FormTagHDIV.java

/**
 * Copyright 2005-2016 hdiv.org
 *
 * Licensed 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.hdiv.taglib.html;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspException;

import org.apache.struts.Globals;
import org.apache.struts.taglib.TagUtils;
import org.apache.struts.taglib.html.FormTag;
import org.hdiv.dataComposer.IDataComposer;
import org.hdiv.urlProcessor.FormUrlProcessor;
import org.hdiv.util.HDIVUtil;

/**
 * Renders an HTML <b><form></b> element whose contents are described by the body content of this tag. The form implicitly interacts
 * with the specified request scope or session scope bean to populate the input fields with the current property values from the bean. The
 * form bean is located, and created if necessary, based on the form bean specification for the associated ActionMapping.
 *
 * @author Aritz Rabadan
 * @author Gorka Vicente
 * @see org.apache.struts.taglib.html.FormTag
 */
public class FormTagHDIV extends FormTag {

	/**
	 * Universal version identifier. Deserialization uses this number to ensure that a loaded class corresponds exactly to a serialized
	 * object.
	 */
	private static final long serialVersionUID = 5073853465806606664L;

	protected FormUrlProcessor formUrlProcessor;

	/**
	 * Renders the action attribute
	 * @see org.hdiv.dataComposer.IDataComposer
	 * @see org.hdiv.urlProcessor.FormUrlProcessor
	 */
	@Override
	protected void renderAction(final StringBuffer results) {

		final HttpServletResponse response = (HttpServletResponse) pageContext.getResponse();
		final HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();

		final String calcAction = (action == null ? getPostbackAction() : action);

		final String url = response.encodeURL(TagUtils.getInstance().getActionMappingURL(calcAction, pageContext));

		// Call to Hdiv FormUrlProcessor
		if (formUrlProcessor == null) {
			formUrlProcessor = HDIVUtil.getFormUrlProcessor(request.getSession().getServletContext());
		}
		final String encodedURL = formUrlProcessor.processUrl(request, url);

		results.append(" action=\"");
		results.append(encodedURL);
		results.append("\"");
	}

	/**
	 * @return If the action is not specified returns the original request uri.
	 */
	public String getPostbackAction() {
		final HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
		String tempPostbackAction = (String) request.getAttribute(Globals.ORIGINAL_URI_KEY);

		final String prefix = moduleConfig.getPrefix();
		if (tempPostbackAction != null && prefix.length() > 0 && tempPostbackAction.startsWith(prefix)) {
			tempPostbackAction = tempPostbackAction.substring(prefix.length());
		}
		return tempPostbackAction;
	}

	/**
	 * Render the end of this form adding HDIV parameter if strategy is cipher or hash.
	 * @exception JspException if a JSP exception has occurred
	 */
	@Override
	public int doEndTag() throws JspException {

		addHDIVParameter();
		return super.doEndTag();
	}

	/**
	 * Adds HDIV state as parameter.
	 */
	protected void addHDIVParameter() throws JspException {

		final HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
		final IDataComposer dataComposer = HDIVUtil.getDataComposer(request);
		if (!dataComposer.isRequestStarted()) {
			return;
		}
		final String requestId = dataComposer.endRequest();

		if (requestId.length() > 0) {
			TagUtils.getInstance().write(pageContext, generateHiddenTag(dataComposer.getHdivParameterName(), requestId));
		}
	}

	/**
	 * Renders an HTML <b><input></b> element of type hidden.
	 *
	 * @param name hidden parameter name
	 * @param requestId request identification
	 * @return HTML <b><input></b> element of type hidden
	 */
	private String generateHiddenTag(final String name, final String requestId) {

		final StringBuffer hdivParameter = new StringBuffer(32);

		hdivParameter.append("<input type=\"hidden\"");
		renderAttribute(hdivParameter, "name", name);
		renderAttribute(hdivParameter, "value", requestId);
		hdivParameter.append(">\n");

		return hdivParameter.toString();
	}

}