/*
* Copyright 2002-2009 the original author or authors.
*
* 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.springframework.web.portlet.mvc;
import java.util.Arrays;
import java.util.Map;
import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.PortletException;
import javax.portlet.PortletRequest;
import javax.portlet.PortletSession;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import org.springframework.validation.BindException;
import org.springframework.validation.Errors;
import org.springframework.web.portlet.ModelAndView;
import org.springframework.web.portlet.bind.PortletRequestDataBinder;
import org.springframework.web.portlet.handler.PortletSessionRequiredException;
/**
* <p>Form controller that auto-populates a form bean from the request.
* This, either using a new bean instance per request, or using the same bean
* when the <code>sessionForm</code> property has been set to
* <code>true</code>.</p>
*
* <p>This class is the base class for both framework subclasses such as
* {@link SimpleFormController} and {@link AbstractWizardFormController}
* and custom form controllers that you may provide yourself.</p>
*
* <p>A form-input view and an after-submission view have to be provided
* programmatically. To provide those views using configuration properties,
* use the {@link SimpleFormController}.</p>
*
* <p>Subclasses need to override <code>showForm</code> to prepare the form view,
* <code>processFormSubmission</code> to handle submit requests, and
* <code>renderFormSubmission</code> to display the results of the submit.
* For the latter two methods, binding errors like type mismatches will be
* reported via the given "errors" holder. For additional custom form validation,
* a validator (property inherited from BaseCommandController) can be used,
* reporting via the same "errors" instance.</p>
*
* <p>Comparing this Controller to the Struts notion of the <code>Action</code>
* shows us that with Spring, you can use any ordinary JavaBeans or database-
* backed JavaBeans without having to implement a framework-specific class
* (like Struts' <code>ActionForm</code>). More complex properties of JavaBeans
* (Dates, Locales, but also your own application-specific or compound types)
* can be represented and submitted to the controller, by using the notion of
* a <code>java.beans.PropertyEditors</code>. For more information on that
* subject, see the workflow of this controller and the explanation of the
* {@link BaseCommandController BaseCommandController}.</p>
*
* <p>This controller is different from it's servlet counterpart in that it must take
* into account the two phases of a portlet request: the action phase and the render
* phase. See the JSR-168 spec for more details on these two phases.
* Be especially aware that the action phase is called only once, but that the
* render phase will be called repeatedly by the portal; it does this every time
* the page containing the portlet is updated, even if the activity is in some other
* portlet. (This is not quite true, the portal can also be told to cache the results of
* the render for a period of time, but assume it is true for programming purposes.)</p>
*
* <p><b><a name="workflow">Workflow
* (<a href="BaseCommandController.html#workflow">and that defined by superclass</a>):</b><br>
* <ol>
* <li><b>The controller receives a request for a new form (typically a
* Render Request only).</b> The render phase will proceed to display
* the form as follows.</li>
* <li>Call to {@link #formBackingObject formBackingObject()} which by
* default, returns an instance of the commandClass that has been
* configured (see the properties the superclass exposes), but can also be
* overridden to e.g. retrieve an object from the database (that needs to
* be modified using the form).</li>
* <li>Call to {@link #initBinder initBinder()} which allows you to
* register custom editors for certain fields (often properties of non-
* primitive or non-String types) of the command class. This will render
* appropriate Strings for those property values, e.g. locale-specific
* date strings. </li>
* <li>The {@link PortletRequestDataBinder PortletRequestDataBinder}
* gets applied to populate the new form object with initial request parameters and the
* {@link #onBindOnNewForm(RenderRequest, Object, BindException)} callback method is invoked.
* (<i>only if <code>bindOnNewForm</code> is set to <code>true</code></i>)
* Make sure that the initial parameters do not include the parameter that indicates a
* form submission has occurred.</li>
* <li>Call to {@link #showForm(RenderRequest, RenderResponse,
* BindException) showForm} to return a View that should be rendered
* (typically the view that renders the form). This method has to be
* implemented in subclasses. </li>
* <li>The showForm() implementation will call {@link #referenceData referenceData},
* which you can implement to provide any relevant reference data you might need
* when editing a form (e.g. a List of Locale objects you're going to let the
* user select one from).</li>
* <li>Model gets exposed and view gets rendered, to let the user fill in
* the form.</li>
* <li><b>The controller receives a form submission (typically an Action
* Request).</b> To use a different way of detecting a form submission,
* override the {@link #isFormSubmission isFormSubmission} method.
