public PageImpl(PageDefinition pgdef) 
{
	                                                                             	 
		this(pgdef.getLanguageDefinition(), pgdef.getComponentDefinitionMap(),
			pgdef.getRequestPath(), pgdef.getZScriptLanguage());
}

Constructs a page by giving the page definition.

Note: when a page is constructed, it doesn't belong to a desktop yet. Caller has to invoke #init to complete the creation of a page. Why two phase? Contructor could be called before execution is activated, but #init must be called in an execution.

Also note that #getId and #getTitle are not ready until #init is called.

Parameters:

pgdef - the page definition (never null).

 public PageImpl(Richlet richlet,
    String path) 
{
		init();
		_langdef = richlet.getLanguageDefinition();
		_cplURI = new ExValue(_langdef.getCompleteURI(), String.class);
		_dkURI = new ExValue(_langdef.getDesktopURI(), String.class);
		_pgURI = new ExValue(_langdef.getPageURI(), String.class);
		_compdefs = new ComponentDefinitionMap(
			_langdef.getComponentDefinitionMap().isCaseInsensitive());
		_path = path != null ? path: "";
		_zslang = "Java";
}

Constructs a page by specifying a richlet.

Note: when a page is constructed, it doesn't belong to a desktop yet. Caller has to invoke #init to complete the creation of a page.

Also note that #getId and #getTitle are not ready until #init is called.

Parameters:

richlet - the richlet to serve this page.

path - the request path, or null if not available

 public PageImpl(LanguageDefinition langdef,
    ComponentDefinitionMap compdefs,
    String path,
    String zslang) 
{
		init();
		_langdef = langdef;
		_cplURI = new ExValue(_langdef.getCompleteURI(), String.class);
		_dkURI = new ExValue(_langdef.getDesktopURI(), String.class);
		_pgURI = new ExValue(_langdef.getPageURI(), String.class);
		_compdefs = compdefs != null ? compdefs:
			new ComponentDefinitionMap(
				_langdef.getComponentDefinitionMap().isCaseInsensitive());
		_path = path != null ? path: "";
		_zslang = zslang != null ? zslang: "Java";
}

Constructs a page without page definition and richlet.

Parameters:

langdef - the language definition (never null)

compdefs - the component definition map. If null, an empty map is assumed.

path - the request path. If null, empty is assumed.

zslang - the zscript language. If null, "Java" is assumed.

 public  void addDeferredZScript(Component parent,
    ZScript zscript) 
{
		if (zscript != null) {
			if (_zsDeferred == null)
				_zsDeferred = new LinkedList();
			_zsDeferred.add(new Object[] {parent, zscript});
		}
}

 public boolean addEventListener(String evtnm,
    EventListener listener) 
{
		if (evtnm == null || listener == null)
			throw new IllegalArgumentException("null");
		if (!Events.isValid(evtnm))
			throw new IllegalArgumentException("Invalid event name: "+evtnm);
		if (_listeners == null)
			_listeners = new HashMap(3);
		List l = (List)_listeners.get(evtnm);
		if (l != null) {
			for (Iterator it = l.iterator(); it.hasNext();) {
				final EventListener li = (EventListener)it.next();
				if (listener.equals(li))
					return false;
			}
		} else {
			_listeners.put(evtnm, l = new LinkedList());
		}
		l.add(listener);
		return true;
}

 public  void addFellow(Component comp) 
{
		final String compId = comp.getId();
		assert D.OFF || !ComponentsCtrl.isAutoId(compId);
		final Object old = _fellows.put(compId, comp);
		if (old != comp) { //possible due to recursive call
			if (old != null) {
				_fellows.put(((Component)old).getId(), old); //recover
				throw new InternalError("Called shall prevent replicated ID for roots");
			}
		}
}

 public  void addFunctionMapper(FunctionMapper mapper) 
{
		_mapper = DualFunctionMapper.combine(mapper, _mapper);
}

 public  void addRoot(Component comp) 
{
		assert D.OFF || comp.getParent() == null;
		for (Iterator it = _roots.iterator(); it.hasNext();)
			if (comp == it.next())
				return;
		_roots.add(comp);
}

