Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.apache.isis.viewer.wicket.ui.components.widgets.linkandlabel; import org.apache.wicket.Application; import org.apache.wicket.RestartResponseException; import org.apache.wicket.ajax.AjaxRequestTarget; import org.apache.wicket.ajax.IAjaxIndicatorAware; import org.apache.wicket.ajax.attributes.AjaxRequestAttributes; import org.apache.wicket.ajax.markup.html.AjaxLink; import org.apache.wicket.extensions.ajax.markup.html.AjaxIndicatorAppender; import org.apache.wicket.markup.ComponentTag; import org.apache.wicket.request.IRequestHandler; import org.apache.wicket.request.handler.resource.ResourceStreamRequestHandler; import org.apache.wicket.util.time.Duration; import org.apache.isis.applib.annotation.SemanticsOf; import org.apache.isis.core.metamodel.adapter.ObjectAdapter; import org.apache.isis.core.metamodel.adapter.version.ConcurrencyException; import org.apache.isis.core.metamodel.spec.feature.ObjectAction; import org.apache.isis.core.metamodel.specloader.SpecificationLoader; import org.apache.isis.core.runtime.system.context.IsisContext; import org.apache.isis.viewer.wicket.model.isis.WicketViewerSettings; import org.apache.isis.viewer.wicket.model.isis.WicketViewerSettingsAccessor; import org.apache.isis.viewer.wicket.model.models.ActionModel; import org.apache.isis.viewer.wicket.ui.pages.entity.EntityPage; import org.apache.isis.viewer.wicket.ui.panels.PanelUtil; import de.agilecoders.wicket.core.markup.html.bootstrap.button.Buttons; public abstract class ActionLink extends AjaxLink<ObjectAdapter> implements IAjaxIndicatorAware { private static final long serialVersionUID = 1L; private final AjaxIndicatorAppender indicatorAppenderIfAny; final AjaxDeferredBehaviour ajaxDeferredBehaviourIfAny; public ActionLink(String id, ActionModel model) { this(id, model, null); } ActionLink(String id, ActionModel model, ObjectAction action) { super(id, model); final boolean useIndicatorForNoArgAction = getSettings().isUseIndicatorForNoArgAction(); this.indicatorAppenderIfAny = useIndicatorForNoArgAction ? new AjaxIndicatorAppender() : null; if (this.indicatorAppenderIfAny != null) { this.add(this.indicatorAppenderIfAny); } // trivial optimization; also store the objectAction if it is available (saves looking it up) objectAction = action; // this returns non-null if the action is no-arg and returns a URL or a Blob or a Clob. // Otherwise can use default handling // TODO: the method looks at the actual compile-time return type; // TODO: cannot see a way to check at runtime what is returned. // TODO: see https://issues.apache.org/jira/browse/ISIS-1264 for further detail. ajaxDeferredBehaviourIfAny = determineDeferredBehaviour(); if (ajaxDeferredBehaviourIfAny != null) { this.add(ajaxDeferredBehaviourIfAny); } } @Override public void onClick(AjaxRequestTarget target) { if (ajaxDeferredBehaviourIfAny != null) { ajaxDeferredBehaviourIfAny.initiate(target); return; } doOnClick(target); } protected abstract void doOnClick(AjaxRequestTarget target); ActionModel getActionModel() { return (ActionModel) getModel(); } private transient ObjectAction objectAction; public ObjectAction getObjectAction() { return objectAction != null ? objectAction : (objectAction = getActionModel().getActionMemento().getAction(getSpecificationLoader())); } @Override protected void updateAjaxAttributes(AjaxRequestAttributes attributes) { super.updateAjaxAttributes(attributes); if (getSettings().isPreventDoubleClickForNoArgAction()) { PanelUtil.disableBeforeReenableOnComplete(attributes, this); } // allow the event to bubble so the menu is hidden after click on an item attributes.setEventPropagation(AjaxRequestAttributes.EventPropagation.BUBBLE); } public String getReasonDisabledIfAny() { return getActionModel().getReasonDisabledIfAny(); } @Override public boolean isVisible() { return getActionModel().isVisible(); } @Override