/*
* Copyright 2002-2007 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.servlet.mvc;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.validation.BindException;
import org.springframework.validation.Errors;
import org.springframework.web.servlet.ModelAndView;
/**
* <p>Concrete FormController implementation that provides configurable
* form and success views, and an onSubmit chain for convenient overriding.
* Automatically resubmits to the form view in case of validation errors,
* and renders the success view in case of a valid submission.</p>
*
* <p>The workflow of this Controller does not differ much from the one described
* in the {@link AbstractFormController AbstractFormController}. The difference
* is that you do not need to implement {@link #showForm showForm} and
* {@link #processFormSubmission processFormSubmission}: A form view and a
* success view can be configured declaratively.</p>
*
* <p><b><a name="workflow">Workflow
* (<a href="AbstractFormController.html#workflow">in addition to the superclass</a>):</b><br>
* <ol>
* <li>Call to {@link #processFormSubmission processFormSubmission} which inspects
* the {@link org.springframework.validation.Errors Errors} object to see if
* any errors have occurred during binding and validation.</li>
* <li>If errors occured, the controller will return the configured formView,
* showing the form again (possibly rendering according error messages).</li>
* <li>If {@link #isFormChangeRequest isFormChangeRequest} is overridden and returns
* true for the given request, the controller will return the formView too.
* In that case, the controller will also suppress validation. Before returning the formView,
* the controller will invoke {@link #onFormChange}, giving sub-classes a chance
* to make modification to the command object.
* This is intended for requests that change the structure of the form,
* which should not cause validation and show the form in any case.</li>
* <li>If no errors occurred, the controller will call
* {@link #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException) onSubmit}
* using all parameters, which in case of the default implementation delegates to
* {@link #onSubmit(Object, BindException) onSubmit} with just the command object.
* The default implementation of the latter method will return the configured
* <code>successView</code>. Consider implementing {@link #doSubmitAction} doSubmitAction
* for simply performing a submit action and rendering the success view.</li>
* </ol>
* </p>
*
* <p>The submit behavior can be customized by overriding one of the
* {@link #onSubmit onSubmit} methods. Submit actions can also perform
* custom validation if necessary (typically database-driven checks), calling
* {@link #showForm(HttpServletRequest, HttpServletResponse, BindException) showForm}
* in case of validation errors to show the form view again.</p>
*
* <p><b><a name="config">Exposed configuration properties</a>
* (<a href="AbstractFormController.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>formView</td>
* <td><i>null</i></td>
* <td>Indicates what view to use when the user asks for a new form
* or when validation errors have occurred on form submission.</td>
* </tr>
* <tr>
* <td>successView</td>
* <td><i>null</i></td>
* <td>Indicates what view to use when successful form submissions have
* occurred. Such a success view could e.g. display a submission summary.
* More sophisticated actions can be implemented by overriding one of
* the {@link #onSubmit(Object) onSubmit()} methods.</td>
* </tr>
* <table>
* </p>
*
* @author Juergen Hoeller
* @author Rob Harrop
* @since 05.05.2003
*/
public class SimpleFormController extends AbstractFormController {
private String formView;
private String successView;
/**
* Create a new SimpleFormController.
* <p>Subclasses should set the following properties, either in the constructor
* or via a BeanFactory: commandName, commandClass, sessionForm, formView,
* successView. Note that commandClass doesn't need to be set when overriding
* <code>formBackingObject</code>, as this determines the class anyway.
* @see #setCommandClass
* @see #setCommandName
* @see #setSessionForm
* @see #setFormView
* @see #setSuccessView
* @see #formBackingObject
*/
public SimpleFormController() {
// AbstractFormController sets default cache seconds to 0.
super();
}
/**
* Set the name of the view that should be used for form display.
*/
public final void setFormView(String formView) {
this.formView = formView;
}
/**
* Return the name of the view that should be used for form display.
*/
public final String getFormView() {
return this.formView;
}
/**
* Set the name of the view that should be shown on successful submit.
*/
public final void setSuccessView(String successView) {
this.successView = successView;
}
/**
* Return the name of the view that should be shown on successful submit.
*/
public final String getSuccessView() {
return this.successView;
}
/**
* This implementation shows the configured form view, delegating to the analogous
* {@link #showForm(HttpServletRequest, HttpServletResponse, BindException, Map)}
* variant with a "controlModel" argument.
* <p>Can be called within
* {@link #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException)}
* implementations, to redirect back to the form in case of custom validation errors
* (errors not determined by the validator).
* <p>Can be overridden in subclasses to show a custom view, writing directly
* to the response or preparing the response before rendering a view.
* <p>If calling showForm with a custom control model in subclasses, it's preferable
* to override the analogous showForm version with a controlModel argument
* (which will handle both standard form showing and custom form showing then).
* @see #setFormView
* @see #showForm(HttpServletRequest, HttpServletResponse, BindException, Map)
*/
protected ModelAndView showForm(
HttpServletRequest request, HttpServletResponse response, BindException errors)
throws Exception {
return showForm(request, response, errors, null);
}
/**
* This implementation shows the configured form view.