 public boolean addVariableResolver(VariableResolver resolver) 
{
		if (resolver == null)
			throw new IllegalArgumentException("null");
		if (_resolvers == null)
			_resolvers = new LinkedList();
		else if (_resolvers.contains(resolver))
			return false;
		_resolvers.add(0, resolver); //FILO order
		return true;
}

 public boolean containsVariable(String name) 
{
		return _ns.containsVariable(name, true);
}

 public  void destroy() 
{
		for (Iterator it = getLoadedInterpreters().iterator(); it.hasNext();) {
			final Interpreter ip = (Interpreter)it.next();
			try {
				ip.destroy();
			} catch (Throwable ex) {
				log.error("Failed to destroy "+ip, ex);
			}
		}
		_ips.clear();
		//theorectically, the following is not necessary, but, to be safe...
		_roots.clear();
		_attrs.clear();
		_fellows = new HashMap(1); //not clear() since # of fellows might huge
		_ips = null; //not clear since it is better to NPE than memory leak
		_desktop = null;
		_owner = _defparent = null;
		_listeners = null;
		_ns = null;
		_resolvers = null;
}

 public Object getAttribute(String name) 
{
		return _attrs.get(name);
}

 public Object getAttribute(String name,
    int scope) 
{
		return getAttributes(scope).get(name);
}

 public Map getAttributes() 
{
		return _attrs;
}

 public Map getAttributes(int scope) 
{
		switch (scope) {
		case DESKTOP_SCOPE:
			return _desktop != null ?
				_desktop.getAttributes(): Collections.EMPTY_MAP;
		case SESSION_SCOPE:
			return _desktop != null ?
				_desktop.getSession().getAttributes(): Collections.EMPTY_MAP;
		case APPLICATION_SCOPE:
			return _desktop != null ?
				_desktop.getWebApp().getAttributes(): Collections.EMPTY_MAP;
		case PAGE_SCOPE:
			return _attrs;
		case REQUEST_SCOPE:
			final Execution exec = getExecution();
			if (exec != null) return exec.getAttributes();
			//fall thru
		default:
			return Collections.EMPTY_MAP;
		}
}

 public Boolean getCacheable() 
{
		return _cacheable;
}

 public ComponentDefinition getComponentDefinition(String name,
    boolean recur) 
{
		final ComponentDefinition compdef = _compdefs.get(name);
		if (!recur || compdef != null)
			return compdef;
		try {
			return _langdef.getComponentDefinition(name);
		} catch (DefinitionNotFoundException ex) {
		}
		return null;
}

 public ComponentDefinition getComponentDefinition(Class cls,
    boolean recur) 
{
		final ComponentDefinition compdef = _compdefs.get(cls);
		if (!recur || compdef != null)
			return compdef;
		try {
			return _langdef.getComponentDefinition(cls);
		} catch (DefinitionNotFoundException ex) {
		}
		return null;
}

 public ComponentDefinitionMap getComponentDefinitionMap() 
{
		return _compdefs;
}

 public String getContentType() 
{
		return _contentType;
}

 public Component getDefaultParent() 
{
 		return _defparent;
}

 public final Desktop getDesktop() 
{
		return _desktop;
}

 public String getDocType() 
{
		return _docType;
}

 public Object getELVariable(String name) 
{
		return getXelVariable(name);
}

 public Class getExpressionFactoryClass() 
{
		return _expfcls;
}

 public Component getFellow(String compId) 
{
		final Component comp = (Component)_fellows.get(compId);
		if (comp == null)
			if (compId != null && ComponentsCtrl.isAutoId(compId))
				throw new ComponentNotFoundException(MZk.AUTO_ID_NOT_LOCATABLE, compId);
			else
				throw new ComponentNotFoundException("Fellow component not found: "+compId);
		return comp;
}

 public Component getFellowIfAny(String compId) 
{
		return (Component)_fellows.get(compId);
}

 public Collection getFellows() 
{
		return Collections.unmodifiableCollection(_fellows.values());
}

