parser.java

ZK 基础介绍 功能操作 模块 结合数据库操作

				} else if ("forEachEnd".equals(attnm) && isZkAttr(langdef, attrns)) {
					forEachEnd = attval;
				} else if ("fulfill".equals(attnm) && isZkAttr(langdef, attrns)) {
					compInfo.setFulfill(attval);
				} else if (!("use".equals(attnm) && isZkAttr(langdef, attrns))) {
					final Namespace attns = attr.getNamespace();
					final String attpref = attns != null ? attns.getPrefix(): "";
					final String attruri = attns != null ? attns.getURI(): "";
					if (!"xmlns".equals(attpref)
					&& !("xmlns".equals(attnm) && "".equals(attpref))
					&& !"http://www.w3.org/2001/XMLSchema-instance".equals(attruri)) {
						final int len = attval.length();
						if (len >= 3 && attval.charAt(0) == '@'
						&& attval.charAt(1) == '{' && attval.charAt(len-1) == '}') { //annotation
							if (attrAnnHelper == null)
								attrAnnHelper = new AnnotationHelper();
							attrAnnHelper.addByCompoundValue(
								attval.substring(2, len -1));
							attrAnnHelper.applyAnnotations(compInfo,
								"self".equals(attnm) ? null: attnm, true);
						} else {
							addAttribute(compInfo, attns, attnm, attval, null);
							if (attrAnnHelper != null)
								attrAnnHelper.applyAnnotations(compInfo, attnm, true);
						}
					}
				}
			}

			compInfo.setCondition(ConditionImpl.getInstance(ifc, unless));
			compInfo.setForEach(forEach, forEachBegin, forEachEnd);
			annHelper.applyAnnotations(compInfo, null, true);

			parse(pgdef, compInfo, el.getChildren(), annHelper); //recursive

			//optimize native components
			if (compInfo instanceof NativeInfo
			&& !compInfo.getChildren().isEmpty())
				optimizeNativeInfos((NativeInfo)compInfo);
		}
	}
	private void parseZScript(NodeInfo parent, Element el,
	AnnotationHelper annHelper) {
		if (el.getAttributeItem("forEach") != null)
			throw new UiException("forEach not applicable to <zscript>, "+el.getLocator());
		if (annHelper.clear())
			log.warning("Annotations are ignored since <zscript> doesn't support them, "+el.getLocator());

		final String
			ifc = el.getAttributeValue("if"),
			unless = el.getAttributeValue("unless"),
			zsrc = el.getAttributeValue("src");
		final boolean
			deferred = "true".equals(el.getAttributeValue("deferred"));

		String zslang = el.getAttributeValue("language");
		if (zslang == null) {
			zslang = parent.getPageDefinition().getZScriptLanguage();
			//we have to resolve it in parser since a page might be
			//created by use of createComponents
		} else {
			noEmpty("language", zslang, el);
			noEL("language", zslang, el);
		}

		final ConditionImpl cond = ConditionImpl.getInstance(ifc, unless);
		if (!isEmpty(zsrc)) { //ignore empty (not error)
			final ZScript zs;
			if (zsrc.indexOf("${") >= 0) {
				zs = new ZScript(parent.getEvaluatorRef(),
					zslang, zsrc, cond, getLocator());
			} else {
				final URL url = getLocator().getResource(zsrc);
				if (url == null) throw new UiException("File not found: "+zsrc+", at "+el.getLocator());
					//don't throw FileNotFoundException since Tomcat 'eats' it
				zs = new ZScript(parent.getEvaluatorRef(), zslang, url, cond);
			}

			if (deferred) zs.setDeferred(true);
			parent.appendChild(zs);
		}

		final String script = el.getText(true);
		if (!isEmpty(script)) {
			final ZScript zs =
				new ZScript(parent.getEvaluatorRef(), zslang, script, cond);
			if (deferred) zs.setDeferred(true);
			parent.appendChild(zs);
		}
	}
	private static void parseAttribute(ComponentInfo parent, Element el,
	AnnotationHelper annHelper) throws Exception {
		//if (!el.getElements().isEmpty())
		//	throw new UiException("Child elements are not allowed for the attribute element, "+el.getLocator());

		if (el.getAttributeItem("forEach") != null)
			throw new UiException("forEach not applicable to attribute, "+el.getLocator());