* <p>Can be called within
* {@link #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException)}
* implementations, to redirect back to the form in case of custom validation errors
* (errors not determined by the validator).
* <p>Can be overridden in subclasses to show a custom view, writing directly
* to the response or preparing the response before rendering a view.
* @param request current HTTP request
* @param errors validation errors holder
* @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 #setFormView
*/
protected ModelAndView showForm(
HttpServletRequest request, HttpServletResponse response, BindException errors, Map controlModel)
throws Exception {
return showForm(request, errors, getFormView(), controlModel);
}
/**
* Create a reference data map for the given request and command,
* consisting of bean name/bean instance pairs as expected by ModelAndView.
* <p>The default implementation delegates to {@link #referenceData(HttpServletRequest)}.
* Subclasses can override this to set reference data used in the view.
* @param request current HTTP request
* @param command form object with request parameters bound onto it
* @param errors validation errors holder
* @return a Map with reference data entries, or <code>null</code> if none
* @throws Exception in case of invalid state or arguments
* @see ModelAndView
*/
protected Map referenceData(HttpServletRequest request, Object command, Errors errors) throws Exception {
return referenceData(request);
}
/**
* Create a reference data map for the given request.
* Called by the {@link #referenceData(HttpServletRequest, Object, Errors)}
* variant with all parameters.
* <p>The default implementation returns <code>null</code>.
* Subclasses can override this to set reference data used in the view.
* @param request current HTTP request
* @return a Map with reference data entries, or <code>null</code> if none
* @throws Exception in case of invalid state or arguments
* @see #referenceData(HttpServletRequest, Object, Errors)
* @see ModelAndView
*/
protected Map referenceData(HttpServletRequest request) throws Exception {
return null;
}
/**
* This implementation calls
* {@link #showForm(HttpServletRequest, HttpServletResponse, BindException)}
* in case of errors, and delegates to the full
* {@link #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException)}'s
* variant else.
* <p>This can only be overridden to check for an action that should be executed
* without respect to binding errors, like a cancel action. To just handle successful
* submissions without binding errors, override one of the <code>onSubmit</code>
* methods or {@link #doSubmitAction}.
* @see #showForm(HttpServletRequest, HttpServletResponse, BindException)
* @see #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException)
* @see #onSubmit(Object, BindException)
* @see #onSubmit(Object)
* @see #doSubmitAction(Object)
*/
protected ModelAndView processFormSubmission(
HttpServletRequest request, HttpServletResponse response, Object command, BindException errors)
throws Exception {
if (errors.hasErrors()) {
if (logger.isDebugEnabled()) {
logger.debug("Data binding errors: " + errors.getErrorCount());
}
return showForm(request, response, errors);
}
else if (isFormChangeRequest(request, command)) {
logger.debug("Detected form change request -> routing request to onFormChange");
onFormChange(request, response, command, errors);
return showForm(request, response, errors);
}
else {
logger.debug("No errors -> processing submit");
return onSubmit(request, response, command, errors);
}
}
/**
* This implementation delegates to {@link #isFormChangeRequest(HttpServletRequest, Object)}:
* A form change request changes the appearance of the form and should not get
* validated but just show the new form.
* @see #isFormChangeRequest
*/
protected boolean suppressValidation(HttpServletRequest request, Object command) {
return isFormChangeRequest(request, command);
}
/**
* Determine whether the given request is a form change request.
* A form change request changes the appearance of the form
* and should always show the new form, without validation.
* <p>Gets called by {@link #suppressValidation} and {@link #processFormSubmission}.
* Consequently, this single method determines to suppress validation
* <i>and</i> to show the form view in any case.
* <p>The default implementation delegates to
* {@link #isFormChangeRequest(javax.servlet.http.HttpServletRequest)}.
* @param request current HTTP request
* @param command form object with request parameters bound onto it
* @return whether the given request is a form change request
* @see #suppressValidation
* @see #processFormSubmission
*/
protected boolean isFormChangeRequest(HttpServletRequest request, Object command) {
return isFormChangeRequest(request);
}
/**
* Simpler <code>isFormChangeRequest</code> variant, called by the full
* variant {@link #isFormChangeRequest(HttpServletRequest, Object)}.
* <p>The default implementation returns <code>false</code.
* @param request current HTTP request
* @return whether the given request is a form change request
* @see #suppressValidation
* @see #processFormSubmission
*/
protected boolean isFormChangeRequest(HttpServletRequest request) {
return false;
}
/**
* Called during form submission if
* {@link #isFormChangeRequest(javax.servlet.http.HttpServletRequest)}
* returns <code>true</code>. Allows subclasses to implement custom logic
* to modify the command object to directly modify data in the form.
* <p>The default implementation delegates to
* {@link #onFormChange(HttpServletRequest, HttpServletResponse, Object, BindException)}.
