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.wicket.ajax; import java.util.List; import com.github.openjson.JSONArray; import com.github.openjson.JSONException; import com.github.openjson.JSONObject; import org.apache.wicket.Component; import org.apache.wicket.Page; import org.apache.wicket.WicketRuntimeException; import org.apache.wicket.ajax.attributes.AjaxAttributeName; import org.apache.wicket.ajax.attributes.AjaxRequestAttributes; import org.apache.wicket.ajax.attributes.AjaxRequestAttributes.Method; import org.apache.wicket.ajax.attributes.CallbackParameter; import org.apache.wicket.ajax.attributes.IAjaxCallListener; import org.apache.wicket.ajax.attributes.ThrottlingSettings; import org.apache.wicket.ajax.json.JSONFunction; import org.apache.wicket.ajax.json.JsonUtils; import org.apache.wicket.behavior.AbstractAjaxBehavior; import org.apache.wicket.markup.head.IHeaderResponse; import org.apache.wicket.markup.head.JavaScriptHeaderItem; import org.apache.wicket.markup.html.IComponentAwareHeaderContributor; import org.apache.wicket.protocol.http.WebApplication; import org.apache.wicket.request.Url; import org.apache.wicket.request.cycle.RequestCycle; import org.apache.wicket.request.resource.PackageResourceReference; import org.apache.wicket.request.resource.ResourceReference; import org.apache.wicket.resource.CoreLibrariesContributor; import org.apache.wicket.util.string.Strings; import org.apache.wicket.util.time.Duration; /** * The base class for Wicket's default AJAX implementation. * * @since 1.2 * * @author Igor Vaynberg (ivaynberg) * */ public abstract class AbstractDefaultAjaxBehavior extends AbstractAjaxBehavior { private static final long serialVersionUID = 1L; /** reference to the default indicator gif file. */ public static final ResourceReference INDICATOR = new PackageResourceReference( AbstractDefaultAjaxBehavior.class, "indicator.gif"); private static final String DYNAMIC_PARAMETER_FUNCTION_TEMPLATE = "function(attrs){%s}"; private static final String PRECONDITION_FUNCTION_TEMPLATE = "function(attrs){%s}"; private static final String COMPLETE_HANDLER_FUNCTION_TEMPLATE = "function(attrs, jqXHR, textStatus){%s}"; private static final String FAILURE_HANDLER_FUNCTION_TEMPLATE = "function(attrs, jqXHR, errorMessage, textStatus){%s}"; private static final String SUCCESS_HANDLER_FUNCTION_TEMPLATE = "function(attrs, jqXHR, data, textStatus){%s}"; private static final String AFTER_HANDLER_FUNCTION_TEMPLATE = "function(attrs){%s}"; private static final String BEFORE_SEND_HANDLER_FUNCTION_TEMPLATE = "function(attrs, jqXHR, settings){%s}"; private static final String BEFORE_HANDLER_FUNCTION_TEMPLATE = "function(attrs){%s}"; private static final String INIT_HANDLER_FUNCTION_TEMPLATE = "function(attrs){%s}"; private static final String DONE_HANDLER_FUNCTION_TEMPLATE = "function(attrs){%s}"; /** * Subclasses should call super.onBind() * * @see org.apache.wicket.behavior.AbstractAjaxBehavior#onBind() */ @Override protected void onBind() { final Component component = getComponent(); component.setOutputMarkupId(true); if (getStatelessHint(component)) { //generate behavior id component.getBehaviorId(this); } } /** * @see org.apache.wicket.behavior.AbstractAjaxBehavior#renderHead(Component, * org.apache.wicket.markup.head.IHeaderResponse) */ @Override public void renderHead(final Component component, final IHeaderResponse response) { super.renderHead(component, response); CoreLibrariesContributor.contributeAjax(component.getApplication(), response); RequestCycle requestCycle = component.getRequestCycle(); Url baseUrl = requestCycle.getUrlRenderer().getBaseUrl(); CharSequence