		//FUTURE: handling the namespace of if and unless
		final String attnm = IDOMs.getRequiredAttributeValue(el, "name");
		final String trim = el.getAttributeValue("trim");
		noEL("trim", trim, el);
		final String attval = el.getText(trim != null && "true".equals(trim));
		addAttribute(parent, null, attnm, attval,
			ConditionImpl.getInstance(
				el.getAttributeValue("if"), el.getAttributeValue("unless")));

		annHelper.applyAnnotations(parent, attnm, true);
	}
	private static void parseCustomAttributes(NodeInfo parent, Element el,
	AnnotationHelper annHelper) throws Exception {
		//if (!el.getElements().isEmpty())
		//	throw new UiException("Child elements are not allowed for <custom-attributes>, "+el.getLocator());

		if (parent instanceof PageDefinition)
			throw new UiException("custom-attributes must be used under a component, "+el.getLocator());
		if (annHelper.clear())
			log.warning("Annotations are ignored since <custom-attribute> doesn't support them, "+el.getLocator());

		String ifc = null, unless = null, scope = null;
		final Map attrs = new HashMap();
		for (Iterator it = el.getAttributeItems().iterator();
		it.hasNext();) {
			final Attribute attr = (Attribute)it.next();
			final String attnm = attr.getLocalName();
			final String attval = attr.getValue();
			if ("if".equals(attnm)) {
				ifc = attval;
			} else if ("unless".equals(attnm)) {
				unless = attval;
			} else if ("scope".equals(attnm)) {
				scope = attval;
			} else if ("forEach".equals(attnm)) {
				throw new UiException("forEach not applicable to <custom-attributes>, "+el.getLocator());
			} else {
				attrs.put(attnm, attval);
			}
		}

		if (!attrs.isEmpty())
			parent.appendChild(new AttributesInfo(
				parent.getEvaluatorRef(),
				attrs, scope, ConditionImpl.getInstance(ifc, unless)));
	}
	private static void parseVariables(NodeInfo parent, Element el,
	AnnotationHelper annHelper) throws Exception {
		//if (!el.getElements().isEmpty())
		//	throw new UiException("Child elements are not allowed for <variables> element, "+el.getLocator());

		if (el.getAttributeItem("forEach") != null)
			throw new UiException("forEach not applicable to <variables>, "+el.getLocator());
		if (annHelper.clear())
			log.warning("Annotations are ignored since <variables> doesn't support them, "+el.getLocator());

		String ifc = null, unless = null;
		boolean local = false;
		final Map vars = new HashMap();
		for (Iterator it = el.getAttributeItems().iterator();
		it.hasNext();) {
			final Attribute attr = (Attribute)it.next();
			final String attnm = attr.getLocalName();
			final String attval = attr.getValue();
			if ("if".equals(attnm)) {
				ifc = attval;
			} else if ("unless".equals(attnm)) {
				unless = attval;
			} else if ("local".equals(attnm)) {
				local = "true".equals(attval);
			} else if ("forEach".equals(attnm)) {
				throw new UiException("forEach not applicable to <variables>, "+el.getLocator());
			} else {
				vars.put(attnm, attval);
			}
		}
		if (!vars.isEmpty())
			parent.appendChild(new VariablesInfo(
				parent.getEvaluatorRef(),
				vars, local, ConditionImpl.getInstance(ifc, unless)));
	}
	private static void parseAnnotation(Element el, AnnotationHelper annHelper)
	throws Exception {
		if (!el.getElements().isEmpty())
			throw new UiException("Child elements are not allowed for the annotations, "+el.getLocator());

		final Map attrs = new HashMap();
		for (Iterator it = el.getAttributeItems().iterator();
		it.hasNext();) {
			final Attribute attr = (Attribute)it.next();
			attrs.put(attr.getLocalName(), attr.getValue());
		}
		annHelper.add(el.getLocalName(), attrs);
	}

	/** Whether a string is null or empty. */
	private static boolean isEmpty(String s) {
		return s == null || s.length() == 0;
	}
	/** Whether the name space belongs to the default language. */
	private static final
	boolean isDefaultNS(LanguageDefinition langdef, String pref, String uri) {
		return (!langdef.isNative() && "".equals(pref) && "".equals(uri))
			|| langdef.getNamespace().equals(uri);
	}
	/** Returns whether it is a ZK element.
	 * @param pref namespace's prefix
	 * @param uri namespace's URI
	 */
	private static final boolean
	isZkElement(LanguageDefinition langdef, String nm, String pref, String uri) {
		if (isDefaultNS(langdef, pref, uri))
			return !langdef.hasComponentDefinition(nm);
		return LanguageDefinition.ZK_NAMESPACE.equals(uri);
	}
	/** Returns whether it is a ZK attribute.
	 */
	private static final boolean
	isZkAttr(LanguageDefinition langdef, Namespace attrns) {
		//if native we will make sure URI is ZK or lang's namespace
		if (langdef.isNative()) {
			final String uri = attrns.getURI();
			return LanguageDefinition.ZK_NAMESPACE.equals(uri)
				|| langdef.getNamespace().equals(uri);
		}
		return true;
	}

