valueField and displayField in SelectItem

Smart GWT Technical Q&A
1

I have a selectItem with valueField, displayField and optionDataSource definied. Because of lags in connection with server side, I observed that selectItem is shown first with value from valueField and after the fetch on optionDataSource is completed, the value from displayField is used. Sometimes user has to wait a few seconds and is confused.

I found a FormItemValueFormatter object, which I can attach to my selectItem. But the signature of method

String formatValue(Object value,
                   Record record,
                   DynamicForm form,
                   FormItem item)

is in my opinion insufficient.
In this method, first I’ve got a value from valueField and, in second invocation, from displayField, which suits to the workflow described above. The thing is, I am not able to determine the value in formatValue method come from valueField or displayField.

Can You provide any solution?

2

What would you do in your formatter? The display value is still being fetched, so were you planning to just override and display blank?

3

I have to interchangeably determine the value in formatter comes from valueField or displayField.

In case the value comes from valueField (displayField has not loaded yet) I would like to return a “loading…” message. After the fetch on optionDataSource is completed I return value from displayField.

4

You can use getSelectedRecord() != null to determine if the record containing the displayValue is available yet.

5

Ok, this is exactly what I mean. Thank You!