The Infolog

When developing a new form or a new table that will have display or edit methods we should be thinking about how costly these types of methods are. Adding lots of these methods to a form can cause a large delay in opening and refreshing as these methods are recalculated every time a refresh is triggered on the form, which can occur when the user edits fields, uses menu items, or presses F5. We have a few options to allow caching of these methods, which can ease the number of round trips to the database.

If the method is declared on the table we can use the cacheAddMethod on the datasource to force the values to be cached. Using this method allows the form build engine to do all of the calculations for the methods in one round trip to the server saving time.

To do this we should call the method on the init of the datasource where the method lives. An example of this can be found on the SalesTable form. The SalesTable table has an edit method called editContactPersonName. This is used in the SalesTable form, however as the form has a lot going on the method is cached. The call to this method can be found in the init of the datasource:

We can also add caching to the control itself within it’s properties. There is a property called CacheDataMethod just under the datamethod which allows you to set the caching:

The settings for “Yes” and “No” are self-explanatory, Auto will cache the data method only when the form datasource is read-only.