* The action phase will proceed to process the form submission as follows.</li>
* <li>If <code>sessionForm</code> is not set, {@link #formBackingObject
* formBackingObject} is called to retrieve a form object. Otherwise,
* the controller tries to find the command object which is already bound
* in the session. If it cannot find the object, the action phase does a
* call to {@link #handleInvalidSubmit handleInvalidSubmit} which - by default -
* tries to create a new form object and resubmit the form. It then sets
* a render parameter that will indicate to the render phase that this was
* an invalid submit.</li>
* <li>Still in the action phase of a valid submit, the {@link
* PortletRequestDataBinder PortletRequestDataBinder} gets applied to populate
* the form object with current request parameters.</li>
* <li>Call to {@link #onBind onBind(PortletRequest, Object, Errors)}
* which allows you to do custom processing after binding but before
* validation (e.g. to manually bind request parameters to bean
* properties, to be seen by the Validator).</li>
* <li>If <code>validateOnBinding</code> is set, a registered Validator
* will be invoked. The Validator will check the form object properties,
* and register corresponding errors via the given {@link Errors Errors}
* object.</li>
* <li>Call to {@link #onBindAndValidate onBindAndValidate} which allows
* you to do custom processing after binding and validation (e.g. to
* manually bind request parameters, and to validate them outside a
* Validator).</li>
* <li>Call to {@link #processFormSubmission processFormSubmission}
* to process the submission, with or without binding errors.
* This method has to be implemented in subclasses and will be called
* only once per form submission.</li>
* <li>The portal will then call the render phase of processing the form
* submission. This phase will be called repeatedly by the portal every
* time the page is refreshed. All processing here should take this into
* account. Any one-time-only actions (such as modifying a database) must
* be done in the action phase.</li>
* <li>If the action phase indicated this is an invalid submit, the render
* phase calls {@link #renderInvalidSubmit renderInvalidSubmit} which –
* also by default – will render the results of the resubmitted
* form. Be sure to override both <code>handleInvalidSubmit</code> and
* <code>renderInvalidSubmit</code> if you want to change this overall
* behavior.</li>
* <li>Finally, call {@link #renderFormSubmission renderFormSubmission} to
* render the results of the submission, with or without binding errors.
* This method has to be implemented in subclasses and will be called
* repeatedly by the portal.</li>
* </ol>
* </p>
*
* <p>In session form mode, a submission without an existing form object in the
* session is considered invalid, like in the case of a resubmit/reload by the browser.
* The {@link #handleInvalidSubmit handleInvalidSubmit} /
* {@link #renderInvalidSubmit renderInvalidSubmit} methods are invoked then,
* by default trying to resubmit. This can be overridden in subclasses to show
* corresponding messages or to redirect to a new form, in order to avoid duplicate
* submissions. The form object in the session can be considered a transaction token
* in that case.</p>
*
* <p>Make sure that any URLs that take you to your form controller are Render URLs,
* so that it will not try to treat the initial call as a form submission.
* If you use action URLs to link to your controller, you will need to override the
* {@link #isFormSubmission isFormSubmission} method to use a different mechanism for
* determining whether a form has been submitted. Make sure this method will work for
* both the ActionRequest and the RenderRequest objects.</p>
*
* <p>Note that views should never retrieve form beans from the session but always
* from the request, as prepared by the form controller. Remember that some view
* technologies like Velocity cannot even access a HTTP session.</p>
*
* <p><b><a name="config">Exposed configuration properties</a>
* (<a href="BaseCommandController.html#config">and those defined by superclass</a>):</b><br>
* <table border="1">
* <tr>
* <td><b>name</b></td>
* <td><b>default</b></td>
* <td><b>description</b></td>
* </tr>
* <tr>
* <td>bindOnNewForm</td>
* <td>false</td>
* <td>Indicates whether to bind portlet request parameters when
* creating a new form. Otherwise, the parameters will only be
* bound on form submission attempts.</td>
* </tr>
* <tr>
* <td>sessionForm</td>
* <td>false</td>
* <td>Indicates whether the form object should be kept in the session
* when a user asks for a new form. This allows you e.g. to retrieve
* an object from the database, let the user edit it, and then persist
* it again. Otherwise, a new command object will be created for each
* request (even when showing the form again after validation errors).</td>
* </tr>
* <tr>
* <td>redirectAction</td>
* <td>false</td>
* <td>Specifies whether <code>processFormSubmission</code> is expected to call
* {@link ActionResponse#sendRedirect ActionResponse.sendRedirect}.
