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.markup.html.form; import org.apache.wicket.IRequestListener; import org.apache.wicket.markup.ComponentTag; import org.apache.wicket.model.IModel; /** * A link which can be used exactly like a Button to submit a Form. The onclick of the link will use * JavaScript to submit the form. * * <p> * You can use this class 2 ways. First with the constructor without a Form object then this Link * must be inside a Form so that it knows what form to submit to. Second way is to use the Form * constructor then that form will be used to submit to. * </p> * <p> * * <pre> * Form f = new Form("linkForm", new CompoundPropertyModel(mod)); * f.add(new TextField("value1")); * f.add(new SubmitLink("link1") { * protected void onSubmit() { * System.out.println("Link1 was clicked, value1 is: " * + mod.getValue1()); * }; * }); * add(new SubmitLink("link2",f) { * protected void onSubmit() { * System.out.println("Link2 was clicked, value1 is: " * + mod.getValue1()); * }; * }); * * <form wicket:id="linkForm" > * <input wicket:id="value1" type="text" size="30"/> * <a wicket:id="link1">Press link1 to submit</a> * <input type="submit" value="Send"/> * </form> * <a wicket:id="link2">Press link 2 to submit</a> * </pre> * * </p> * <p> * If this link is not placed in a form or given a form to cooperate with, it will fall back to a * normal link behavior, meaning that {@link #onSubmit()} will be called without any other * consequences. * </p> * <p> * To customize the JavaScript code used to submit the form we must override {@link #getTriggerJavaScript()}. * This can be helpful to implement additional client side behaviors like disabling the link during form submission. * </p> * * @author chris * @author jcompagner * @author Igor Vaynberg (ivaynberg) * @author Eelco Hillenius * */ public class SubmitLink extends AbstractSubmitLink implements IRequestListener { private static final long serialVersionUID = 1L; /** * With this constructor the SubmitLink must be inside a Form. * * @param id * The id of the submitlink. */ public SubmitLink(String id) { super(id); } /** * With this constructor the SubmitLink will submit the {@link Form} that is given when the link * is clicked on. * * The SubmitLink doesn't have to be inside the {@link Form}. But currently if it is outside the * {@link Form} and the SubmitLink is rendered first, then the {@link Form} will have a * generated javascript/css id. The markup javascript/css id that can exist will be overridden. * * @param id * The id of the submitlink. * @param form * The form which this submitlink must submit. */ public SubmitLink(String id, Form<?> form) { super(id, form); } /** * With this constructor the SubmitLink must be inside a Form. * * @param id * The id of the submitlink. * @param model * The model for this submitlink, It won't be used by the submit link itself, but it * can be used for keeping state */ public SubmitLink(String id, IModel<?> model) { super(id, model); } /** * With this constructor the SubmitLink will submit the {@link Form} that is given when the link * is clicked on. * * The SubmitLink doesn't have to be in inside the {@link Form}. But currently if it is outside * the {@link Form} and the SubmitLink will be rendered first. Then the {@link Form} will have a * generated javascript/css id. The markup javascript/css id that can exist will be overridden. * * @param id * The id of the submitlink. * @param model * The model for this submitlink, It won't be used by the submit link itself, but it * can be used for keeping state * @param form * The form which this submitlink must submit. */ public SubmitLink(String id, IModel<?> model, Form<?> form) { super(id, model, form); } /** * This method is here as a means to fall back on normal link behavior when this link is not * nested in a form. Not intended to be called by clients directly. * * @see org.apache.wicket.markup.html.link.ILinkListener#onLinkClicked() */ public final void onLinkClicked() { onSubmit(); onAfterSubmit(); } /** * @see org.apache.wicket.Component#onComponentTag(org.apache.wicket.markup.ComponentTag) */ @Override protected void onComponentTag(ComponentTag tag) { super.onComponentTag(tag); if (isEnabledInHierarchy()) { if (tag.getName().equalsIgnoreCase("a") || tag.getName().equalsIgnoreCase("link") || tag.getName().equalsIgnoreCase("area")) { tag.put("href", "javascript:;"); } else if (tag.getName().equalsIgnoreCase("button")) { // WICKET-5597 prevent default submit tag.put("type", "button"); } tag.put("onclick", getTriggerJavaScript()); } else { disableLink(tag); } } /** * Controls whether or not clicking on this link will invoke form's javascript onsubmit handler. * True by default. * * @return true if form's javascript onsubmit handler should be invoked, false otherwise */ protected boolean shouldInvokeJavaScriptFormOnsubmit() { return true; } /** * The JavaScript which triggers this link. Method is non-final so that subclasses can decorate * the provided script by wrapping their own JS around a call to super.getTriggerJavaScript(). * * @return The JavaScript to be executed when the link is clicked. */ protected CharSequence getTriggerJavaScript() { if (getForm() != null) { // find the root form - the one we are really going to submit Form<?> root = getForm().getRootForm(); StringBuilder script = new StringBuilder(); if (shouldInvokeJavaScriptFormOnsubmit()) { script.append(String.format("var ff=document.getElementById('%s');", getForm().getMarkupId())); script.append("if (typeof ff.onsubmit === 'function' && ff.onsubmit() == false) return false;"); } script.append(root.getJsForSubmitter(this)); script.append("return false;"); return script; } else { return null; } } /** * @deprecated do not override, will be removed in Wicket 9 */ @Deprecated @Override public void onRequest() { // with WICKET-6642 SubmitLink was reverted to use a request to the form once again, // see Form#getJsForSubmitter(IFormSubmittingComponent) } /** * @see org.apache.wicket.markup.html.form.IFormSubmittingComponent#onError() */ @Override public void onError() { } /** * Override this method to provide special submit handling in a multi-button form. This method * will be called <em>after</em> the form's onSubmit method. */ @Override public void onAfterSubmit() { } /** * Override this method to provide special submit handling in a multi-button form. This method * will be called <em>before</em> the form's onSubmit method. */ @Override public void onSubmit() { } }