MDM Capture Component screen value

[carlos_valentini3]

Good afternoon everyone.
I have the following situation, I am developing a web dynpro screen java.
And this screen (View) have only the buttons: SAVE, CANCEL, etc.
The screen fields are instantiated through a WebDynpro Components MDM.
Runs this way: wdThis.wdGetItemDetailsCompInterface () setConfiguration ("MDM_BUSINESS_PARTNER_WD", "CREATE_001.");

Now I need the following at the time of the save action, validate certain values entered on the screen by the user.
For example, has the screen have a field named group accounts, the value typed in by the user screen should be within a pre-defined list.
So I need to read the entered value.
How do I in onActionSave, validate this screen value?

[carlos_valentini3]

is possible in the execution of my code in the "SAVE" button

place the call of getFieldValue method for a field component MDM

that my web dynpro this running?

Or this method will only return data that is already stored in the repository MDM?