* @param request current servlet request
* @param response current servlet response
* @param command form object with request parameters bound onto it
* @param errors validation errors holder, allowing for additional
* custom validation
* @throws Exception in case of errors
* @see #isFormChangeRequest(HttpServletRequest)
* @see #onFormChange(HttpServletRequest, HttpServletResponse, Object)
*/
protected void onFormChange(
HttpServletRequest request, HttpServletResponse response, Object command, BindException errors)
throws Exception {
onFormChange(request, response, command);
}
/**
* Simpler <code>onFormChange</code> variant, called by the full variant
* {@link #onFormChange(HttpServletRequest, HttpServletResponse, Object, BindException)}.
* <p>The default implementation is empty.
* @param request current servlet request
* @param response current servlet response
* @param command form object with request parameters bound onto it
* @throws Exception in case of errors
* @see #onFormChange(HttpServletRequest, HttpServletResponse, Object, BindException)
*/
protected void onFormChange(HttpServletRequest request, HttpServletResponse response, Object command)
throws Exception {
}
/**
* Submit callback with all parameters. Called in case of submit without errors
* reported by the registered validator, or on every submit if no validator.
* <p>The default implementation delegates to {@link #onSubmit(Object, BindException)}.
* For simply performing a submit action and rendering the specified success
* view, consider implementing {@link #doSubmitAction} rather than an
* <code>onSubmit</code> variant.
* <p>Subclasses can override this to provide custom submission handling like storing
* the object to the database. Implementations can also perform custom validation and
* call showForm to return to the form. Do <i>not</i> implement multiple onSubmit
* methods: In that case, just this method will be called by the controller.
* <p>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.
* @param request current servlet request
* @param response current servlet response
* @param command form object with request parameters bound onto it
* @param errors Errors instance without errors (subclass can add errors if it wants to)
* @return the prepared model and view, or <code>null</code>
* @throws Exception in case of errors
* @see #onSubmit(Object, BindException)
* @see #doSubmitAction
* @see #showForm
* @see org.springframework.validation.Errors
* @see org.springframework.validation.BindException#getModel
*/
protected ModelAndView onSubmit(
HttpServletRequest request, HttpServletResponse response, Object command, BindException errors)
throws Exception {
return onSubmit(command, errors);
}
/**
* Simpler <code>onSubmit</code> variant.
* Called by the default implementation of the
* {@link #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException)}
* variant with all parameters.
* <p>The default implementation calls {@link #onSubmit(Object)}, using the
* returned ModelAndView if actually implemented in a subclass. Else, the
* default behavior will apply: rendering the success view with the command
* and Errors instance as model.
* <p>Subclasses can override this to provide custom submission handling that
* does not need request and response.
* <p>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.
* @param command form object with request parameters bound onto it
* @param errors Errors instance without errors
* @return the prepared model and view
* @throws Exception in case of errors
* @see #onSubmit(HttpServletRequest, HttpServletResponse, Object, BindException)
* @see #onSubmit(Object)
* @see #setSuccessView
* @see org.springframework.validation.Errors
* @see org.springframework.validation.BindException#getModel
*/
protected ModelAndView onSubmit(Object command, BindException errors) throws Exception {
ModelAndView mv = onSubmit(command);
if (mv != null) {
// simplest onSubmit variant implemented in custom subclass
return mv;
}
else {
// default behavior: render success view
if (getSuccessView() == null) {
throw new ServletException("successView isn't set");
}
return new ModelAndView(getSuccessView(), errors.getModel());
}
}
/**
* Simplest <code>onSubmit</code> variant. Called by the default implementation
* of the {@link #onSubmit(Object, BindException)} variant.
* <p>This implementation calls {@link #doSubmitAction(Object)} and returns
* <code>null</code> as ModelAndView, making the calling <code>onSubmit</code>
* method perform its default rendering of the success view.
* <p>Subclasses can override this to provide custom submission handling
* that just depends on the command object. It's preferable to use either
* {@link #onSubmit(Object, BindException)} or {@link #doSubmitAction(Object)},
* though: Use the former when you want to build your own ModelAndView; use the
* latter when you want to perform an action and forward to the successView.
* @param command form object with request parameters bound onto it
* @return the prepared model and view, or <code>null</code> for default
* (that is, rendering the configured "successView")
* @throws Exception in case of errors
* @see #onSubmit(Object, BindException)
* @see #doSubmitAction
* @see #setSuccessView
*/
protected ModelAndView onSubmit(Object command) throws Exception {
doSubmitAction(command);
return null;
}
/**
* Template method for submit actions. Called by the default implementation
* of the simplest {@link #onSubmit(Object)} variant.
* <p><b>This is the preferred submit callback to implement if you want to
* perform an action (like storing changes to the database) and then render
* the success view with the command and Errors instance as model.</b>
* You don't need to care about the success ModelAndView here.
* @param command form object with request parameters bound onto it
* @throws Exception in case of errors
* @see #onSubmit(Object)
* @see #setSuccessView
*/
protected void doSubmitAction(Object command) throws Exception {
}
}