* This is important because some methods may not be called before
* {@link ActionResponse#sendRedirect ActionResponse.sendRedirect} (e.g.
* {@link ActionResponse#setRenderParameter ActionResponse.setRenderParameter}).
* Setting this flag will prevent AbstractFormController from setting render
* parameters that it normally needs for the render phase.
* If this is set true and <code>sendRedirect</code> is not called, then
* <code>processFormSubmission</code> must call
* {@link #setFormSubmit setFormSubmit}.
* Otherwise, the render phase will not realize the form was submitted
* and will simply display a new blank form.</td>
* </tr>
* <tr>
* <td>renderParameters</td>
* <td>null</td>
* <td>An array of parameters that will be passed forward from the action
* phase to the render phase if the form needs to be displayed
* again. These can also be passed forward explicitly by calling
* the <code>passRenderParameters</code> method from any action
* phase method. Abstract descendants of this controller should follow
* similar behavior. If there are parameters you need in
* <code>renderFormSubmission</code>, then you need to pass those
* forward from <code>processFormSubmission</code>. If you override the
* default behavior of invalid submits and you set sessionForm to true,
* then you probably will not need to set this because your parameters
* are only going to be needed on the first request.</td>
* </tr>
* </table>
* </p>
*
* <p>Thanks to Rainer Schmitz and Nick Lothian for their suggestions!
*
* @author John A. Lewis
* @author Juergen Hoeller
* @author Alef Arendsen
* @author Rob Harrop
* @since 2.0
* @see #showForm(RenderRequest, RenderResponse, BindException)
* @see SimpleFormController
* @see AbstractWizardFormController
* @deprecated as of Spring 3.0, in favor of annotated controllers
*/
@Deprecated
public abstract class AbstractFormController extends BaseCommandController {
/**
* These render parameters are used to indicate forward to the render phase
* if the form was submitted and if the submission was invalid.
*/
private static final String FORM_SUBMISSION_PARAMETER = "form-submit";
private static final String INVALID_SUBMISSION_PARAMETER = "invalid-submit";
private static final String TRUE = Boolean.TRUE.toString();
private boolean bindOnNewForm = false;
private boolean sessionForm = false;
private boolean redirectAction = false;
private String[] renderParameters = null;
/**
* Create a new AbstractFormController.
* <p>Subclasses should set the following properties, either in the constructor
* or via a BeanFactory: commandName, commandClass, bindOnNewForm, sessionForm.
* Note that commandClass doesn't need to be set when overriding
* <code>formBackingObject</code>, as the latter determines the class anyway.
* <p>"cacheSeconds" is by default set to 0 (-> no caching for all form controllers).
* @see #setCommandName
* @see #setCommandClass
* @see #setBindOnNewForm
* @see #setSessionForm
* @see #formBackingObject
*/
public AbstractFormController() {
setCacheSeconds(0);
}
/**
* Set if request parameters should be bound to the form object
* in case of a non-submitting request, i.e. a new form.
*/
public final void setBindOnNewForm(boolean bindOnNewForm) {
this.bindOnNewForm = bindOnNewForm;
}
/**
* Return if request parameters should be bound in case of a new form.
*/
public final boolean isBindOnNewForm() {
return this.bindOnNewForm;
}
/**
* Activate/deactivate session form mode. In session form mode,
* the form is stored in the session to keep the form object instance
* between requests, instead of creating a new one on each request.
* <p>This is necessary for either wizard-style controllers that populate a
* single form object from multiple pages, or forms that populate a persistent
* object that needs to be identical to allow for tracking changes.
*/
public final void setSessionForm(boolean sessionForm) {
this.sessionForm = sessionForm;
}
/**
* Return if session form mode is activated.
*/
public final boolean isSessionForm() {
return this.sessionForm;
}
/**
* Specify whether the action phase is expected to call
* {@link ActionResponse#sendRedirect}.
* This information is important because some methods may not be called
* before {@link ActionResponse#sendRedirect}, e.g.
* {@link ActionResponse#setRenderParameter} and
* {@link ActionResponse#setRenderParameters}.
* <p><b>NOTE:</b> Call this at initialization time of your controller:
* either in the constructor or in the bean definition for your controller.
