001/*
002 * Copyright 2010 The Kuali Foundation.
003 * 
004 * Licensed under the Educational Community License, Version 1.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 * 
008 * http://www.opensource.org/licenses/ecl1.php
009 * 
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.ole.sys.document.web.renderers;
017
018import java.io.IOException;
019
020import javax.servlet.jsp.JspException;
021import javax.servlet.jsp.JspWriter;
022import javax.servlet.jsp.PageContext;
023import javax.servlet.jsp.tagext.Tag;
024
025import org.apache.commons.lang.StringUtils;
026import org.apache.struts.taglib.html.HiddenTag;
027
028/**
029 * Render which displays a field that can't be input directly but could be changed when other fields change.
030 * An example of such is the chartOfAccountsCode in accounting lines, when accounts can't cross charts and
031 * chart code is set automatically by account number.   
032 */
033public class DynamicReadOnlyRender extends ReadOnlyRenderer {
034    // A hidden input field to store a copy of the field value so that the field will appear read-only to users
035    // but could be set by the system and read into the data object.
036    private HiddenTag shadowInputTag = new HiddenTag();
037    
038    /**
039     * @see org.kuali.ole.sys.document.web.renderers.Renderer#render(javax.servlet.jsp.PageContext, javax.servlet.jsp.tagext.Tag)
040     */
041    public void render(PageContext pageContext, Tag parentTag) throws JspException {
042        JspWriter out = pageContext.getOut();
043
044        try {
045            String value = discoverRenderValue();            
046            out.write(buildBeginSpan());
047            
048            if (!StringUtils.isEmpty(value)) {
049                if (shouldRenderInquiryLink()) {
050                    out.write(buildBeginInquiryLink());
051                }                
052                out.write(value);                
053                if (shouldRenderInquiryLink()) {
054                    out.write(buildEndInquiryLink());
055                }                                
056            } else {
057                out.write(buildNonBreakingSpace());
058            }
059            
060            out.write(buildEndSpan());
061            renderShadowInputTag(pageContext, parentTag);
062        }
063        catch (IOException ioe) {
064            throw new JspException("Difficulty rendering read only field", ioe);
065        }
066    }
067
068    /**
069     * Generates the HTML for the opening span tag to wrap the displayed value
070     * @param propertyPrefix the property path from the form the business object being rendered
071     * @return the HTML for the opening span 
072     */
073    protected String buildBeginSpan() {
074        StringBuilder beginSpan = new StringBuilder();        
075        beginSpan.append("<span id=\"");
076        beginSpan.append(getFieldName());
077        beginSpan.append(".div\">");        
078        return beginSpan.toString();
079    }    
080
081    /**
082     * Renders the value of the field in the hidden input tag so it can be read into the data object.
083     * @param pageContext the page context to render to
084     * @param parentTag the tag requesting all this rendering
085     */
086    protected void renderShadowInputTag(PageContext pageContext, Tag parentTag) throws JspException {
087        shadowInputTag.setPageContext(pageContext);
088        shadowInputTag.setParent(parentTag);
089        shadowInputTag.setProperty(getFieldName());
090        shadowInputTag.setValue(getField().getPropertyValue());        
091        shadowInputTag.doStartTag();
092        shadowInputTag.doEndTag();
093    }
094    
095}