uiengineimpl.java

ZK 基础介绍 功能操作 模块 结合数据库操作

		}
	}

	private static final Event nextEvent(UiVisualizer uv) {
		final Event evt = ((ExecutionCtrl)uv.getExecution()).getNextEvent();
		return evt != null && !uv.isAborting() ? evt: null;
	}
	/** Cycle 1:
	 * Creates all child components defined in the specified definition.
	 * @return the first component being created.
	 */
	private static final Component[] execCreate(
	CreateInfo ci, NodeInfo parentInfo, Component parent)
	throws IOException {
		if (parentInfo instanceof ComponentInfo) {
			final ComponentInfo pi = (ComponentInfo)parentInfo;
			final String fulfill = pi.getFulfill();
			if (fulfill != null) { //defer the creation of children
				new FulfillListener(fulfill, pi, parent);
				return new Component[0];
			}
		}
		return execCreate0(ci, parentInfo, parent);
	}
	private static final Component[] execCreate0(
	CreateInfo ci, NodeInfo parentInfo, Component parent)
	throws IOException {
		final List created = new LinkedList();
		final Page page = ci.page;
		final PageDefinition pagedef = parentInfo.getPageDefinition();
			//note: don't use page.getDefinition because createComponents
			//might be called from a page other than instance's
		for (Iterator it = parentInfo.getChildren().iterator(); it.hasNext();) {
			final Object meta = it.next();
			if (meta instanceof ComponentInfo) {
				final ComponentInfo childInfo = (ComponentInfo)meta;
				final ForEach forEach = childInfo.getForEach(page, parent);
				if (forEach == null) {
					if (isEffective(childInfo, page, parent)) {
						final Component[] children =
							execCreateChild(ci, parent, childInfo);
						for (int j = 0; j < children.length; ++j)
							created.add(children[j]);
					}
				} else {
					while (forEach.next()) {
						if (isEffective(childInfo, page, parent)) {
							final Component[] children =
								execCreateChild(ci, parent, childInfo);
							for (int j = 0; j < children.length; ++j)
								created.add(children[j]);
						}
					}
				}
			} else if (meta instanceof TextInfo) {
				//parent must be a native component
				final String s = ((TextInfo)meta).getValue(parent);
				if (s != null && s.length() > 0)
					parent.appendChild(
						((Native)parent).getHelper().newNative(s));
			} else {
				execNonComponent(ci, parent, meta);
			}
		}
		return (Component[])created.toArray(new Component[created.size()]);
	}
	private static Component[] execCreateChild(
	CreateInfo ci, Component parent, ComponentInfo childInfo)
	throws IOException {
		final ComponentDefinition childdef = childInfo.getComponentDefinition();
		if (ComponentDefinition.ZK == childdef) {
			return execCreate(ci, childInfo, parent);
		} else if (childdef.isInlineMacro()) {
			final Map props = new HashMap();
			props.put("includer", parent);
			childInfo.evalProperties(props, ci.page, parent, true);
			return new Component[] {
				ci.exec.createComponents(childdef.getMacroURI(), parent, props)};
		} else {
			final Component child = execCreateChild0(ci, parent, childInfo);
			return child != null ? new Component[] {child}: new Component[0];
		}
	}
	private static Component execCreateChild0(
	CreateInfo ci, Component parent, ComponentInfo childInfo)
	throws IOException {
		final Composer composer = childInfo.getComposer(ci.page);
		final ComposerExt composerExt =
			composer instanceof ComposerExt ? (ComposerExt)composer: null;
		Component child = null;
		try {
			if (composerExt != null) {
				childInfo = composerExt.doBeforeCompose(ci.page, parent, childInfo);
				if (childInfo == null)
					return null;
			}

			child = ci.uf.newComponent(ci.page, parent, childInfo);

			final boolean bNative = childInfo instanceof NativeInfo;
			if (bNative)
				setProlog(ci, child, (NativeInfo)childInfo);

			if (composerExt != null)
				composerExt.doBeforeComposeChildren(child);

			execCreate(ci, childInfo, child); //recursive

			if (bNative)
				setEpilog(ci, child, (NativeInfo)childInfo);

			if (child instanceof AfterCompose)
				((AfterCompose)child).afterCompose();
			if (composer != null)
				composer.doAfterCompose(child);

