Flex :: Data Binding Re-bind When Data Model Not Change, Possible?

If user change the value of the TextInput, then click refresh button to retrieve the data model from backend again, the GUI value will not change back. Re-binding not happen, Since the value of data model not changed, no propertyChanged event fired.In this case, I must Programmatically set the model value to the GUI after data refreshing done.I know bi-directional binding can solve this problem(when user change value on GUI, set the new value to data model immediately). But sometimes I cannot use bi-directional binding, for example, the data model is a int, but user input a non-int value, I cannot set the value to data model. So the value in data model do not change, when refresh data, rebinding still not happen.

This will make the data binding useless. How to resolve this?I put pseudo-code here for now, I will put real code later:1. retrieve a data model from server, via blazeds or something else.2. bind the model to a TextInput on GUI.3. user change the TextInput text.4. User click a refresh button, triger retrieve the model value again.5. Now since the model value do not change, no PropertyChanged event fired.6. GUI value still is the user's input, not the value from the model. can clear the model value before set the velue back, make re-binding happen.(but sometimes you do not know how to clean the model value, take int for example, you may do not know the original value and happen set the same value). Or I can manually set the model value to GUI. But both are not good looking.