deserialize method
Deserializes the FML template elements, attributes and children
Implementation
@override
void deserialize(XmlElement xml) {
// deserialize
super.deserialize(xml);
// set properties
value = Xml.get(node: xml, tag: 'value');
layout = Xml.get(node: xml, tag: 'layout');
center = Xml.get(node: xml, tag: 'center');
wrap = Xml.get(node: xml, tag: 'wrap');
size = Xml.get(node: xml, tag: 'size');
// build radio options
_buildOptions();
// set the default selected option
if (datasource == null) _setSelectedOption();
}