public boolean isEnabled() { try { final String reasonDisabledIfAny = getReasonDisabledIfAny(); return reasonDisabledIfAny == null; } catch (ConcurrencyException ex) { // // this has to be here because it's the first method called by an action link listener // on a potentially stale model. // // there is similar code for editing properties (ScalarPanelAbstract2) // IsisContext.getSessionFactory().getCurrentSession().getAuthenticationSession().getMessageBroker() .addMessage(ex.getMessage()); throw new RestartResponseException(new EntityPage(getActionModel().getTargetAdapter())); } } @Override protected void onComponentTag(ComponentTag tag) { super.onComponentTag(tag); Buttons.fixDisabledState(this, tag); } public String getAjaxIndicatorMarkupId() { return this.indicatorAppenderIfAny != null ? this.indicatorAppenderIfAny.getMarkupId() : null; } protected WicketViewerSettings getSettings() { return ((WicketViewerSettingsAccessor) Application.get()).getSettings(); } protected SpecificationLoader getSpecificationLoader() { return IsisContext.getSessionFactory().getSpecificationLoader(); } AjaxDeferredBehaviour determineDeferredBehaviour() { final ObjectAction action = getObjectAction(); final ActionModel actionModel = this.getActionModel(); // TODO: should unify with ActionResultResponseType (as used in ActionParametersPanel) if (isNoArgReturnTypeRedirect(action)) { /** * adapted from: * * @see https://cwiki.apache.org/confluence/display/WICKET/AJAX+update+and+file+download+in+one+blow */ return new AjaxDeferredBehaviour(AjaxDeferredBehaviour.OpenUrlStrategy.NEW_WINDOW) { private static final long serialVersionUID = 1L; @Override protected IRequestHandler getRequestHandler() { ObjectAdapter resultAdapter = actionModel.execute(); final Object value = resultAdapter.getObject(); return ActionModel.redirectHandler(value); } }; } if (isNoArgReturnTypeDownload(action)) { /** * adapted from: * * @see https://cwiki.apache.org/confluence/display/WICKET/AJAX+update+and+file+download+in+one+blow */ return new AjaxDeferredBehaviour(AjaxDeferredBehaviour.OpenUrlStrategy.SAME_WINDOW) { private static final long serialVersionUID = 1L; @Override protected IRequestHandler getRequestHandler() { final ObjectAdapter resultAdapter = actionModel.execute(); final Object value = resultAdapter.getObject(); final IRequestHandler handler = ActionModel.downloadHandler(value); //XXX ISIS-1619, prevent clients from caching the response content return isNonIdempotent(actionModel) ? enforceNoCacheOnClientSide(handler) : handler; } }; } return null; } // TODO: should unify with ActionResultResponseType (as used in ActionParametersPanel) private static boolean isNoArgReturnTypeRedirect(final ObjectAction action) { return action.getParameterCount() == 0 && action.getReturnType() != null && action.getReturnType().getCorrespondingClass() == java.net.URL.class; } // TODO: should unify with ActionResultResponseType (as used in ActionParametersPanel) private static boolean isNoArgReturnTypeDownload(final ObjectAction action) { return action.getParameterCount() == 0 && action.getReturnType() != null && (action.getReturnType().getCorrespondingClass() == org.apache.isis.applib.value.Blob.class || action.getReturnType() .getCorrespondingClass() == org.apache.isis.applib.value.Clob.class); } private static boolean isNonIdempotent(ActionModel actionModel) { final ObjectAction objectAction = actionModel.getActionMemento() .getAction(actionModel.getSpecificationLoader()); return ObjectAction.Util.isNonIdempotent(objectAction); } // -- CLIENT SIDE CACHING ASPECTS ... private static IRequestHandler enforceNoCacheOnClientSide(IRequestHandler downloadHandler) { if (downloadHandler == null) return downloadHandler; if (downloadHandler instanceof ResourceStreamRequestHandler) ((ResourceStreamRequestHandler) downloadHandler).setCacheDuration(Duration.seconds(0)); return downloadHandler; } // -- }