A StatelessAjaxFallbackLink

import static org.apache.wicket.protocol.http.request.WebRequestCodingStrategy.BOOKMARKABLE_PAGE_PARAMETER_NAME;

import org.apache.wicket.Page;
import org.apache.wicket.ajax.AjaxEventBehavior;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.IAjaxCallDecorator;
import org.apache.wicket.ajax.calldecorator.CancelEventIfNoAjaxDecorator;
import org.apache.wicket.ajax.markup.html.AjaxFallbackLink;
import org.apache.wicket.ajax.markup.html.IAjaxLink;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.html.link.Link;
import org.apache.wicket.model.IModel;

/**
 * Just like {@link AjaxFallbackLink}, but stateless.
 * 
 */
public abstract class StatelessAjaxFallbackLink<T> extends Link<T> implements
        IAjaxLink {
    private static final long serialVersionUID = -133600842398684777L;

    public StatelessAjaxFallbackLink(final String id) {
        this(id, null);
    }

    public StatelessAjaxFallbackLink(final String id, final IModel<T> model) {
        super(id, model);

        add(new AjaxEventBehavior("onclick") {
            private static final long serialVersionUID = 1L;

            @Override
            protected IAjaxCallDecorator getAjaxCallDecorator() {
                return new CancelEventIfNoAjaxDecorator(
                        StatelessAjaxFallbackLink.this.getAjaxCallDecorator());
            }

            @Override
            public final CharSequence getCallbackUrl(
                    final boolean onlyTargetActivePage) {
                final CharSequence callbackUrl = super.getCallbackUrl(false);

                return decorateCallbackUrl(callbackUrl);
            }

            @Override
            @SuppressWarnings("synthetic-access")
            protected void onComponentTag(final ComponentTag tag) {
                // only render handler if link is enabled
                if (isLinkEnabled()) {
                    super.onComponentTag(tag);
                }
            }

            @Override
            protected void onEvent(final AjaxRequestTarget target) {
                onClick(target);
            }
        });
    }

    protected final CharSequence decorateCallbackUrl(
            final CharSequence callbackUrl) {
        final Page page = getPage();
        final Class<? extends Page> pageCls = page.getClass();
        final String pageClsName = pageCls.getName();
        final StringBuilder buf = new StringBuilder();

        buf.append(callbackUrl);
        buf.append('&');
        buf.append(BOOKMARKABLE_PAGE_PARAMETER_NAME);
        buf.append("=");
        buf.append(PATH_SEPARATOR);
        buf.append(pageClsName);

        return buf; 
    }

    /**
     * 
     * @return call decorator to use or null if none
     */
    protected IAjaxCallDecorator getAjaxCallDecorator() {
        return null;
    }

    /**
     * Hints that this component is stateless.
     * 
     * @return always {@literal true}
     * @see Link#getStatelessHint()
     */
    @Override
    protected boolean getStatelessHint() {
        return true;
    }

    /**
     * @see Link#onClick()
     */
    @Override
    public final void onClick() {
        onClick(null);
    }

    /**
     * Callback for the onClick event. If ajax failed and this event was
     * generated via a normal link the target argument will be null
     * 
     * @param target
     *            ajax target if this linked was invoked using ajax, null
     *            otherwise
     */
    public abstract void onClick(final AjaxRequestTarget target);
}

package com.jolira.stateless;

import java.util.Map;

import org.apache.wicket.Component;
import org.apache.wicket.IPageFactory;
import org.apache.wicket.IRequestTarget;
import org.apache.wicket.Page;
import org.apache.wicket.PageParameters;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.RequestListenerInterface;
import org.apache.wicket.Session;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.request.IRequestCodingStrategy;
import org.apache.wicket.request.IRequestCycleProcessor;
import org.apache.wicket.request.RequestParameters;
import org.apache.wicket.request.target.component.listener.BehaviorRequestTarget;
import org.apache.wicket.settings.ISessionSettings;
import org.apache.wicket.util.string.Strings;

