datepicker error in appdesigner

I'm receiving the following error for my text area calculation of age from a datepicker:

Error setting property 'ageNEQO' of class 'A_QuestionnairesR3'. Value must be of type matlab.ui.control.TextArea or be convertible to matlab.ui.control.TextArea.

The previous code in a datepicker callback function worked and output the age in the TextArea in the previous version of Matlab.

 % Value changed function: DatePicker_DoB
        function DatePicker_DoBValueChanged(app, event)           
            % calculate age
            app.DatePicker_DoBValueChanged;
            age = app.DatePicker_DoB.Value;
            DisplayFormat = 'yyyy-mm-dd';
            datenow = datestr(now, DisplayFormat);
            ageout = datestr(age - datenow, 'yy');
            app.TextArea_ageNEQO.ValueChangedFcn = {ageout, string};                 
            if app.TextArea_ageNEQO == ""
                uialert(app.UIFigure, {'You need to enter your', 'date of birth to proceed.'}, 'Error', 'Icon', 'Error');
            end

Now, the calculation for age is not working and there is no output except the error message above.

I need to use the datepicker on a tab with its own callback function. How do I call the DatePicker function on that tab?

DoB = date of birth

datenow should give me the date from my laptop.

app.TextArea_ageNEQO is a TextArea to write the result of the calculation for ageout.

Answer 1

[frankenberry]

I was able to get most of the datepicker to work now.

 age = app.DatePicker_DoB.Value;
            DisplayFormat = 'yyyy-mm-dd'; %
            datenow = datestr(now, DisplayFormat); %DisplayFormat
            ageout = datestr(age - datenow, 'yy');
            app.TextArea_ageNEQO.ValueChangedFcn = {ageout, string};         
            app.TextArea_ageNEQO.Value = [ageout];
            if app.TextArea_ageNEQO.Value == ""
                uialert(app.UIFigure, {'You need to enter your', 'date of birth to proceed.'}, 'Error', 'Icon', 'Error');
            end