ajaxBaseUrl = Strings.escapeMarkup(baseUrl.toString()); response.render(JavaScriptHeaderItem.forScript("Wicket.Ajax.baseUrl=\"" + ajaxBaseUrl + "\";", "wicket-ajax-base-url")); renderExtraHeaderContributors(component, response); } /** * Renders header contribution by IAjaxCallListener instances which additionally implement * IComponentAwareHeaderContributor interface. * * @param component * the component assigned to this behavior * @param response * the current header response */ private void renderExtraHeaderContributors(final Component component, final IHeaderResponse response) { AjaxRequestAttributes attributes = getAttributes(); List<IAjaxCallListener> ajaxCallListeners = attributes.getAjaxCallListeners(); for (IAjaxCallListener ajaxCallListener : ajaxCallListeners) { if (ajaxCallListener instanceof IComponentAwareHeaderContributor) { IComponentAwareHeaderContributor contributor = (IComponentAwareHeaderContributor) ajaxCallListener; contributor.renderHead(component, response); } } } /** * @return the Ajax settings for this behavior * @since 6.0 */ protected final AjaxRequestAttributes getAttributes() { AjaxRequestAttributes attributes = new AjaxRequestAttributes(); WebApplication application = (WebApplication) getComponent().getApplication(); AjaxRequestTargetListenerCollection ajaxRequestTargetListeners = application .getAjaxRequestTargetListeners(); for (AjaxRequestTarget.IListener listener : ajaxRequestTargetListeners) { listener.updateAjaxAttributes(this, attributes); } updateAjaxAttributes(attributes); return attributes; } /** * Gives a chance to the specializations to modify the attributes. * * @param attributes * @since 6.0 */ protected void updateAjaxAttributes(AjaxRequestAttributes attributes) { } /** * <pre> * { * u: 'editable-label?6-1.IBehaviorListener.0-text1-label', // url * m: 'POST', // method name. Default: 'GET' * c: 'label7', // component id (String) or window for page * e: 'click', // event name * sh: [], // list of success handlers * fh: [], // list of failure handlers * pre: [], // list of preconditions. If empty set default : Wicket.$(settings{c}) !== null * ep: {}, // extra parameters * async: true|false, // asynchronous XHR or not * ch: 'someName|d', // AjaxChannel * i: 'indicatorId', // indicator component id * ad: true, // allow default * } * </pre> * * @param component * the component with that behavior * @return the attributes as string in JSON format */ protected final CharSequence renderAjaxAttributes(final Component component) { AjaxRequestAttributes attributes = getAttributes(); return renderAjaxAttributes(component, attributes); } /** * * @param component * @param attributes * @return the attributes as string in JSON format */ protected final CharSequence renderAjaxAttributes(final Component component, AjaxRequestAttributes attributes) { JSONObject attributesJson = new JSONObject(); try { attributesJson.put(AjaxAttributeName.URL.jsonName(), getCallbackUrl()); Method method = attributes.getMethod(); if (Method.POST == method) { attributesJson.put(AjaxAttributeName.METHOD.jsonName(), method); } if (component instanceof Page == false) { String componentId = component.getMarkupId(); attributesJson.put(AjaxAttributeName.MARKUP_ID.jsonName(), componentId); } String formId = attributes.getFormId(); if (Strings.isEmpty(formId) == false) { attributesJson.put(AjaxAttributeName.FORM_ID.jsonName(), formId); } if (attributes.isMultipart()) { attributesJson.put(AjaxAttributeName.IS_MULTIPART.jsonName(), true); } String submittingComponentId = attributes.getSubmittingComponentName(); if (Strings.isEmpty(submittingComponentId) == false) { attributesJson.put(AjaxAttributeName.SUBMITTING_COMPONENT_NAME.jsonName(), submittingComponentId); } CharSequence childSelector = attributes.getChildSelector(); if (Strings.isEmpty(childSelector) == false) { attributesJson.put(AjaxAttributeName.CHILD_SELECTOR.jsonName(), childSelector); } if (attributes.isSerializeRecursively()) { attributesJson.put(AjaxAttributeName.SERIALIZE_RECURSIVELY.jsonName(), true); } String indicatorId = findIndicatorId(); if (Strings.isEmpty(indicatorId) == false) { attributesJson.put(AjaxAttributeName.INDICATOR_ID.jsonName(), indicatorId); } for (IAjaxCallListener ajaxCallListener : attributes.getAjaxCallListeners()) { if (ajaxCallListener != null) { CharSequence initHandler = ajaxCallListener.getInitHandler(component); appendListenerHandler(initHandler, attributesJson, AjaxAttributeName.INIT_HANDLER.jsonName(), INIT_HANDLER_FUNCTION_TEMPLATE); CharSequence beforeHandler = ajaxCallListener.getBeforeHandler(component); appendListenerHandler(beforeHandler, attributesJson, AjaxAttributeName.BEFORE_HANDLER.jsonName(), BEFORE_HANDLER_FUNCTION_TEMPLATE); CharSequence beforeSendHandler = ajaxCallListener.getBeforeSendHandler(component); appendListenerHandler(beforeSendHandler, attributesJson, AjaxAttributeName.BEFORE_SEND_HANDLER.jsonName(), BEFORE_SEND_HANDLER_FUNCTION_TEMPLATE); CharSequence afterHandler = ajaxCallListener.getAfterHandler(component); appendListenerHandler(afterHandler, attributesJson, AjaxAttributeName.AFTER_HANDLER.jsonName(), AFTER_HANDLER_FUNCTION_TEMPLATE); CharSequence successHandler = ajaxCallListener.getSuccessHandler(component); appendListenerHandler(successHandler, attributesJson, AjaxAttributeName.SUCCESS_HANDLER.jsonName(), SUCCESS_HANDLER_FUNCTION_TEMPLATE); CharSequence failureHandler = ajaxCallListener.getFailureHandler(component); appendListenerHandler(failureHandler, attributesJson, AjaxAttributeName.FAILURE_HANDLER.jsonName(), FAILURE_HANDLER_FUNCTION_TEMPLATE); CharSequence completeHandler = ajaxCallListener.getCompleteHandler(component); appendListenerHandler(completeHandler, attributesJson, AjaxAttributeName.COMPLETE_HANDLER.jsonName(), COMPLETE_HANDLER_FUNCTION_TEMPLATE); CharSequence precondition = ajaxCallListener.getPrecondition(component); appendListenerHandler(precondition, attributesJson, AjaxAttributeName.PRECONDITION.jsonName(), PRECONDITION_FUNCTION_TEMPLATE); CharSequence doneHandler = ajaxCallListener.getDoneHandler(component); appendListenerHandler(doneHandler, attributesJson, AjaxAttributeName.DONE_HANDLER.jsonName(), DONE_HANDLER_FUNCTION_TEMPLATE); } } JSONArray extraParameters = JsonUtils.asArray(attributes.getExtraParameters()); if (extraParameters.length() > 0) { attributesJson.put(AjaxAttributeName.EXTRA_PARAMETERS.jsonName(), extraParameters); } List<CharSequence> dynamicExtraParameters = attributes.getDynamicExtraParameters(); if (dynamicExtraParameters != null) { for (CharSequence dynamicExtraParameter : dynamicExtraParameters) { String func = String.format(DYNAMIC_PARAMETER_FUNCTION_TEMPLATE, dynamicExtraParameter); JSONFunction function = new JSONFunction(func); attributesJson.append(AjaxAttributeName.DYNAMIC_PARAMETER_FUNCTION.jsonName(), function); } } if (attributes.isAsynchronous() == false) { attributesJson.put(AjaxAttributeName.IS_ASYNC.jsonName(), false); } String[] eventNames = attributes.getEventNames(); if (eventNames.length == 1) { attributesJson.put(AjaxAttributeName.EVENT_NAME.jsonName(), eventNames[0]); } else { for (String eventName : eventNames) { attributesJson.append(AjaxAttributeName.EVENT_NAME.jsonName(), eventName); } } AjaxChannel channel = attributes.getChannel(); if (channel != null && channel.equals(AjaxChannel.DEFAULT) == false) { attributesJson.put(AjaxAttributeName.CHANNEL.jsonName(), channel); } if (attributes.isPreventDefault()) { attributesJson.put(AjaxAttributeName.IS_PREVENT_DEFAULT.jsonName(), true); } if (AjaxRequestAttributes.EventPropagation.STOP.equals(attributes.getEventPropagation())) { attributesJson.put(AjaxAttributeName.EVENT_PROPAGATION.jsonName(), "stop"); } else if (AjaxRequestAttributes.EventPropagation.STOP_IMMEDIATE .equals(attributes.getEventPropagation())) { attributesJson.put(AjaxAttributeName.EVENT_PROPAGATION.jsonName(), "stopImmediate"); } Duration requestTimeout = attributes.getRequestTimeout(); if (requestTimeout != null) { attributesJson.put(AjaxAttributeName.REQUEST_TIMEOUT.jsonName(), requestTimeout.getMilliseconds()); } boolean wicketAjaxResponse = attributes.isWicketAjaxResponse(); if (wicketAjaxResponse == false) { attributesJson.put(AjaxAttributeName.IS_WICKET_AJAX_RESPONSE.jsonName(), false); } String dataType = attributes.getDataType(); if (AjaxRequestAttributes.XML_DATA_TYPE.equals(dataType) == false) { attributesJson.put(AjaxAttributeName.DATATYPE.jsonName(), dataType); } ThrottlingSettings throttlingSettings = attributes.getThrottlingSettings(); if (throttlingSettings != null) { JSONObject throttlingSettingsJson = new JSONObject(); String throttleId = throttlingSettings.getId(); if (throttleId == null) { throttleId = component.getMarkupId(); } throttlingSettingsJson.put(AjaxAttributeName.THROTTLING_ID.jsonName(), throttleId); throttlingSettingsJson.put(AjaxAttributeName.THROTTLING_DELAY.jsonName(), throttlingSettings.getDelay().getMilliseconds()); if (throttlingSettings.getPostponeTimerOnUpdate()) { throttlingSettingsJson.put(AjaxAttributeName.THROTTLING_POSTPONE_ON_UPDATE.jsonName(), true); } attributesJson.put(AjaxAttributeName.THROTTLING.jsonName(), throttlingSettingsJson); } postprocessConfiguration(attributesJson, component); } catch (JSONException e) { throw new WicketRuntimeException(e); } String attributesAsJson = attributesJson.toString(); return attributesAsJson; } private void appendListenerHandler(final CharSequence handler, final JSONObject attributesJson, final String propertyName, final String functionTemplate) throws JSONException { if (Strings.isEmpty(handler) == false) { final JSONFunction function; if (handler instanceof JSONFunction) { function = (JSONFunction) handler; } else { String func = String.format(functionTemplate, handler); function = new JSONFunction(func); } attributesJson.append(propertyName, function); } } /** * Gives a chance to modify the JSON attributesJson that is going to be used as attributes for * the Ajax call. * * @param attributesJson * the JSON object created by #renderAjaxAttributes() * @param component * the component with the attached Ajax behavior * @throws JSONException * thrown if an error occurs while modifying {@literal attributesJson} argument */ protected void postprocessConfiguration(JSONObject attributesJson, Component component) throws JSONException { } /** * @return javascript that will generate an ajax GET request to this behavior with its assigned * component */ public CharSequence getCallbackScript() { return getCallbackScript(getComponent()); } /** * @param component * the component to use when generating the attributes * @return script that can be used to execute this Ajax behavior. */ // 'protected' because this method is intended to be called by other Behavior methods which // accept the component as parameter protected CharSequence getCallbackScript(final Component component) { CharSequence ajaxAttributes = renderAjaxAttributes(component); return "Wicket.Ajax.ajax(" + ajaxAttributes + ");"; } /** * Generates a javascript function that can take parameters and performs an AJAX call which * includes these parameters. The generated code looks like this: * * <pre> * function(param1, param2) { * var attrs = attrsJson; * var params = {'param1': param1, 'param2': param2}; * attrs.ep = jQuery.extend(attrs.ep, params); * Wicket.Ajax.ajax(attrs); * } * </pre> * * @param extraParameters * @return A function that can be used as a callback function in javascript */ public CharSequence getCallbackFunction(CallbackParameter... extraParameters) { StringBuilder sb = new StringBuilder(); sb.append("function ("); boolean first = true; for (CallbackParameter curExtraParameter : extraParameters) { if (curExtraParameter.getFunctionParameterName() != null) { if (!first) sb.append(','); else first = false; sb.append(curExtraParameter.getFunctionParameterName()); } } sb.append(") {\n"); sb.append(getCallbackFunctionBody(extraParameters)); sb.append("}\n"); return sb; } /** * Generates the body the {@linkplain #getCallbackFunction(CallbackParameter...) callback * function}. To embed this code directly into a piece of javascript, make sure any context * parameters are available as local variables, global variables or within the closure. * * @param extraParameters * @return The body of the {@linkplain #getCallbackFunction(CallbackParameter...) callback * function}. */ public CharSequence getCallbackFunctionBody(CallbackParameter... extraParameters) { AjaxRequestAttributes attributes = getAttributes(); attributes.setEventNames(); CharSequence attrsJson = renderAjaxAttributes(getComponent(), attributes); StringBuilder sb = new StringBuilder(); sb.append("var attrs = "); sb.append(attrsJson); sb.append(";\n"); JSONArray jsonArray = new JSONArray(); for (CallbackParameter curExtraParameter : extraParameters) { if (curExtraParameter.getAjaxParameterName() != null) { try { JSONObject object = new JSONObject(); object.put("name", curExtraParameter.getAjaxParameterName()); object.put("value", new JSONFunction(curExtraParameter.getAjaxParameterCode())); jsonArray.put(object); } catch (JSONException e) { throw new WicketRuntimeException(e); } } } sb.append("var params = ").append(jsonArray).append(";\n"); sb.append("attrs.").append(AjaxAttributeName.EXTRA_PARAMETERS).append(" = params.concat(attrs.") .append(AjaxAttributeName.EXTRA_PARAMETERS).append(" || []);\n"); sb.append("Wicket.Ajax.ajax(attrs);\n"); return sb; } /** * Finds the markup id of the indicator. The default search order is: component, behavior, * component's parent hierarchy. * * @return markup id or <code>null</code> if no indicator found */ protected String findIndicatorId() { if (getComponent() instanceof IAjaxIndicatorAware) { return ((IAjaxIndicatorAware) getComponent()).getAjaxIndicatorMarkupId(); } if (this instanceof IAjaxIndicatorAware) { return ((IAjaxIndicatorAware) this).getAjaxIndicatorMarkupId(); } Component parent = getComponent().getParent(); while (parent != null) { if (parent instanceof IAjaxIndicatorAware) { return ((IAjaxIndicatorAware) parent).getAjaxIndicatorMarkupId(); } parent = parent.getParent(); } return null; } @Override public final void onRequest() { WebApplication app = (WebApplication) getComponent().getApplication(); AjaxRequestTarget target = app.newAjaxRequestTarget(getComponent().getPage()); RequestCycle requestCycle = RequestCycle.get(); requestCycle.scheduleRequestHandlerAfterCurrent(target); respond(target); } /** * @param target * The AJAX target */ protected abstract void respond(AjaxRequestTarget target); }