* @see ActionResponse#sendRedirect
*/
public void setRedirectAction(boolean redirectAction) {
this.redirectAction = redirectAction;
}
/**
* Return if {@link ActionResponse#sendRedirect} is
* expected to be called in the action phase.
*/
public boolean isRedirectAction() {
return this.redirectAction;
}
/**
* Specify the list of parameters that should be passed forward
* from the action phase to the render phase whenever the form is
* re-rendered or when {@link #passRenderParameters} is called.
* @see #passRenderParameters
*/
public void setRenderParameters(String[] parameters) {
this.renderParameters = parameters;
}
/**
* Returns the list of parameters that will be passed forward
* from the action phase to the render phase whenever the form is
* rerendered or when {@link #passRenderParameters} is called.
* @return the list of parameters
* @see #passRenderParameters
*/
public String[] getRenderParameters() {
return this.renderParameters;
}
/**
* Handles action phase of two cases: form submissions and showing a new form.
* Delegates the decision between the two to <code>isFormSubmission</code>,
* always treating requests without existing form session attribute
* as new form when using session form mode.
* @see #isFormSubmission
* @see #processFormSubmission
* @see #handleRenderRequestInternal
*/
@Override
protected void handleActionRequestInternal(ActionRequest request, ActionResponse response)
throws Exception {
// Form submission or new form to show?
if (isFormSubmission(request)) {
// Fetch form object, bind, validate, process submission.
try {
Object command = getCommand(request);
if (logger.isDebugEnabled()) {
logger.debug("Processing valid submit (redirectAction = " + isRedirectAction() + ")");
}
if (!isRedirectAction()) {
setFormSubmit(response);
}
PortletRequestDataBinder binder = bindAndValidate(request, command);
BindException errors = new BindException(binder.getBindingResult());
processFormSubmission(request, response, command, errors);
setRenderCommandAndErrors(request, command, errors);
return;
}
catch (PortletSessionRequiredException ex) {
// Cannot submit a session form if no form object is in the session.
if (logger.isDebugEnabled()) {
logger.debug("Invalid submit detected: " + ex.getMessage());
}
setFormSubmit(response);
setInvalidSubmit(response);
handleInvalidSubmit(request, response);
return;
}
}
else {
logger.debug("Not a form submit - passing parameters to render phase");
passRenderParameters(request, response);
return;
}
}
/**
* Handles render phase of two cases: form submissions and showing a new form.
* Delegates the decision between the two to <code>isFormSubmission</code>,
* always treating requests without existing form session attribute
* as new form when using session form mode.
* @see #isFormSubmission
* @see #showNewForm
* @see #processFormSubmission
* @see #handleActionRequestInternal
*/
@Override
protected ModelAndView handleRenderRequestInternal(RenderRequest request, RenderResponse response)
throws Exception {
// Form submission or new form to show?
if (isFormSubmission(request)) {
// If it is an invalid submit then handle it.
if (isInvalidSubmission(request)) {
logger.debug("Invalid submit - calling renderInvalidSubmit");
return renderInvalidSubmit(request, response);
}
// Valid submit -> render.
logger.debug("Valid submit - calling renderFormSubmission");
return renderFormSubmission(request, response, getRenderCommand(request), getRenderErrors(request));
}
else {
// New form to show: render form view.
return showNewForm(request, response);
}
}
/**
* Determine if the given request represents a form submission.
* <p>The default implementation checks to see if this is an ActionRequest
* and treats all action requests as form submission. During the action
* phase it will pass forward a render parameter to indicate to the render
* phase that this is a form submission. This method can check both
* kinds of requests and indicate if this is a form submission.
* <p>Subclasses can override this to use a custom strategy, e.g. a specific
* request parameter (assumably a hidden field or submit button name). Make
* sure that the override can handle both ActionRequest and RenderRequest
* objects properly.
* @param request current request
* @return if the request represents a form submission
*/
protected boolean isFormSubmission(PortletRequest request) {
return (request instanceof ActionRequest || TRUE.equals(request.getParameter(getFormSubmitParameterName())));
}
/**
* Determine if the given request represents an invalid form submission.
*/
protected boolean isInvalidSubmission(PortletRequest request) {
return TRUE.equals(request.getParameter(getInvalidSubmitParameterName()));
}
/**
* Return the name of the render parameter that indicates this
* was a form submission.
* @return the name of the render parameter
* @see javax.portlet.RenderRequest#getParameter
*/
protected String getFormSubmitParameterName() {
return FORM_SUBMISSION_PARAMETER;
}
/**
* Return the name of the render parameter that indicates this
* was an invalid form submission.