			ComponentsCtrl.applyForward(child, childInfo.getForward());
				//applies the forward condition
				//1) we did it after all child created, so it may reference
				//to it child (thought rarely happens)
				//2) we did it after afterCompose, so what specified
				//here has higher priority than class defined by app dev

			if (Events.isListened(child, Events.ON_CREATE, false))
				Events.postEvent(
					new CreateEvent(Events.ON_CREATE, child, ci.exec.getArg()));

			return child;
		} catch (Throwable ex) {
			boolean ignore = false;
			if (composerExt != null) {
				try {
					ignore = composerExt.doCatch(ex);
				} catch (Throwable t) {
					log.error("Failed to invoke doCatch for "+childInfo, t);
				}
			}
			if (!ignore)
				throw UiException.Aide.wrap(ex);

			return child != null && child.getPage() != null ? child: null;
				//return child only if attached successfully
		} finally {
			if (composerExt != null) {
				try {
					composerExt.doFinally();
				} catch (Throwable ex) {
					throw UiException.Aide.wrap(ex);
				}
			}
		}
	}
	/** Executes a non-component object, such as ZScript, AttributesInfo...
	 */
	private static final void execNonComponent(
	CreateInfo ci, Component comp, Object meta) {
		final Page page = ci.page;
		if (meta instanceof ZScript) {
			final ZScript zscript = (ZScript)meta;
			if (zscript.isDeferred()) {
				((PageCtrl)page).addDeferredZScript(comp, zscript);
					//isEffective is handled later
			} else if (isEffective(zscript, page, comp)) {
				final Map backup = new HashMap();
				final Namespace ns = comp != null ?
					Namespaces.beforeInterpret(backup, comp, false):
					Namespaces.beforeInterpret(backup, page, false);
				try {
					page.interpret(zscript.getLanguage(),
						zscript.getContent(page, comp), ns);
				} finally {
					Namespaces.afterInterpret(backup, ns, false);
				}
			}
		} else if (meta instanceof AttributesInfo) {
			final AttributesInfo attrs = (AttributesInfo)meta;
			if (comp != null) attrs.apply(comp); //it handles isEffective
			else attrs.apply(page);
		} else if (meta instanceof VariablesInfo) {
			final VariablesInfo vars = (VariablesInfo)meta;
			if (comp != null) vars.apply(comp); //it handles isEffective
			else vars.apply(page);
		} else {
			throw new IllegalStateException("Unknown metainfo: "+meta);
		}
	}
	private static final boolean isEffective(Condition cond,
	Page page, Component comp) {
		return comp != null ? cond.isEffective(comp): cond.isEffective(page);
	}

	public Component[] createComponents(Execution exec,
	PageDefinition pagedef, Page page, Component parent, Map arg) {
		if (pagedef == null)
			throw new IllegalArgumentException("pagedef");
		if (parent != null) {
			if (parent.getPage() != null)
				page = parent.getPage();
		} else if (page != null) {
			parent = ((PageCtrl)page).getDefaultParent();
		}
		if (page == null)
			page = getCurrentPage(exec);

		final ExecutionCtrl execCtrl = (ExecutionCtrl)exec;
		if (!execCtrl.isActivated())
			throw new IllegalStateException("Not activated yet");

		final Page old = execCtrl.getCurrentPage();
		final PageDefinition olddef = execCtrl.getCurrentPageDefinition();
		if (page != null && page != old)
			execCtrl.setCurrentPage(page);
		execCtrl.setCurrentPageDefinition(pagedef);
		exec.pushArg(arg != null ? arg: Collections.EMPTY_MAP);

		//Note: we add taglib, stylesheets and var-resolvers to the page
		//it might cause name pollution but we got no choice since they
		//are used as long as components created by this method are alive
		if (page != null)
			pagedef.initXelContext(page);

		final Initiators inits = Initiators.doInit(pagedef, page);
		try {
			final Component[] comps = execCreate(
				new CreateInfo(
					((WebAppCtrl)exec.getDesktop().getWebApp()).getUiFactory(),
					exec, page),
				pagedef, parent);
			inits.doAfterCompose(page, comps);
			return comps;
		} catch (Throwable ex) {
			inits.doCatch(ex);
			throw UiException.Aide.wrap(ex);
		} finally {
			exec.popArg();
			execCtrl.setCurrentPage(old); //restore it
			execCtrl.setCurrentPageDefinition(olddef); //restore it

			inits.doFinally();
		}
	}

	public void sendRedirect(String uri, String target) {
		if (uri != null && uri.length() == 0)
			uri = null;
		final UiVisualizer uv = getCurrentVisualizer();
		uv.setAbortingReason(
			new AbortBySendRedirect(
				uri != null ? uv.getExecution().encodeURL(uri): "", target));
	}
	public void setAbortingReason(AbortingReason aborting) {
		final UiVisualizer uv = getCurrentVisualizer();
		uv.setAbortingReason(aborting);
	}