 public String getFirstLine() 
{
		return _firstLine;
}

 public final FunctionMapper getFunctionMapper() 
{
		return _mapper;
}

 public String getHeaders() 
{
	   
		return _headers;
}

 public final String getId() 
{
		return _id;
}

 public Interpreter getInterpreter(String zslang) 
{
		zslang = (zslang != null ? zslang: _zslang).toLowerCase();
		Interpreter ip = (Interpreter)_ips.get(zslang);
		if (ip == null) {
			ip = Interpreters.newInterpreter(zslang, this);
			_ips.put(zslang, ip);
				//set first to avoid dead loop if script calls interpret again
			final String script = _langdef.getInitScript(zslang);
			if (script != null) {
				_ns.setVariable("log", _zklog, true);
				_ns.setVariable("page", this, true);
				ip.interpret(script, _ns);
			}
			//evaluate deferred zscripts, if any
			try {
				evalDeferredZScripts(ip, zslang);
			} catch (IOException ex) {
				throw new UiException(ex);
			}
		}
		return ip;
}

 public LanguageDefinition getLanguageDefinition() 
{
		return _langdef;
}

 public Iterator getListenerIterator(String evtnm) 
{
		if (_listeners != null) {
			final List l = (List)_listeners.get(evtnm);
			if (l != null)
				return new ListenerIterator(l);
		}
		return CollectionsX.EMPTY_ITERATOR;
}

 public Collection getLoadedInterpreters() 
{
		return _ips != null ? _ips.values(): Collections.EMPTY_LIST; //just in case
}

 public final Namespace getNamespace() 
{
		return _ns;
}

 public final Component getOwner() 
{
		return _owner;
}

 public String getRequestPath() 
{
		return _path;
}

 public String getRootAttributes() 
{
		return _rootAttrs;
}

 public Collection getRoots() 
{
		return _roRoots;
}

 public String getStyle() 
{
		return _style;
}

 public String getTitle() 
{
		return _title;
}

 public final String getUuid() 
{
		return _uuid;
}

 public Object getVariable(String name) 
{
		return _ns.getVariable(name, true);
}

 public Object getXelVariable(String name) 
{
		final VariableResolver resolv =
			getExecution().getVariableResolver();
		return resolv != null ? resolv.resolveVariable(name): null;
}

 public Class getZScriptClass(String clsnm) 
{
		for (Iterator it = getLoadedInterpreters().iterator();
		it.hasNext();) {
			Class cls = ((Interpreter)it.next()).getClass(clsnm);
			if (cls != null)
				return cls;
		}
		try {
			return Classes.forNameByThread(clsnm);
		} catch (ClassNotFoundException ex) {
			return null;
		}
}

 public Function getZScriptFunction(String name,
    Class[] argTypes) 
{
		for (Iterator it = getLoadedInterpreters().iterator();
		it.hasNext();) {
			Function mtd =
				((Interpreter)it.next()).getFunction(name, argTypes);
			if (mtd != null)
				return mtd;
		}
		return null;
}

 public Function getZScriptFunction(Namespace ns,
    String name,
    Class[] argTypes) 
{
		for (Iterator it = getLoadedInterpreters().iterator();
		it.hasNext();) {
			final Object ip = it.next();
			Function mtd =
				ip instanceof HierachicalAware ?
				((HierachicalAware)ip).getFunction(ns, name, argTypes):
				((Interpreter)ip).getFunction(name, argTypes);
			if (mtd != null)
				return mtd;
		}
		return null;
}

 public Function getZScriptFunction(Component comp,
    String name,
    Class[] argTypes) 
{
		return getZScriptFunction(comp != null ? comp.getNamespace(): null,
			name, argTypes);
}

 public String getZScriptLanguage() 
{
		return _zslang;
}

 public Method getZScriptMethod(String name,
    Class[] argTypes) 
{
		final Function fun = getZScriptFunction(name, argTypes);
		return fun != null ? new FuncMethod(fun): null;
}

 public Method getZScriptMethod(Namespace ns,
    String name,
    Class[] argTypes) 
{
		final Function fun = getZScriptFunction(ns, name, argTypes);
		return fun != null ? new FuncMethod(fun): null;
}

 public Object getZScriptVariable(String name) 
{
		for (Iterator it = getLoadedInterpreters().iterator();
		it.hasNext();) {
			final Object val = ((Interpreter)it.next()).getVariable(name);
			if (val != null)
				return val;
		}
		return null;
}