* @return the name of the render parameter
* @see javax.portlet.RenderRequest#getParameter
*/
protected String getInvalidSubmitParameterName() {
return INVALID_SUBMISSION_PARAMETER;
}
/**
* Set the action response parameter that indicates this in a form submission.
* @param response the current action response
* @see #getFormSubmitParameterName()
*/
protected final void setFormSubmit(ActionResponse response) {
if (logger.isDebugEnabled()) {
logger.debug("Setting render parameter [" + getFormSubmitParameterName() +
"] to indicate this is a form submission");
}
try {
response.setRenderParameter(getFormSubmitParameterName(), TRUE);
}
catch (IllegalStateException ex) {
// Ignore in case sendRedirect was already set.
}
}
/**
* Set the action response parameter that indicates this in an invalid submission.
* @param response the current action response
* @see #getInvalidSubmitParameterName()
*/
protected final void setInvalidSubmit(ActionResponse response) {
if (logger.isDebugEnabled()) {
logger.debug("Setting render parameter [" + getInvalidSubmitParameterName() +
"] to indicate this is an invalid submission");
}
try {
response.setRenderParameter(getInvalidSubmitParameterName(), TRUE);
}
catch (IllegalStateException ex) {
// Ignore in case sendRedirect was already set.
}
}
/**
* Return the name of the PortletSession attribute that holds the form object
* for this form controller.
* <p>The default implementation delegates to the
* <code>getFormSessionAttributeName</code> version without arguments.
* @param request current HTTP request
* @return the name of the form session attribute,
* or <code>null</code> if not in session form mode
* @see #getFormSessionAttributeName()
* @see javax.portlet.PortletSession#getAttribute
*/
protected String getFormSessionAttributeName(PortletRequest request) {
return getFormSessionAttributeName();
}
/**
* Return the name of the PortletSession attribute that holds the form object
* for this form controller.
* <p>Default is an internal name, of no relevance to applications, as the form
* session attribute is not usually accessed directly. Can be overridden to use
* an application-specific attribute name, which allows other code to access
* the session attribute directly.
* @return the name of the form session attribute
* @see javax.portlet.PortletSession#getAttribute
*/
protected String getFormSessionAttributeName() {
return getClass().getName() + ".FORM." + getCommandName();
}
/**
* Pass the specified list of action request parameters to the render phase
* by putting them into the action response object. This may not be called
* when the action will call will call
* {@link ActionResponse#sendRedirect sendRedirect}.
* @param request the current action request
* @param response the current action response
* @see ActionResponse#setRenderParameter
*/
protected void passRenderParameters(ActionRequest request, ActionResponse response) {
if (this.renderParameters == null) {
return;
}
try {
for (int i = 0; i < this.renderParameters.length; i++) {
String paramName = this.renderParameters[i];
String paramValues[] = request.getParameterValues(paramName);
if (paramValues != null) {
if (logger.isDebugEnabled()) {
logger.debug("Passing parameter to render phase '" + paramName + "' = " +
(paramValues == null ? "NULL" : Arrays.asList(paramValues).toString()));
}
response.setRenderParameter(paramName, paramValues);
}
}
}
catch (IllegalStateException ex) {
// Ignore in case sendRedirect was already set.
}
}
/**
* Show a new form. Prepares a backing object for the current form
* and the given request, including checking its validity.
* @param request current render request
* @param response current render response
* @return the prepared form view
* @throws Exception in case of an invalid new form object
* @see #getErrorsForNewForm
*/
protected final ModelAndView showNewForm(RenderRequest request, RenderResponse response)
throws Exception {
logger.debug("Displaying new form");
return showForm(request, response, getErrorsForNewForm(request));
}
/**
* Create a BindException instance for a new form.
* Called by <code>showNewForm</code>.
* <p>Can be used directly when intending to show a new form but with
* special errors registered on it (for example, on invalid submit).
* Usually, the resulting BindException will be passed to
* <code>showForm</code>, after registering the errors on it.
* @param request current render request
* @return the BindException instance
* @throws Exception in case of an invalid new form object
*/
protected final BindException getErrorsForNewForm(RenderRequest request) throws Exception {
// Create form-backing object for new form
Object command = formBackingObject(request);
if (command == null) {
throw new PortletException("Form object returned by formBackingObject() must not be null");
}
if (!checkCommand(command)) {
throw new PortletException("Form object returned by formBackingObject() must match commandClass");
}
// Bind without validation, to allow for prepopulating a form, and for
// convenient error evaluation in views (on both first attempt and resubmit).