/**
 * Application object for your web application. If you want to run this
 * application without deploying, run the Start class.
 * 
 * @see com.jolira.stateless.Start#main(String[])
 */
public class WicketApplication extends WebApplication {
    /**
     * @see org.apache.wicket.Application#getHomePage()
     */
    @Override
    public Class<HomePage> getHomePage() {
        return HomePage.class;
    }

    @SuppressWarnings("unchecked")
    private Class<? extends Page> getPageClass(final Session session,
            final String clsName) {
        try {
            return (Class<? extends Page>) session.getClassResolver()
                    .resolveClass(clsName);
        } catch (final ClassNotFoundException e) {
            throw new WicketRuntimeException(
                    "Unable to load Bookmarkable Page", e);
        }
    }

    // lots of irrelevant code omitted .... }
    private <C extends Page> Page newPage(final Class<C> pageClass,
            final RequestCycle cycle, final PageParameters pageParameters) {
        final ISessionSettings settings = getSessionSettings();
        final IPageFactory pageFactory = settings.getPageFactory();

        final Map<String, String[]> requestMap = cycle.getRequest()
                .getParameterMap();
        final Map<String, String[]> reqParams = pageParameters
                .toRequestParameters();

        requestMap.putAll(reqParams);

        return pageFactory.newPage(pageClass, pageParameters);
    }

    /**
     * Install a new request processor to handle requests generated by any
     * {@link StatelessAjaxFallbackLink}.
     * 
     * @see WebApplication#newRequestCycleProcessor()
     */
    @Override
    protected IRequestCycleProcessor newRequestCycleProcessor() {
        final IRequestCycleProcessor processor = super
                .newRequestCycleProcessor();

        return new IRequestCycleProcessor() {
            public IRequestCodingStrategy getRequestCodingStrategy() {
                return processor.getRequestCodingStrategy();
            }

            public void processEvents(final RequestCycle requestCycle) {
                processor.processEvents(requestCycle);
            }

            public IRequestTarget resolve(final RequestCycle requestCycle,
                    final RequestParameters requestParameters) {
                return WicketApplication.this.resolve(processor, requestCycle,
                        requestParameters);
            }

            public void respond(final RequestCycle requestCycle) {
                processor.respond(requestCycle);
            }

            public void respond(final RuntimeException e,
                    final RequestCycle requestCycle) {
                processor.respond(e, requestCycle);
            }
        };
    }

    protected IRequestTarget resolve(final IRequestCycleProcessor processor,
            final RequestCycle cycle, final RequestParameters requestParameters) {
        final RequestListenerInterface iface = requestParameters.getInterface();
        final String behaviorId = requestParameters.getBehaviorId();
        final String pageName = requestParameters.getBookmarkablePageClass();

        if (iface == null || behaviorId == null || pageName == null) {
            return processor.resolve(cycle, requestParameters);
        }

        final Map<String, ?> _params = requestParameters.getParameters();
        final PageParameters params = new PageParameters(_params);
        final Session session = cycle.getSession();
        final Class<? extends Page> pageClass = getPageClass(session, pageName);
        final Page page = newPage(pageClass, cycle, params);
        final String componentPath = requestParameters.getComponentPath();
        final String pageRelativeComponentPath = Strings
                .afterFirstPathComponent(componentPath,
                        Component.PATH_SEPARATOR);
        final Component component = page.get(pageRelativeComponentPath);

        // See {@link
        // BookmarkableListenerInterfaceRequestTarget#processEvents(RequestCycle)}
        // We make have to try to look for the component twice, if we hit the
        // same condition.
        if (component == null) {
            throw new WicketRuntimeException(
                    "unable to find component with path "
                            + pageRelativeComponentPath
                            + " on stateless page "
                            + page
                            + " it could be that the component is inside a repeater make your component return false in getStatelessHint()");
        }

        final String interfaceName = requestParameters.getInterfaceName();
        final RequestListenerInterface listenerInterface = RequestListenerInterface
                .forName(interfaceName);

        if (listenerInterface == null) {
            throw new WicketRuntimeException(
                    "unable to find listener interface " + interfaceName);
        }

        return new BehaviorRequestTarget(page, component, listenerInterface,
                requestParameters);
    }

}