/* Copyright 2005-2006 Tim Fennell
*
* 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 net.sourceforge.stripes.tag;
import static net.sourceforge.stripes.controller.StripesConstants.URL_KEY_FIELDS_PRESENT;
import java.util.HashSet;
import java.util.Set;
import javax.servlet.ServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TryCatchFinally;
import net.sourceforge.stripes.action.ActionBean;
import net.sourceforge.stripes.controller.ActionResolver;
import net.sourceforge.stripes.controller.StripesConstants;
import net.sourceforge.stripes.controller.StripesFilter;
import net.sourceforge.stripes.exception.StripesJspException;
import net.sourceforge.stripes.exception.StripesServletException;
import net.sourceforge.stripes.util.CryptoUtil;
import net.sourceforge.stripes.util.HtmlUtil;
/**
* <p>Examines the request and include hidden fields for all parameters that have do
* not have form fields in the current form. Will include multiple values for
* parameters that have them. Excludes 'special' parameters like the source
* page parameter, and the parameter that conveyed the event name.</p>
*
* <p>Very useful for implementing basic wizard flow without relying on session
* scoping of ActionBeans, and without having to name all the parameters that
* should be carried forward in the form.</p>
*
* @author Tim Fennell
*/
public class WizardFieldsTag extends StripesTagSupport implements TryCatchFinally {
private boolean currentFormOnly = false;
/**
* Sets whether or not the parameters should be output only if the form matches the current
* request. Defaults to false.
*/
public void setCurrentFormOnly(boolean currentFormOnly) { this.currentFormOnly = currentFormOnly; }
/** Gets whether the tag will output fields for the current form only, or in all cases. */
public boolean isCurrentFormOnly() { return currentFormOnly; }
/** Skips over the body because there shouldn't be one. */
@Override
public int doStartTag() throws JspException {
getTagStack().push(this);
return SKIP_BODY;
}
/**
* Performs the main work of the tag, as described in the class level javadoc.
* @return EVAL_PAGE in all cases.
*/
@Override
public int doEndTag() throws JspException {
// Get the current form.
FormTag form = getParentTag(FormTag.class);
// Get the action bean on this form
ActionBean actionBean = form.getActionBean();
// If current form only is not specified, go ahead, otherwise check that
// the current form had an ActionBean attached - which indicates that the
// last submit was to the same form/action as this form
if (!isCurrentFormOnly() || actionBean != null) {
writeWizardFields(form);
}
return EVAL_PAGE;
}
/** Rethrows the passed in throwable in all cases. */
public void doCatch(Throwable throwable) throws Throwable { throw throwable; }
/**
* Used to ensure that the input tag is always removed from the tag stack so that there is
* never any confusion about tag-parent hierarchies.
*/
public void doFinally() {
try { getTagStack().pop(); }
catch (Throwable t) {
/* Suppress anything, because otherwise this might mask any causal exception. */
}
}
/**
* Write out a hidden field which contains parameters that should be sent along with the actual
* form fields.
*/
protected void writeWizardFields(FormTag form) throws JspException, StripesJspException {
// Set up a hidden tag to do the writing for us
InputHiddenTag hidden = new InputHiddenTag();
hidden.setPageContext(getPageContext());
hidden.setParent(getParent());
// Get the list of all parameters.
Set<String> paramNames = getParamNames();
// Figure out the list of parameters we should not include
Set<String> excludes = getExcludes(form);
// Loop through the request parameters and output the values
Class<? extends ActionBean> actionBeanType = form.getActionBeanClass();
for (String name : paramNames) {
if (!excludes.contains(name) && !isEventName(actionBeanType, name)) {
hidden.setName(name);
try {
hidden.doStartTag();
hidden.doAfterBody();
hidden.doEndTag();
}
catch (Throwable t) {
/** Catch whatever comes back out of the doCatch() method and deal with it */
try {
hidden.doCatch(t);
}
catch (Throwable t2) {
if (t2 instanceof JspException)
throw (JspException) t2;
if (t2 instanceof RuntimeException)
throw (RuntimeException) t2;
else
throw new StripesJspException(t2);
}
}
finally {
hidden.doFinally();
}
}
}
}
/** Returns all the submitted parameters in the current or the former requests. */
@SuppressWarnings("unchecked")
protected Set<String> getParamNames() {
// Combine actual parameter names with input names from the form, which might not be
// represented by a real request parameter
Set<String> paramNames = new HashSet<String>();
ServletRequest request = getPageContext().getRequest();
paramNames.addAll(request.getParameterMap().keySet());
String fieldsPresent = request.getParameter(URL_KEY_FIELDS_PRESENT);
if (fieldsPresent != null) {
paramNames.addAll(HtmlUtil.splitValues(CryptoUtil.decrypt(fieldsPresent)));
}
return paramNames;
}
/** Returns the list of parameters that should be excluded from the hidden tag. */
protected Set<String> getExcludes(FormTag form) {
Set<String> excludes = new HashSet<String>();
excludes.addAll(form.getRegisteredFields());
excludes.add(StripesConstants.URL_KEY_SOURCE_PAGE);
excludes.add(StripesConstants.URL_KEY_FIELDS_PRESENT);
excludes.add(StripesConstants.URL_KEY_EVENT_NAME);
excludes.add(StripesConstants.URL_KEY_FLASH_SCOPE_ID);
// Use the submitted action bean to eliminate any event related parameters
ServletRequest request = getPageContext().getRequest();
ActionBean submittedActionBean = (ActionBean) request
.getAttribute(StripesConstants.REQ_ATTR_ACTION_BEAN);
if (submittedActionBean != null) {
String eventName = submittedActionBean.getContext().getEventName();
if (eventName != null) {
excludes.add(eventName);
excludes.add(eventName + ".x");
excludes.add(eventName + ".y");
}
}
return excludes;
}
/**
* Returns true if {@code name} is the name of an event handled by {@link ActionBean}s of type
* {@code beanType}.
*
* @param beanType An {@link ActionBean} class
* @param name The name to look up
*/
protected boolean isEventName(Class<? extends ActionBean> beanType, String name) {
if (beanType == null || name == null)
return false;
try {
ActionResolver actionResolver = StripesFilter.getConfiguration().getActionResolver();
return actionResolver.getHandler(beanType, name) != null;
}
catch (StripesServletException e) {
// Ignore the exception and assume the name is not an event
return false;
}
}
}