PortletRequestDataBinder binder = createBinder(request, command);
BindException errors = new BindException(binder.getBindingResult());
if (isBindOnNewForm()) {
if (logger.isDebugEnabled()) {
logger.debug("Binding to new form");
}
binder.bind(request);
onBindOnNewForm(request, command, errors);
}
// Return BindException object that resulted from binding.
return errors;
}
/**
* Callback for custom post-processing in terms of binding for a new form.
* Called when preparing a new form if <code>bindOnNewForm</code> is <code>true</code>.
* <p>Default implementation delegates to <code>onBindOnNewForm(request, command)</code>.
* @param request current render request
* @param command the command object to perform further binding on
* @param errors validation errors holder, allowing for additional
* custom registration of binding errors
* @throws Exception in case of invalid state or arguments
* @see #onBindOnNewForm(RenderRequest, Object)
* @see #setBindOnNewForm
*/
protected void onBindOnNewForm(RenderRequest request, Object command, BindException errors)
throws Exception {
onBindOnNewForm(request, command);
}
/**
* Callback for custom post-processing in terms of binding for a new form.
* Called by the default implementation of the <code>onBindOnNewForm</code> version
* with all parameters, after standard binding when displaying the form view.
* Only called if <code>bindOnNewForm</code> is set to <code>true</code>.
* <p>The default implementation is empty.
* @param request current render request
* @param command the command object to perform further binding on
* @throws Exception in case of invalid state or arguments
* @see #onBindOnNewForm(RenderRequest, Object, BindException)
* @see #setBindOnNewForm(boolean)
*/
protected void onBindOnNewForm(RenderRequest request, Object command) throws Exception {
}
/**
* Return the form object for the given request.
* <p>Calls <code>formBackingObject</code> if the object is not in the session
* @param request current request
* @return object form to bind onto
* @see #formBackingObject
*/
@Override
protected final Object getCommand(PortletRequest request) throws Exception {
// If not in session-form mode, create a new form-backing object.
if (!isSessionForm()) {
return formBackingObject(request);
}
// Session-form mode: retrieve form object from portlet session attribute.
PortletSession session = request.getPortletSession(false);
if (session == null) {
throw new PortletSessionRequiredException("Must have session when trying to bind (in session-form mode)");
}
String formAttrName = getFormSessionAttributeName(request);
Object sessionFormObject = session.getAttribute(formAttrName);
if (sessionFormObject == null) {
throw new PortletSessionRequiredException("Form object not found in session (in session-form mode)");
}
// Remove form object from porlet session: we might finish the form workflow
// in this request. If it turns out that we need to show the form view again,
// we'll re-bind the form object to the portlet session.
if (logger.isDebugEnabled()) {
logger.debug("Removing form session attribute [" + formAttrName + "]");
}
session.removeAttribute(formAttrName);
// Check the command object to make sure its valid
if (!checkCommand(sessionFormObject)) {
throw new PortletSessionRequiredException("Object found in session does not match commandClass");
}
return sessionFormObject;
}
/**
* Retrieve a backing object for the current form from the given request.
* <p>The properties of the form object will correspond to the form field values
* in your form view. This object will be exposed in the model under the specified
* command name, to be accessed under that name in the view: for example, with
* a "spring:bind" tag. The default command name is "command".
* <p>Note that you need to activate session form mode to reuse the form-backing
* object across the entire form workflow. Else, a new instance of the command
* class will be created for each submission attempt, just using this backing
* object as template for the initial form.
* <p>The default implementation calls <code>BaseCommandController.createCommand</code>,
* creating a new empty instance of the command class.
* Subclasses can override this to provide a preinitialized backing object.
* @param request current portlet request
* @return the backing object
* @throws Exception in case of invalid state or arguments
* @see #setCommandName
* @see #setCommandClass
* @see #createCommand
*/
protected Object formBackingObject(PortletRequest request) throws Exception {
return createCommand();
}
/**
* Prepare the form model and view, including reference and error data.
* Can show a configured form page, or generate a form view programmatically.
* <p>A typical implementation will call
* <code>showForm(request, errors, "myView")</code>
* to prepare the form view for a specific view name, returning the
* ModelAndView provided there.
