Java tutorial
/* * The Kuali Financial System, a comprehensive financial management system for higher education. * * Copyright 2005-2014 The Kuali Foundation * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.kuali.kfs.sys.document.web.renderers; import java.io.IOException; import javax.servlet.jsp.JspException; import javax.servlet.jsp.JspWriter; import javax.servlet.jsp.PageContext; import javax.servlet.jsp.tagext.Tag; import org.apache.commons.lang.StringUtils; import org.apache.struts.taglib.html.HiddenTag; /** * Render which displays a field that can't be input directly but could be changed when other fields change. * An example of such is the chartOfAccountsCode in accounting lines, when accounts can't cross charts and * chart code is set automatically by account number. */ public class DynamicReadOnlyRender extends ReadOnlyRenderer { // A hidden input field to store a copy of the field value so that the field will appear read-only to users // but could be set by the system and read into the data object. private HiddenTag shadowInputTag = new HiddenTag(); /** * @see org.kuali.kfs.sys.document.web.renderers.Renderer#render(javax.servlet.jsp.PageContext, javax.servlet.jsp.tagext.Tag) */ public void render(PageContext pageContext, Tag parentTag) throws JspException { JspWriter out = pageContext.getOut(); try { String value = discoverRenderValue(); out.write(buildBeginSpan()); if (!StringUtils.isEmpty(value)) { if (shouldRenderInquiryLink()) { out.write(buildBeginInquiryLink()); } out.write(value); if (shouldRenderInquiryLink()) { out.write(buildEndInquiryLink()); } } else { out.write(buildNonBreakingSpace()); } out.write(buildEndSpan()); renderShadowInputTag(pageContext, parentTag); } catch (IOException ioe) { throw new JspException("Difficulty rendering read only field", ioe); } } /** * Generates the HTML for the opening span tag to wrap the displayed value * @param propertyPrefix the property path from the form the business object being rendered * @return the HTML for the opening span */ protected String buildBeginSpan() { StringBuilder beginSpan = new StringBuilder(); beginSpan.append("<span id=\""); beginSpan.append(getFieldName()); beginSpan.append(".div\">"); return beginSpan.toString(); } /** * Renders the value of the field in the hidden input tag so it can be read into the data object. * @param pageContext the page context to render to * @param parentTag the tag requesting all this rendering */ protected void renderShadowInputTag(PageContext pageContext, Tag parentTag) throws JspException { shadowInputTag.setPageContext(pageContext); shadowInputTag.setParent(parentTag); shadowInputTag.setProperty(getFieldName()); shadowInputTag.setValue(getField().getPropertyValue()); shadowInputTag.doStartTag(); shadowInputTag.doEndTag(); } }