parser.java

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					toAbsoluteURI(moldURI, true));
			for (Iterator e = params.entrySet().iterator(); e.hasNext();) {
				final Map.Entry me = (Map.Entry)e.next();
				compdef.addProperty(
					(String)me.getKey(), (String)me.getValue(), null);
			}
		} else if ("link".equals(target) || "meta".equals(target)) { //declare a header element
			pgdef.addHeader(new Header(target, params));
		} else if ("page".equals(target)) {
			log.warning("Ignored page directive at "+pi.getLocator());
		} else if ("import".equals(target)) { //import
			throw new UiException("The import directive can be used only at the top level, "+pi);
		} else {
			log.warning("Unknown processing instruction: "+target);
		}
	}
	private static void noEL(String nm, String val, Item item)
	throws UiException {
		if (val != null && val.indexOf("${") >= 0)
			throw new UiException(nm+" does not support EL expressions, "+item.getLocator());
	}
	private String toAbsoluteURI(String uri, boolean allowEL) {
		if (uri != null && uri.length() > 0) {
			final char cc = uri.charAt(0);
			if (cc != '/' && cc != '~' && (!allowEL || uri.indexOf("${") < 0)
			&& !Servlets.isUniversalURL(uri)) {
				final String dir = getLocator().getDirectory();
				if (dir != null && dir.length() > 0)
					return dir.charAt(dir.length() - 1) == '/' ?
							dir + uri: dir + '/' + uri;
			}
		}
		return uri;
	}

	/** Parses the specified elements.
	 */
	private void parse(PageDefinition pgdef, InstanceDefinition parent,
	Collection items, AnnotInfo annotInfo)
	throws Exception {
		for (Iterator it = items.iterator(); it.hasNext();) {
			final Object o = it.next();
			if (o instanceof Element) {
				parse(pgdef, parent, (Element)o, annotInfo);
			} else if (o instanceof ProcessingInstruction) {
				parse(pgdef, (ProcessingInstruction)o);
			} else if ((o instanceof Text) || (o instanceof CData)) {
				String label = ((Item)o).getText();

				final LanguageDefinition parentlang =
					getLanguageDefinition(pgdef, parent);
				if (!parentlang.isRawLabel())
					label = label.trim();

				if (label.trim().length() > 0) //consider as a label
					parentlang.newLabelDefinition(parent, label);
			}
		}
	}
	private static final
	LanguageDefinition getLanguageDefinition(PageDefinition pgdef,
	InstanceDefinition instdef) {
		for (; instdef != null; instdef = instdef.getParent()) {
			LanguageDefinition langdef = instdef.getLanguageDefinition();
			if (langdef != null)
				return langdef;
		}
		return pgdef.getLanguageDefinition();
	}

	/** Parse an component definition specified in the given element.
	 */
	private void parse(PageDefinition pgdef, InstanceDefinition parent,
	Element el, AnnotInfo annotInfo)
	throws Exception {
		final String nm = el.getLocalName();
		final Namespace ns = el.getNamespace();
		final String pref = ns != null ? ns.getPrefix(): "";
		final String uri = ns != null ? ns.getURI(): "";
		final LanguageDefinition langdef = pgdef.getLanguageDefinition();
		if ("zscript".equals(nm) && isZkElement(langdef, nm, pref, uri)) {
			parseZScript(parent, el, annotInfo);
		} else if ("attribute".equals(nm) && isZkElement(langdef, nm, pref, uri)) {
			parseAttribute(parent, el, annotInfo);
		} else if ("custom-attributes".equals(nm) && isZkElement(langdef, nm, pref, uri)) {
			parseCustomAttribute(parent, el, annotInfo);
		} else if (LanguageDefinition.ANNO_NAMESPACE.equals(uri)) {
			parseAnnotation(el, annotInfo);
		} else {
			//if (D.ON && log.debugable()) log.debug("component: "+nm+", ns:"+ns);

			final InstanceDefinition instdef;
			if ("zk".equals(nm) && isZkElement(langdef, nm, pref, uri)) {
				if (annotInfo.clear())
					log.warning("Annotations are ignored since <zk> doesn't support them, "+el.getLocator());

				instdef = new InstanceDefinition(
					parent, ComponentDefinition.ZK, "zk"); 
			} else {
				if (LanguageDefinition.ZK_NAMESPACE.equals(uri))
					throw new UiException("Unknown ZK component: "+el);

				final LanguageDefinition complangdef;
				if (isDefault(langdef, pref, uri)) {
					complangdef = langdef;
				} else {
					complangdef = LanguageDefinition.lookup(uri);
				}