* <p>For building a custom ModelAndView, call <code>errors.getModel()</code>
* to populate the ModelAndView model with the command and the Errors instance,
* under the specified command name, as expected by the "spring:bind" tag.
* You also need to include the model returned by <code>referenceData</code>.
* <p>Note: If you decide to have a "formView" property specifying the
* view name, consider using SimpleFormController.
* @param request current render request
* @param response current render response
* @param errors validation errors holder
* @return the prepared form view, or null if handled directly
* @throws Exception in case of invalid state or arguments
* @see #showForm(RenderRequest, BindException, String)
* @see org.springframework.validation.Errors
* @see org.springframework.validation.BindException#getModel
* @see #referenceData(PortletRequest, Object, Errors)
* @see SimpleFormController#setFormView
*/
protected abstract ModelAndView showForm(RenderRequest request, RenderResponse response, BindException errors) throws Exception;
/**
* Prepare model and view for the given form, including reference and errors.
* <p>In session form mode: Re-puts the form object in the session when
* returning to the form, as it has been removed by getCommand.
* <p>Can be used in subclasses to redirect back to a specific form page.
* @param request current render request
* @param errors validation errors holder
* @param viewName name of the form view
* @return the prepared form view
* @throws Exception in case of invalid state or arguments
* @see #showForm(RenderRequest, BindException, String, Map)
* @see #showForm(RenderRequest, RenderResponse, BindException)
*/
protected final ModelAndView showForm(RenderRequest request, BindException errors, String viewName)
throws Exception {
return showForm(request, errors, viewName, null);
}
/**
* Prepare model and view for the given form, including reference and errors,
* adding a controller-specific control model.
* <p>In session form mode: Re-puts the form object in the session when returning
* to the form, as it has been removed by getCommand.
* <p>Can be used in subclasses to redirect back to a specific form page.
* @param request current render request
* @param errors validation errors holder
* @param viewName name of the form view
* @param controlModel model map containing controller-specific control data
* (e.g. current page in wizard-style controllers or special error message)
* @return the prepared form view
* @throws Exception in case of invalid state or arguments
* @see #showForm(RenderRequest, BindException, String)
* @see #showForm(RenderRequest, RenderResponse, BindException)
*/
protected final ModelAndView showForm(RenderRequest request, BindException errors, String viewName, Map controlModel)
throws Exception {
// In session form mode, re-expose form object as portlet session attribute.
// Re-binding is necessary for proper state handling in a cluster,
// to notify other nodes of changes in the form object.
if (isSessionForm()) {
String formAttrName = getFormSessionAttributeName(request);
if (logger.isDebugEnabled()) {
logger.debug("Setting form session attribute [" + formAttrName + "] to: " + errors.getTarget());
}
request.getPortletSession().setAttribute(formAttrName, errors.getTarget());
}
// Fetch errors model as starting point, containing form object under
// "commandName", and corresponding Errors instance under internal key.
Map model = errors.getModel();
// Merge reference data into model, if any.
Map referenceData = referenceData(request, errors.getTarget(), errors);
if (referenceData != null) {
model.putAll(referenceData);
}
// Merge control attributes into model, if any.
if (controlModel != null) {
model.putAll(controlModel);
}
// Trigger rendering of the specified view, using the final model.
return new ModelAndView(viewName, model);
}
/**
* Create a reference data map for the given request, consisting of
* bean name/bean instance pairs as expected by ModelAndView.
* <p>The default implementation returns <code>null</code>.
* Subclasses can override this to set reference data used in the view.
* @param request current render request
* @param command form object with request parameters bound onto it
* @param errors validation errors holder
* @return a Map with reference data entries, or null if none
* @throws Exception in case of invalid state or arguments
* @see ModelAndView
*/
protected Map referenceData(PortletRequest request, Object command, Errors errors) throws Exception {
return null;
}
/**
* Process render phase of form submission request. Called by <code>handleRequestInternal</code>
* in case of a form submission, with or without binding errors. Implementations
* need to proceed properly, typically showing a form view in case of binding
* errors or rendering the result of a submit action else.
* <p>For a success view, call <code>errors.getModel()</code> to populate the
* ModelAndView model with the command and the Errors instance, under the
* specified command name, as expected by the "spring:bind" tag. For a form view,
* simply return the ModelAndView object privded by <code>showForm</code>.
