PageTrackingRequestCycleListener.java

package be.selckin.swu.debug;

import org.apache.wicket.MetaDataKey;
import org.apache.wicket.core.request.handler.IPageRequestHandler;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.component.IRequestablePage;
import org.apache.wicket.request.cycle.AbstractRequestCycleListener;
import org.apache.wicket.request.cycle.RequestCycle;

import java.lang.Boolean;
import java.lang.Exception;
import java.lang.Override;

public class PageTrackingRequestCycleListener extends AbstractRequestCycleListener {

    public static final MetaDataKey<IRequestablePage> REQUESTED_PAGE = new MetaDataKey<IRequestablePage>() {
    };

    public static final MetaDataKey<IRequestablePage> RESPONSE_PAGE = new MetaDataKey<IRequestablePage>() {
    };

    public static final MetaDataKey<Boolean> HAD_REQUEST = new MetaDataKey<Boolean>() {
    };

    @Override
    public void onRequestHandlerScheduled(RequestCycle cycle, IRequestHandler handler) {
        super.onRequestHandlerScheduled(cycle, handler);

        checkForPage(cycle, handler);
    }

    @Override
    public void onRequestHandlerResolved(RequestCycle cycle, IRequestHandler handler) {
        super.onRequestHandlerResolved(cycle, handler);

        checkForPage(cycle, handler);
    }

    @Override
    public void onExceptionRequestHandlerResolved(RequestCycle cycle, IRequestHandler handler,
                                                  Exception exception) {
        super.onExceptionRequestHandlerResolved(cycle, handler, exception);

        checkForPage(cycle, handler);
    }

    private void checkForPage(RequestCycle cycle, IRequestHandler handler) {
        if (handler instanceof IPageRequestHandler) {
            IPageRequestHandler pageRequestHandler = (IPageRequestHandler) handler;
            if (pageRequestHandler.isPageInstanceCreated()) {
                IRequestablePage page = pageRequestHandler.getPage();
                if (cycle.getMetaData(HAD_REQUEST) == null) {
                    cycle.setMetaData(REQUESTED_PAGE, page);
                    cycle.setMetaData(RESPONSE_PAGE, page);
                    cycle.setMetaData(HAD_REQUEST, true);
                } else {
                    cycle.setMetaData(RESPONSE_PAGE, page);
                }
            }
        }
    }
}