				ComponentDefinition compdef =
					pgdef.getComponentDefinitionMap().get(nm);
				if (compdef != null) {
					instdef = new InstanceDefinition(parent, compdef);
				} else if (complangdef.hasComponentDefinition(nm)) {
					compdef = complangdef.getComponentDefinition(nm);
					instdef = new InstanceDefinition(parent, compdef);
				} else {
					compdef = complangdef.getDynamicTagDefinition();
					if (compdef == null)
						throw new DefinitionNotFoundException("Component definition not found: "+nm+" in "+complangdef);
					instdef = new InstanceDefinition(parent, compdef, nm);
				}

				//process use first because addProperty needs it
				final String use = el.getAttribute("use");
				if (!isEmpty(use)) {
					noEL("use", use, el);
					instdef.setImplementationClass(use);
						//Resolve later since might defined in zscript
				}
			}

			String ifc = null, unless = null,
				forEach = null, forEachBegin = null, forEachEnd = null;
			AnnotInfo attrAnnotInfo = null;
			for (Iterator it = el.getAttributeItems().iterator();
			it.hasNext();) {
				final Attribute attr = (Attribute)it.next();
				final Namespace attrns = attr.getNamespace();
				final String attnm = attr.getLocalName();
				final String attval = attr.getValue();
				if (attrns != null && LanguageDefinition.ANNO_NAMESPACE.equals(attrns.getURI())) {
					if (attrAnnotInfo == null)
						attrAnnotInfo = new AnnotInfo();
					attrAnnotInfo.addRaw(attnm, attval);
				} else if ("if".equals(attnm)) {
					ifc = attval;
				} else if ("unless".equals(attnm)) {
					unless = attval;
				} else if ("forEach".equals(attnm)) {
					forEach = attval;
				} else if ("forEachBegin".equals(attnm)) {
					forEachBegin = attval;
				} else if ("forEachEnd".equals(attnm)) {
					forEachEnd = attval;
				} else if (!"use".equals(attnm)) {
					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)) {
						addAttribute(instdef, attns, attnm, attval, null);
						if (attrAnnotInfo != null)
							attrAnnotInfo.updateAnnotations(instdef, attnm);
					}
				}
			}

			instdef.setCondition(ConditionImpl.getInstance(ifc, unless));
			instdef.setForEach(forEach, forEachBegin, forEachEnd);
			annotInfo.updateAnnotations(instdef, null);

			parse(pgdef, instdef, el.getChildren(), annotInfo); //recursive
		}
	}
	private void parseZScript(InstanceDefinition parent, Element el,
	AnnotInfo annotInfo) throws Exception {
		//if (!el.getElements().isEmpty())
		//	throw new UiException("Child elements are not allowed for the zscript element, "+el.getLocator());

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

		final String ifc = el.getAttribute("if"),
			unless = el.getAttribute("unless"),
			zsrc = el.getAttribute("src");

		final Condition cond = ConditionImpl.getInstance(ifc, unless);
		if (!isEmpty(zsrc)) {
			final ZScript zs;
			if (zsrc.indexOf("${") >= 0) {
				zs = new ZScript(zsrc, cond, getLocator());
			} else {
				final URL url = getLocator().getResource(zsrc);
				if (url == null) throw new FileNotFoundException("File not found: "+zsrc+", at "+el.getLocator());
				zs = new ZScript(url, cond);
			}

			parent.appendChild(zs);
		}

		final String script = el.getText(true);
		if (!isEmpty(script))
			parent.appendChild(new ZScript(script, cond));
	}
	private void parseAttribute(InstanceDefinition parent, Element el,
	AnnotInfo annotInfo) 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 attval = el.getText(false); //don't trim!!
		if (!isEmpty(attval)) {
			addAttribute(parent, null, attnm, attval,
				ConditionImpl.getInstance(
					el.getAttribute("if"), el.getAttribute("unless")));
		}

