Standard XML Representations of Field Data

I2CE_FormField

• add in a (final) method getXMLData($as_node = false). Calls _getXMLData(). If $as_node == false, the simply pass it along. If $as_node == true, first convert it to a DOMNode and return that
• add in a abstract method _getXMLData() which return strings

Sub-Classes of I2CE_FormField

• each non-abstract class should implement _getXMLData()

XML Format

Each _getXMLData() should return a string that looks like <value type='XXX'>YYYY<value> where XXX is the form field type such as MAP, STRING, DATE_YMD, etc and YYY is as defined below