snaker-core/src/main/java/org/snaker/engine/parser/AbstractNodeParser.java
public void parse(Element element) {
		model = newModel();
		model.setName(element.getAttribute(ATTR_NAME));
		model.setDisplayName(element.getAttribute(ATTR_DISPLAYNAME));
		model.setLayout(element.getAttribute(ATTR_LAYOUT));
		model.setPreInterceptors(element.getAttribute(ATTR_PREINTERCEPTORS));
		model.setPostInterceptors(element.getAttribute(ATTR_POSTINTERCEPTORS));
		
		List<Element> transitions = XmlHelper.elements(element, NODE_TRANSITION);
		for(Element te : transitions) {
			TransitionModel transition = new TransitionModel();
			transition.setName(te.getAttribute(ATTR_NAME));
			transition.setDisplayName(te.getAttribute(ATTR_DISPLAYNAME));
			transition.setTo(te.getAttribute(ATTR_TO));
			transition.setExpr(te.getAttribute(ATTR_EXPR));
			transition.setG(te.getAttribute(ATTR_G));
			transition.setOffset(te.getAttribute(ATTR_OFFSET));
			transition.setSource(model);
			model.getOutputs().add(transition);
		}
		
		parseNode(model, element);
	}
public void parse(Element element) {
		model = newModel();
		model.setName(element.getAttribute(ATTR_NAME));
		model.setDisplayName(element.getAttribute(ATTR_DISPLAYNAME));
		model.setLayout(element.getAttribute(ATTR_LAYOUT));
		model.setPreInterceptors(element.getAttribute(ATTR_PREINTERCEPTORS));
		model.setPostInterceptors(element.getAttribute(ATTR_POSTINTERCEPTORS));
		
		List<Element> transitions = XmlHelper.elements(element, NODE_TRANSITION);
		for(Element te : transitions) {
			TransitionModel transition = new TransitionModel();
			transition.setName(te.getAttribute(ATTR_NAME));
			transition.setDisplayName(te.getAttribute(ATTR_DISPLAYNAME));
			transition.setTo(te.getAttribute(ATTR_TO));
			transition.setExpr(te.getAttribute(ATTR_EXPR));
			transition.setG(te.getAttribute(ATTR_G));
			transition.setOffset(te.getAttribute(ATTR_OFFSET));
			transition.setSource(model);
			model.getOutputs().add(transition);
		}
		
		parseNode(model, element);
	}
实现NodeParser接口的parse函数
由子类产生各自的模型对象，设置常用的名称属性，并且解析子节点transition，构造TransitionModel模型对象