		annotInfo.updateAnnotations(parent, attnm);
	}
	private void parseCustomAttribute(InstanceDefinition parent, Element el,
	AnnotInfo annotInfo) throws Exception {
		//if (!el.getElements().isEmpty())
		//	throw new UiException("Child elements are not allowed for the custom-attributes element, "+el.getLocator());

		if (parent instanceof PageDefinition)
			throw new UiException("custom-attributes must be used under a component, "+el.getLocator());
		if (annotInfo.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.addCustomAttributes(
					new CustomAttributes(attrs, scope, ConditionImpl.getInstance(ifc, unless)));
	}
	private void parseAnnotation(Element el, AnnotInfo annotInfo)
	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());
		}
		annotInfo.add(el.getLocalName(), attrs);
	}

	/** Whether the name space belongs to the default language. */
	private static final
	boolean isDefault(LanguageDefinition langdef, String pref, String uri) {
		return ("".equals(pref) && "".equals(uri))
			|| langdef.getNamespace().equals(uri);
	}
	/** Whether a string is null or empty. */
	private static boolean isEmpty(String s) {
		return s == null || s.length() == 0;
	}
	/** Returns whether the element is conflict with the language definition.
	 * @param pref namespace's prefix
	 * @param uri namespace's URI
	 */
	private static final boolean
	isZkElement(LanguageDefinition langdef, String nm, String pref, String uri) {
		if (isDefault(langdef, pref, uri))
			return !langdef.hasComponentDefinition(nm);
		return LanguageDefinition.ZK_NAMESPACE.equals(uri);
	}

	/** Parse an attribute and adds it to the definition.
	 */
	private void addAttribute(InstanceDefinition instdef, Namespace attrns,
	String name, String value, Condition cond) throws Exception {
		if (Events.isValid(name)) {
			boolean bZkAttr = attrns == null;
			if (!bZkAttr) {
				final String pref = attrns.getPrefix(), uri = attrns.getURI();
				final LanguageDefinition langdef = instdef.getLanguageDefinition();
				if (langdef == null)
					bZkAttr = true;
				else if (isDefault(langdef, pref, uri))
					bZkAttr = !langdef.isDynamicReservedAttributes("[event]");
				else
					bZkAttr = LanguageDefinition.ZK_NAMESPACE.equals(uri);
			}
			if (bZkAttr) {
				instdef.addEventHandler(name, value, cond);
				return; //done
			}
		}
		instdef.addProperty(name, value, cond);
	}

	/** Information of annotations.
	 */
	private static class AnnotInfo {
		/** A list of Object[] = {String annotName, Map annotAttrs}; */
		final List _annots = new LinkedList();

		/** Adds an annotation definition. */
		private void add(String annotName, Map annotAttrs) {
			if (annotName == null || annotName.length() == 0)
				throw new IllegalArgumentException("empty");
			_annots.add(new Object[] {annotName, annotAttrs});
		}
		private void addRaw(String annotName, String rawValue) {
			final Map attrs = Maps.parse(null, rawValue, ',', '\'');
			add(annotName, attrs);
		}
		/** Updates the annotations to the specified instance definition.
		 * Note: it clears all annotation definitions before returning.
		 *
		 * @param instdef the instance definition to update
		 * @param propName the property name
		 */
		private void updateAnnotations(InstanceDefinition instdef, String propName) {
			for (Iterator it = _annots.iterator(); it.hasNext();) {
				final Object[] info = (Object[])it.next();
				final String annotName = (String)info[0];
				final Map annotAttrs = (Map)info[1];
				if (propName != null)
					instdef.addAnnotation(propName, annotName, annotAttrs);
				else
					instdef.addAnnotation(annotName, annotAttrs);
			}
			_annots.clear();
		}
		/** Clears all annotation definitions.
		 * @return true if one or more annotation definitions are defined
		 * (thru {@link #add}).
		 */
		private boolean clear() {
			if (!_annots.isEmpty()) {
				_annots.clear();
				return true;
			}
			return false;
		}
	}
}