	//-- Recovering desktop --//
	public void execRecover(Execution exec, FailoverManager failover) {
		final Desktop desktop = exec.getDesktop();
		final Session sess = desktop.getSession();

		doActivate(exec, null, true); //it must not return null
		try {
			failover.recover(sess, exec, desktop);
		} finally {
			doDeactivate(exec);
		}
	}

	//-- Asynchronous updates --//
	public void execUpdate(Execution exec, List requests, Writer out)
	throws IOException {
		execUpdate(exec, requests, null, out);
	}
	public Collection execUpdate(Execution exec, List requests,
	String reqId, Writer out) throws IOException {
		if (requests == null)
			throw new IllegalArgumentException("null requests");
		assert D.OFF || ExecutionsCtrl.getCurrentCtrl() == null:
			"Impossible to re-activate for update: old="+ExecutionsCtrl.getCurrentCtrl()+", new="+exec+", reqs="+requests;

		final UiVisualizer uv = doActivate(exec, requests, false);
		if (uv == null)
			return null; //done (request is added to the exec currently activated)

		final Desktop desktop = exec.getDesktop();
		final Configuration config = desktop.getWebApp().getConfiguration();
		final Monitor monitor = config.getMonitor();
		if (monitor != null) {
			try {
				monitor.beforeUpdate(desktop, requests);
			} catch (Throwable ex) {
				log.error(ex);
			}
		}

		Collection doneReqIds = null; //request IDs that have been processed
		boolean cleaned = false;
		try {
			config.invokeExecutionInits(exec, null);
			final RequestQueue rque = ((DesktopCtrl)desktop).getRequestQueue();
			if (reqId != null) rque.addRequestId(reqId);

			final List errs = new LinkedList();
			final long tmexpired =
				System.currentTimeMillis() + config.getMaxProcessTime();
				//Tom Yeh: 20060120
				//Don't process all requests if this thread has processed
				//a while. Thus, user could see the response sooner.
			for (AuRequest request; System.currentTimeMillis() < tmexpired
			&& (request = rque.nextRequest()) != null;) {
				//Cycle 1: Process one request
				//Don't process more such that requests will be queued
				//adn we have the chance to optimize them
				try {
					process(exec, request, !errs.isEmpty());
				} catch (ComponentNotFoundException ex) {
					//possible because the previous might remove some comp
					//so ignore it
//					if (log.finable()) log.fine("Component not found: "+request);
				} catch (Throwable ex) {
					handleError(ex, uv, errs);
					//we don't skip request to avoid mis-match between c/s
				}

				//Cycle 2: Process any pending events posted by components
				Event event = nextEvent(uv);
				do {
					for (; event != null; event = nextEvent(uv)) {
						try {
							process(desktop, event);
						} catch (Throwable ex) {
							handleError(ex, uv, errs);
							break; //skip the rest of events! 
						}
					}

					resumeAll(desktop, uv, errs);
				} while ((event = nextEvent(uv)) != null);
			}

			//Cycle 2a: Handle aborting reason
			final AbortingReason abrn = uv.getAbortingReason();
			if (abrn != null)
				abrn.execute(); //always execute even if !isAborting

			//Cycle 3: Generate output
			List responses;
			try {
				//Note: we have to call visualizeErrors before uv.getResponses,
				//since it might create/update components
				if (!errs.isEmpty())
					visualizeErrors(exec, uv, errs);

				responses = uv.getResponses();
			} catch (Throwable ex) {
				responses = new LinkedList();
				responses.add(new AuAlert(Exceptions.getMessage(ex)));

				log.error(ex);
			}

			if (rque.endWithRequest())
				responses.add(new AuEcho(desktop));
			else
				doneReqIds = rque.clearRequestIds();

			responseSequenceId(desktop, out);
			response(responses, out);

//			if (log.debugable())
//				if (responses.size() < 5 || log.finerable()) log.finer("Responses: "+responses);
//				else log.debug("Responses: "+responses.subList(0, 5)+"...");

			cleaned = true;
			config.invokeExecutionCleanups(exec, null, errs);

			out.flush();
				//flush before deactivating to make sure it has been sent
		} catch (Throwable ex) {
			if (!cleaned) {
				cleaned = true;
				final List errs = new LinkedList();
				errs.add(ex);
				config.invokeExecutionCleanups(exec, null, errs);
				ex = errs.isEmpty() ? null: (Throwable)errs.get(0);
			}

			if (ex != null) {
				if (ex instanceof IOException) throw (IOException)ex;
				throw UiException.Aide.wrap(ex);
			}
		} finally {
			if (!cleaned) config.invokeExecutionCleanups(exec, null, null);