 public Object getZScriptVariable(Namespace ns,
    String name) 
{
		for (Iterator it = getLoadedInterpreters().iterator();
		it.hasNext();) {
			final Object ip = it.next();
			final Object val = ip instanceof HierachicalAware ?
				((HierachicalAware)ip).getVariable(ns, name):
				((Interpreter)ip).getVariable(name);
			if (val != null)
				return val;
		}
		return null;
}

 public Object getZScriptVariable(Component comp,
    String name) 
{
		return getZScriptVariable(comp != null ? comp.getNamespace(): null,
			name);
}

 public boolean hasFellow(String compId) 
{
		return _fellows.containsKey(compId);
}

 protected  void init() 
{
		_ips = new LinkedHashMap(3);
		_ns = new NS();
		_roRoots = Collections.unmodifiableList(_roots);
		_attrs = new HashMap();
		_fellows = new HashMap();
}

Initialized the page when contructed or deserialized.

 public  void init(PageConfig config) 
{
		if (_desktop != null)
			throw new IllegalStateException("Don't init twice");
		final Execution exec = Executions.getCurrent();
		_desktop = exec.getDesktop();
		if (_desktop == null)
			throw new IllegalArgumentException("null desktop");
		initVariables();
		if (((ExecutionCtrl)exec).isRecovering()) {
			final String uuid = config.getUuid(), id = config.getId();
			if (uuid == null || id == null)
				throw new IllegalArgumentException("both id and uuid are required in recovering");
			_uuid = uuid;
			_id = id;
		} else {
			final IdGenerator idgen =
				((WebAppCtrl)_desktop.getWebApp()).getIdGenerator();
			if (idgen != null)
				_uuid = idgen.nextPageUuid(this);
			if (_uuid == null)
				_uuid = ((DesktopCtrl)_desktop).getNextUuid();
			if (_id == null) {
				final String id = config.getId();
				if (id != null && id.length() != 0) _id = id;
			}
			if (_id != null)
				_id = (String)exec.evaluate(this, _id, String.class);
			if (_id != null && _id.length() != 0) {
				final String INVALID = ".&\\%";
				if (Strings.anyOf(_id, INVALID, 0) <  _id.length())
					throw new IllegalArgumentException("Invalid page ID: "+_id+". Invalid characters: "+INVALID);
			} else {
				_id = _uuid;
			}
		}
		String s = config.getHeaders();
		if (s != null) _headers = s;
		if (_title.length() == 0) {
			s = config.getTitle();
			if (s != null) setTitle(s);
		}
		if (_style.length() == 0) {
			s = config.getStyle();
			if (s != null) setStyle(s);
		}
		((DesktopCtrl)_desktop).addPage(this);
}

 public  void interpret(String zslang,
    String script,
    Namespace ns) 
{
		getInterpreter(zslang).interpret(script, ns);
}

 public  void invalidate() 
{
		getUiEngine().addInvalidate(this);
}

 public boolean isComplete() 
{
		return _complete;
}

 public boolean isListenerAvailable(String evtnm) 
{
		if (_listeners != null) {
			final List l = (List)_listeners.get(evtnm);
			return l != null && !l.isEmpty();
		}
		return false;
}

 public  void moveRoot(Component comp,
    Component refRoot) 
{
		if (comp.getPage() != this || comp.getParent() != null)
			return; //nothing to do
		boolean added = false, found = false;
		for (ListIterator it = _roots.listIterator(); it.hasNext();) {
			final Object o = it.next();
			if (o == comp) {
				if (!added) {
					if (!it.hasNext()) return; //last
					if (it.next() == refRoot) return; //same position
					it.previous(); it.previous(); it.next(); //restore cursor
				}
				it.remove();
				found = true;
				if (added || refRoot == null) break; //done
			} else if (o == refRoot) {
				it.previous();
				it.add(comp);
				it.next();
				added = true;
				if (found) break; //done
			}
		}
		if (!added) _roots.add(comp);
}