	/** Parse an attribute and adds it to the definition.
	 */
	private static void addAttribute(ComponentInfo compInfo, Namespace attrns,
	String name, String value, ConditionImpl cond) throws Exception {
		if (Events.isValid(name)) {
			boolean bZkAttr = attrns == null;
			if (!bZkAttr) {
				String pref = attrns.getPrefix(), uri = attrns.getURI();
				LanguageDefinition langdef = compInfo.getLanguageDefinition();
				if (langdef == null)
					bZkAttr = true;
				else if (isDefaultNS(langdef, pref, uri))
					bZkAttr = !langdef.isDynamicReservedAttributes("[event]");
				else
					bZkAttr = LanguageDefinition.ZK_NAMESPACE.equals(uri);
			}
			if (bZkAttr) {
				final ZScript zscript = ZScript.parseContent(value);
				if (zscript.getLanguage() == null)
					zscript.setLanguage(
						compInfo.getPageDefinition().getZScriptLanguage());
						//resolve it here instead of runtime since createComponents
				compInfo.addEventHandler(name, zscript, cond);
				return; //done
			}
		}
		compInfo.addProperty(name, value, cond);
	}

	/** Adds the declared namespaces to the native info, if necessary.
	 */
	private static void addDeclaredNamespace(
	NativeInfo nativeInfo, Collection namespaces, LanguageDefinition langdef) {
		for (Iterator it = namespaces.iterator(); it.hasNext();) {
			final Namespace ns = (Namespace)it.next();
			final String uri = ns.getURI();
			boolean bNatPrefix =
				uri.startsWith(LanguageDefinition.NATIVE_NAMESPACE_PREFIX);
			if (bNatPrefix
			|| (langdef.isNative()
				&& !LanguageDefinition.ZK_NAMESPACE.equals(uri)
				&& !LanguageDefinition.ANNO_NAMESPACE.equals(uri)
				&& !LanguageDefinition.NATIVE_NAMESPACE.equals(uri)
				&& !langdef.getNamespace().equals(uri)))
				nativeInfo.addDeclaredNamespace(
					new Namespace(ns.getPrefix(),
						bNatPrefix ? uri.substring(LanguageDefinition.NATIVE_NAMESPACE_PREFIX.length()):
							uri));
		}
	}
	/** Minimizes the native infos such that UiEngine creates
	 * the minimal number of components.
	 */
	private static void optimizeNativeInfos(NativeInfo compInfo) {
		//Optimize 1: merge to prolog, if the first children are
		//native and have no child
		for (Iterator it = compInfo.getChildren().iterator(); it.hasNext();) {
			final Object o = it.next();
			if (o instanceof NativeInfo) {
				final NativeInfo childInfo = (NativeInfo)o;
				if (!childInfo.getChildren().isEmpty())
					break;
				childInfo.setParentDirectly(null);
			} else if (o instanceof ComponentInfo) {
				break;
			}

			compInfo.addPrologChildDirectly(o);
			it.remove(); //detach it from the children list
		}

		//Optimize 2: merge to epilog if the last children, are
		//native and have no child
		int sz = compInfo.getChildren().size();
		if (sz >= 0) {
			final ListIterator it = compInfo.getChildren().listIterator(sz);
			while (it.hasPrevious()) {
				final Object o = it.previous();
				if (o instanceof NativeInfo) {
					final NativeInfo childInfo = (NativeInfo)o;
					if (!childInfo.getChildren().isEmpty()) {
						it.next();
						break;
					}
					childInfo.setParentDirectly(null);
				} else if (o instanceof ComponentInfo) {
					it.next();
					break;
				}
			}
			while (it.hasNext()) {
				final Object o = it.next();
				compInfo.addEpilogChildDirectly(o);
				it.remove();
			}
		}

		//Optimize 3: merge to split child
		//If there is only one native child, we make it a split child and
		//make all its children (grand-chidren) up one level
		if (compInfo.getChildren().size() == 1 && !compInfo.withForEach()
		&& compInfo.getSplitChild() == null /*just in case*/) {
			Iterator it = compInfo.getChildren().iterator();
			final Object o = it.next();
			if (o instanceof NativeInfo) {
				final NativeInfo childInfo = (NativeInfo)o;
				childInfo.setParentDirectly(null);
				compInfo.setSplitChild(childInfo);
				it.remove();

				for (it = childInfo.getChildren().iterator(); it.hasNext();) {
					final Object gc = it.next();
					it.remove();
					compInfo.appendChildDirectly(gc);
					if (gc instanceof ComponentInfo)
						((ComponentInfo)gc).setParentDirectly(compInfo);
				}
			}
		}
	}
}