* @param request current render request
* @param response current render response
* @param command form object with request parameters bound onto it
* @param errors errors holder
* @return the prepared model and view, or null
* @throws Exception in case of errors
* @see #handleRenderRequestInternal
* @see #processFormSubmission
* @see #isFormSubmission
* @see #showForm(RenderRequest, RenderResponse, BindException)
* @see org.springframework.validation.Errors
* @see org.springframework.validation.BindException#getModel
*/
protected abstract ModelAndView renderFormSubmission(RenderRequest request, RenderResponse response, Object command, BindException errors)
throws Exception;
/**
* Process action phase of form submission request. Called by <code>handleRequestInternal</code>
* in case of a form submission, with or without binding errors. Implementations
* need to proceed properly, typically performing a submit action if there are no binding errors.
* <p>Subclasses can implement this to provide custom submission handling
* like triggering a custom action. They can also provide custom validation
* or proceed with the submission accordingly.
* @param request current action request
* @param response current action response
* @param command form object with request parameters bound onto it
* @param errors errors holder (subclass can add errors if it wants to)
* @throws Exception in case of errors
* @see #handleActionRequestInternal
* @see #renderFormSubmission
* @see #isFormSubmission
* @see org.springframework.validation.Errors
*/
protected abstract void processFormSubmission(ActionRequest request, ActionResponse response, Object command, BindException errors)
throws Exception;
/**
* Handle an invalid submit request, e.g. when in session form mode but no form object
* was found in the session (like in case of an invalid resubmit by the browser).
* <p>The default implementation simply tries to resubmit the form with a new form object.
* This should also work if the user hit the back button, changed some form data,
* and resubmitted the form.
* <p>Note: To avoid duplicate submissions, you need to override this method.
* Either show some "invalid submit" message, or call <code>showNewForm</code> for
* resetting the form (prepopulating it with the current values if "bindOnNewForm"
* is true). In this case, the form object in the session serves as transaction token.
* <pre class="code">
* protected ModelAndView renderInvalidSubmit(RenderRequest request, RenderResponse response) throws Exception {
* return showNewForm(request, response);
* }</pre>
* You can also show a new form but with special errors registered on it:
* <pre class="code">
* protected ModelAndView renderInvalidSubmit(RenderRequest request, RenderResponse response) throws Exception {
* BindException errors = getErrorsForNewForm(request);
* errors.reject("duplicateFormSubmission", "Duplicate form submission");
* return showForm(request, response, errors);
* }</pre>
* <p><b>WARNING:</b> If you override this method, be sure to also override the action
* phase version of this method so that it will not attempt to perform the resubmit
* action by default.
* @param request current render request
* @param response current render response
* @return a prepared view, or null if handled directly
* @throws Exception in case of errors
* @see #handleInvalidSubmit
*/
protected ModelAndView renderInvalidSubmit(RenderRequest request, RenderResponse response)
throws Exception {
return renderFormSubmission(request, response, getRenderCommand(request), getRenderErrors(request));
}
/**
* Handle an invalid submit request, e.g. when in session form mode but no form object
* was found in the session (like in case of an invalid resubmit by the browser).
* <p>The default implementation simply tries to resubmit the form with a new form object.
* This should also work if the user hit the back button, changed some form data,
* and resubmitted the form.
* <p>Note: To avoid duplicate submissions, you need to override this method.
* Most likely you will simply want it to do nothing here in the action phase
* and diplay an appropriate error and a new form in the render phase.
* <pre class="code">
* protected void handleInvalidSubmit(ActionRequest request, ActionResponse response) throws Exception {
* }</pre>
* <p>If you override this method but you do need a command object and bind errors
* in the render phase, be sure to call {@link #setRenderCommandAndErrors setRenderCommandAndErrors}
* from here.
* @param request current action request
* @param response current action response
* @throws Exception in case of errors
* @see #renderInvalidSubmit
* @see #setRenderCommandAndErrors
*/
protected void handleInvalidSubmit(ActionRequest request, ActionResponse response) throws Exception {
passRenderParameters(request, response);
Object command = formBackingObject(request);
if (command == null) {
throw new PortletException("Form object returned by formBackingObject() must not be null");
}
if (!checkCommand(command)) {
throw new PortletException("Form object returned by formBackingObject() must match commandClass");
}
PortletRequestDataBinder binder = bindAndValidate(request, command);
BindException errors = new BindException(binder.getBindingResult());
processFormSubmission(request, response, command, errors);
setRenderCommandAndErrors(request, command, errors);
}
}
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