 public  void redraw(Collection responses,
    Writer out) throws IOException 
{
		if (log.debugable()) log.debug("Redrawing page: "+this+", roots="+_roots);
		final Execution exec = getExecution();
		final ExecutionCtrl execCtrl = (ExecutionCtrl)exec;
		final boolean asyncUpdate = execCtrl.getVisualizer().isEverAsyncUpdate();
		final boolean bIncluded = asyncUpdate || exec.isIncluded()
			|| exec.getAttribute(ATTR_REDRAW_BY_INCLUDE) != null;
		final String uri = (String)
			(_complete ? _cplURI: bIncluded ? _pgURI: _dkURI)
				.getValue(_langdef.getEvaluator(), this);
				//desktop and page URI is defined in language
		final Map attrs = new HashMap(6);
		attrs.put("page", this);
		attrs.put("asyncUpdate", Boolean.valueOf(asyncUpdate));
		attrs.put("action", "/"); //A non-empty string (backward compatible)
		attrs.put("responses",
			responses != null ? responses: Collections.EMPTY_LIST);
		if (bIncluded) {
			attrs.put("included", "true");
				//maintain original state since desktop will include page...
			exec.include(out, uri, attrs, Execution.PASS_THRU_ATTR);
		} else {
//FUTURE: Consider if config.isKeepDesktopAcrossVisits() implies cacheable
//Why yes: the client doesn't need to ask the server for updated content
//Why no: browsers seems fail to handle DHTML correctly (when BACK to
//a DHTML page), so it is better to let the server handle cache, if any
			final boolean cacheable =
				_cacheable != null ?  _cacheable.booleanValue():
					_desktop.getDevice().isCacheable();
			if (!cacheable) {
				//Bug 1520444
				execCtrl.setHeader("Pragma", "no-cache");
				execCtrl.addHeader("Cache-Control", "no-cache");
				execCtrl.addHeader("Cache-Control", "no-store");
				//execCtrl.addHeader("Cache-Control", "private");
				//execCtrl.addHeader("Cache-Control", "max-age=0");
				//execCtrl.addHeader("Cache-Control", "s-maxage=0");
				//execCtrl.addHeader("Cache-Control", "must-revalidate");
				//execCtrl.addHeader("Cache-Control", "proxy-revalidate");
				//execCtrl.addHeader("Cache-Control", "post-check=0");
				//execCtrl.addHeader("Cache-Control", "pre-check=0");
				execCtrl.setHeader("Expires", "-1");
				exec.setAttribute(Attributes.NO_CACHE, Boolean.TRUE);
				//so ZkFns.outLangJavaScripts generates zk.keepDesktop correctly
			}
			exec.forward(out, uri, attrs, Execution.PASS_THRU_ATTR);
				//Don't use include. Otherwise, headers will be gone.
		}
}

 public Object removeAttribute(String name) 
{
		return _attrs.remove(name);
}

 public Object removeAttribute(String name,
    int scope) 
{
			final Map attrs = getAttributes(scope);
			if (attrs == Collections.EMPTY_MAP)
				throw new IllegalStateException("This component doesn't belong to any ID space: "+this);
		return attrs.remove(name);
}

 public  void removeComponents() 
{
		for (Iterator it = new ArrayList(getRoots()).iterator();
		it.hasNext();)
			((Component)it.next()).detach();
}

 public boolean removeEventListener(String evtnm,
    EventListener listener) 
{
		if (evtnm == null || listener == null)
			throw new NullPointerException();
		if (_listeners != null) {
			final List l = (List)_listeners.get(evtnm);
			if (l != null) {
				for (Iterator it = l.iterator(); it.hasNext();) {
					final EventListener li = (EventListener)it.next();
					if (listener.equals(li)) {
						if (l.size() == 1)
							_listeners.remove(evtnm);
						else
							it.remove();
						return true;
					}
				}
			}
		}
		return false;
}

 public  void removeFellow(Component comp) 
{
		_fellows.remove(comp.getId());
}

 public  void removeRoot(Component comp) 
{
		for (Iterator it = _roots.iterator(); it.hasNext();)
			if (comp == it.next()) {
				it.remove();
				return;
			}
}

 public boolean removeVariableResolver(VariableResolver resolver) 
{
		return _resolvers != null && _resolvers.remove(resolver);
}

