Properly Making Radio buttons Mandatory on Suitelets

Create a Suitelet like the one below:

function mySuitelet(request, response)
{
        if(request.getMethod() == 'GET')
        {
                var form = nlapiCreateForm('my form');
                
                form.addField('custpage_radio', 'radio', 'Alpha', 'a');
                form.addField('custpage_radio', 'radio','Beta','b');
                form.addField('custpage_radio', 'radio','Charlie','c');
                form.addField('custpage_radio', 'radio', 'Delta', 'd'); 
                form.getField('custpage_radio', 'a').setMandatory(true);
                
                var machine = form.addSubList('custpage_mysublist', 'inlineeditor', 'my sublist');
                
                var selectField = machine.addField('myselectfield', 'select', 'My Select Field');
                selectField.addSelectOption('1', 'One');
                selectField.addSelectOption('2', 'Two');
                selectField.addSelectOption('3', 'Three');
                
                form.addSubmitButton('submit');
                response.writePage(form);
        }
        else
        {
                
        }
}

 

After that, run/launch the Suitelet. Without making any selection, click Submit. The form would be submitted and no error would be triggered. In order to make the radio button field mandatory, use setDefaultValue instead. See sample below:

function mySuitelet(request, response)
{
        if(request.getMethod() == 'GET')
        {
                var form = nlapiCreateForm('my form');
                
                form.addField('custpage_alphbets', 'radio', 'Alpha', 'a');
                form.addField('custpage_alphbets', 'radio','Beta','b');
                form.addField('custpage_alphbets', 'radio','Charlie','c');
                form.addField('custpage_alphbets', 'radio', 'Delta', 'd');
                form.addField('custpage_alphbets', 'radio','Echo','e');
                form.addField('custpage_alphbets', 'radio','Foxtrot','f'); 

                form.getField('custpage_alphbets', 'a').setDefaultValue('a');  //instead of setMandatory
                 
                var machine = form.addSubList('custpage_mysublist', 'inlineeditor', 'my sublist');
                
                var selectField = machine.addField('myselectfield', 'select', 'My Select Field');
                selectField.addSelectOption('1', 'One');
                selectField.addSelectOption('2', 'Two');
                selectField.addSelectOption('3', 'Three');
                
                form.addSubmitButton('submit');
                response.writePage(form);
        }
        else
        {
                
        }
}