Wicket 中的无状态模态对话框答案

【问题标题】：Stateless ModalDialog in WicketWicket 中的无状态模态对话框
【发布时间】：2021-04-14 08:07:39
【问题描述】：

如何使用 Wicket 创建无状态的ModalDialog？

我尝试了以下代码，但它导致错误。删除 getStatelessHint() 覆盖时不会发生错误，但这会使其成为有状态的。如果不可能，是否可以使用已弃用的ModalWindow？

HTML：

<!DOCTYPE html>
<html>
<head>
    <style>
        .modal-dialog { border-radius: 5px; }
        .modal-dialog .modal-dialog-content { display: flex; flex-direction: column; }
        .modal-dialog-overlay.current-focus-trap .modal-dialog-content { resize: both; }
        .modal-dialog .modal-dialog-form { margin: 0; padding: 0; overflow: hidden; flex: 1; display: flex; flex-direction: column; }
        .modal-dialog .modal-dialog-header { border-radius: 5px 5px 0px 0px; background: #ffb158; margin: 0; padding-top: 4px; text-align: center; }
        .modal-dialog .modal-dialog-body { flex: 1; overflow-y: auto; padding: 20px; }
        .modal-dialog .modal-dialog-footer { padding: 5px; }
    </style>
</head>
<body>
    <a wicket:id="openModalLink">Open modal</a>

    <div id="window" wicket:id="window"></div>

    <wicket:fragment wicket:id="modalContentFragment">
        <h1>Modal Dialog</h1>
        <a wicket:id="closeModalLink">Close modal</a>
    </wicket:fragment>
</body>
</html>

Java：

package org.example.modaltest;

import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.markup.html.AjaxLink;
import org.apache.wicket.extensions.ajax.markup.html.modal.ModalDialog;
import org.apache.wicket.extensions.ajax.markup.html.modal.theme.DefaultTheme;
import org.apache.wicket.markup.html.GenericWebPage;
import org.apache.wicket.markup.html.panel.Fragment;

public class ModalPage extends GenericWebPage<Void> {
    public ModalPage() {
        ModalDialog window = new ModalDialog("window");
        window.add(new DefaultTheme());
        window.setMarkupId("window");
        window.setOutputMarkupId(true);
        add(window);

        Fragment modalContentFragment = new Fragment(ModalDialog.CONTENT_ID, "modalContentFragment", this);
        window.setContent(modalContentFragment);
        modalContentFragment.setOutputMarkupId(true);

        AjaxLink<Void> closeModalLink = new AjaxLink<Void>("closeModalLink") {
            @Override
            public void onClick(AjaxRequestTarget target) {
                target.add(window);
                ModalDialog window1 = (ModalDialog) findPage().get("window");
                window1.close(target);
            }

            @Override
            protected boolean getStatelessHint() {
                return true;
            }
        };
        closeModalLink.setOutputMarkupId(true);
        modalContentFragment.add(closeModalLink);

        AjaxLink<Void> openModalLink = new AjaxLink<Void>("openModalLink") {
            @Override
            public void onClick(AjaxRequestTarget target) {
                ModalDialog window1 = (ModalDialog) findPage().get("window");
                window1.open(target);
            }

            @Override
            protected boolean getStatelessHint() {
                return true;
            }
        };
        add(openModalLink);
    }
}

