Extending : Data type extension : Implementing data type extension : Implementing a widget to display a type : Extend the UDTT JSP tag handler for the TextBox widget
  
Extend the UDTT JSP tag handler for the TextBox widget
To extend the UDTT JSP tag handler for the TextBox widget, a technical developer must extend the com.ibm.btt.dojo.tag.DojoTextBoxTag class and override the getWidgetType method. So DOJO widget class for the new type can be returned if the dataName of the TextBox widget is in this type.
Shown below is a simple code of implementation:
protected String getWidgetType(String type) {
    if ("TimeZone".equalsIgnoreCase(type)) {
      return "com.ibm.btt.dijit.TimeZoneTextBox";
    }
    else{
      return super.getWidgetType(type);
    }
  }
See also
Implementing a widget to display a type