from internal structuring point of view, it is impossible that an event is sent twice during one server request processing.
So, double-eventing can only be caused by the client sending two events: example the user clicks a button twice (double click) and then two events are processed on server side.
For the BUTTON we have the extra attribute DOUBLECLICKENABLED which you may set to "false". For other functions (e.g. if you use INVOKEEVENT on IMAGE/PANE/...) you have to ensure the avoidance of double processing on application side.
Is it possible that double processing is caused by double clicking?
you are right. In most cases a button was double-clicked and that was the reason for the double events.
We now explicitly set the attribute "doubleclickenabled" to false. With this measure double events do not occure any more. Thanks.
But "doubleclickenabled"="false" should be the default value. Why do we have to explicitly set this value?
Another source for double events are line items in a fixgrid. In our applications we have a single click strategy for line items in a fixgrid. So we set the attribute "singleclickexecute" to "true".
But sometimes our users are impatient and nervous. Then they click on a line item twice. And this double click leeds to two events on the server side.
I think a fixgrid with "singleclickexecute" = "true" should not react on double clicks anymore.