浏览器错误：

访问被拒绝。您无权访问您请求的页面。返回首页

Java 异常：

16:34:16.382 [http-nio-8080-exec-4] WARN  o.a.w.c.r.h.ListenerRequestHandler - behavior not enabled; ignore call. Behavior org.apache.wicket.ajax.markup.html.AjaxLink$1@5a149041 at component [AjaxLink [Component id = closeModalLink]]
16:34:16.386 [http-nio-8080-exec-4] WARN  RequestCycleExtra - ********************************
16:34:16.390 [http-nio-8080-exec-4] WARN  RequestCycleExtra - Handling the following exception
org.apache.wicket.core.request.handler.ListenerInvocationNotAllowedException: Behavior rejected interface invocation. Component: [AjaxLink [Component id = closeModalLink]] Behavior: org.apache.wicket.ajax.markup.html.AjaxLink$1@5a149041
    at org.apache.wicket.core.request.handler.ListenerRequestHandler.invoke(ListenerRequestHandler.java:276)
    at org.apache.wicket.core.request.handler.ListenerRequestHandler.invokeListener(ListenerRequestHandler.java:222)
    at org.apache.wicket.core.request.handler.ListenerRequestHandler.respond(ListenerRequestHandler.java:208)
    at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:902)
    at org.apache.wicket.request.RequestHandlerExecutor.execute(RequestHandlerExecutor.java:63)
    at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:283)
    at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:254)
    at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:276)
    at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:207)
    at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:306)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:651)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:407)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:754)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1376)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:834)
16:34:16.390 [http-nio-8080-exec-4] WARN  RequestCycleExtra - ********************************

【问题讨论】：

标签： java wicket stateless

【解决方案1】：

这是@svenmeier 试图解释的内容：

使用页面参数存储对话框状态（打开/关闭）
如果状态为opened，则在页面创建时预先打开对话框，以便在以下请求中可以访问其中的任何组件/行为
在open链接中添加一个额外的参数来设置状态

public class ModalPage extends GenericWebPage<Void> {
    public ModalPage(PageParameters parameters) {
        super(parameters);   // 1

        ModalDialog window = new ModalDialog("window");
        window.add(new DefaultTheme());
        window.setMarkupId("window");
        window.setOutputMarkupId(true);
        add(window);

        if (!parameters.get("mdOpened").isNull()) {  // 2
            window.open(null);
        }

        Fragment modalContentFragment = new Fragment(ModalDialog.CONTENT_ID, "modalContentFragment", this);
        window.setContent(modalContentFragment);
        modalContentFragment.setOutputMarkupId(true);

        AjaxLink<Void> closeModalLink = new AjaxLink<Void>("closeModalLink") {
            @Override
            public void onClick(AjaxRequestTarget target) {
                target.add(window);
                ModalDialog window1 = (ModalDialog) findPage().get("window");
                window1.close(target);
            }

            @Override
            protected boolean getStatelessHint() {
                return true;
            }
        };
        closeModalLink.setOutputMarkupId(true);
        modalContentFragment.add(closeModalLink);

        AjaxLink<Void> openModalLink = new AjaxLink<Void>("openModalLink") {
            @Override
            public void onClick(AjaxRequestTarget target) {
                ModalDialog window1 = (ModalDialog) findPage().get("window");
                window1.open(target);
            }

            @Override
            protected boolean getStatelessHint() {
                return true;
            }

            // 3
            @Override
            public void updateAjaxAttributes(AjaxRequestAttributes attributes) {
                attributes.getExtraParameters().put("mdOpened", "true");
            }
        };
        add(openModalLink);
    }
}

【讨论】：

【解决方案2】：

问题如下：无状态链接为每个请求创建一个新页面。该新页面不知道模态对话框先前已打开。因此，对嵌套的 closeModalLink 的请求被拒绝，因为它当前不可见。

您必须通过请求 URL 传输有关打开对话框的信息。例如。您的 closeModalLink 可以通过 #updateAjaxAttributes() 向其请求添加一个参数，该参数在创建 new 页面时进行检查，并在请求时自动打开对话框。

【讨论】：

ModalDialog 中的每个组件操作在无状态时似乎都会失败，即使没有请求关闭它也是如此。因此，如果我将AjaxEventBehavior 添加到侦听单击事件的 ModalDialog 中，那么即使没有单击 closeLink，它也会在每次单击时失败。因此，如果我添加一个 AjaxLink，它会在到达其 onClick() 方法之前失败。