 public Class resolveClass(String clsnm) throws ClassNotFoundException 
{
		try {
			return Classes.forNameByThread(clsnm);
		} catch (ClassNotFoundException ex) {
			for (Iterator it = getLoadedInterpreters().iterator();
			it.hasNext();) {
				final Class c = ((Interpreter)it.next()).getClass(clsnm);
				if (c != null)
					return c;
			}
			throw ex;
		}
}

 public  void sessionDidActivate(Desktop desktop) 
{
		_desktop = desktop;
		if (_ownerUuid != null) {
			_owner = _desktop.getComponentByUuid(_ownerUuid);
			_ownerUuid = null;
		}
		for (Iterator it = _roots.iterator(); it.hasNext();)
			((ComponentCtrl)it.next()).sessionDidActivate(this);
		initVariables(); //since some variables depend on desktop
}

 public  void sessionWillPassivate(Desktop desktop) 
{
		for (Iterator it = _roots.iterator(); it.hasNext();)
			((ComponentCtrl)it.next()).sessionWillPassivate(this);
}

 public Object setAttribute(String name,
    Object value) 
{
		return value != null ? _attrs.put(name, value): removeAttribute(name);
}

 public Object setAttribute(String name,
    Object value,
    int scope) 
{
		if (value != null) {
			final Map attrs = getAttributes(scope);
			if (attrs == Collections.EMPTY_MAP)
				throw new IllegalStateException("This component doesn't belong to any ID space: "+this);
			return attrs.put(name, value);
		} else {
			return removeAttribute(name, scope);
		}
}

 public  void setCacheable(Boolean cacheable) 
{
		_cacheable = cacheable;
}

 public  void setComplete(boolean complete) 
{
		_complete = complete;
}

 public  void setContentType(String contentType) 
{
		_contentType = contentType;
}

 public  void setDefaultParent(Component comp) 
{
 		_defparent = comp;
}

 public  void setDocType(String docType) 
{
		_docType = docType;
}

 public  void setExpressionFactoryClass(Class expfcls) 
{
		if (expfcls != null && !ExpressionFactory.class.isAssignableFrom(expfcls))
			throw new IllegalArgumentException(expfcls+" must implement "+ExpressionFactory.class);
		_expfcls = expfcls;
}

 public  void setFirstLine(String firstLine) 
{
		_firstLine = firstLine;
}

 public  void setId(String id) 
{
		if (_desktop != null)
			throw new UiException("Unable to change the identifier after the page is initialized");
		if (id != null && id.length()  > 0) _id = id;
		//No need to update client since it is allowed only before init(...)
}

 public final  void setOwner(Component comp) 
{
		if (_owner != null)
			throw new IllegalStateException("owner can be set only once");
		_owner = comp;
}

 public  void setRootAttributes(String rootAttrs) 
{
		_rootAttrs = rootAttrs != null ? rootAttrs: "";
}

 public  void setStyle(String style) 
{
		if (style == null) style = "";
		if (!_style.equals(style)) {
			_style = style;
			if (_desktop != null) {
				final Execution exec = getExecution();
				if (_style.length()  > 0) {
					_style = (String)exec.evaluate(this, _style, String.class);
					if (_style == null) _style = "";
				}
				//FUTURE: might support the change of style dynamically
			}
		}
}

 public  void setTitle(String title) 
{
		if (title == null) title = "";
		if (!_title.equals(title)) {
			_title = title;
			if (_desktop != null) {
				final Execution exec = getExecution();
				if (_title.length()  > 0) {
					_title = (String)exec.evaluate(this, _title, String.class);
					if (_title == null) _title = "";
				}
				if (exec.isAsyncUpdate(this))
					getUiEngine().addResponse("setTitle", new AuSetTitle(_title));
			}
		}
}

 public  void setVariable(String name,
    Object val) 
{
		_ns.setVariable(name, val, true);
}

 public  void setZScriptLanguage(String zslang) throws InterpreterNotFoundException 
{
		if (!Objects.equals(zslang, _zslang)) {
			if (!Interpreters.exists(zslang))
				throw new InterpreterNotFoundException(zslang, MZk.NOT_FOUND, zslang);
			_zslang = zslang;
		}
}

 public String toString() 
{
		return "[Page "+_id+']";
}

 public  void unsetVariable(String name) 
{
		_ns.unsetVariable(name, true);
}