaction.

When a read transaction terminates, cached events are sent to the application after being optimized in order to inform the application about the final state of the property handle.