    001// Licensed under the Apache License, Version 2.0 (the "License");
    002// you may not use this file except in compliance with the License.
    003// You may obtain a copy of the License at
    004//
    005// http://www.apache.org/licenses/LICENSE-2.0
    006//
    007// Unless required by applicable law or agreed to in writing, software
    008// distributed under the License is distributed on an "AS IS" BASIS,
    009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    010// See the License for the specific language governing permissions and
    011// limitations under the License.
    012
    013package org.apache.tapestry5.corelib.components;
    014
    015import org.apache.tapestry5.*;
    016import org.apache.tapestry5.annotations.*;
    017import org.apache.tapestry5.beanmodel.services.*;
    018import org.apache.tapestry5.commons.Location;
    019import org.apache.tapestry5.commons.Messages;
    020import org.apache.tapestry5.commons.internal.util.TapestryException;
    021import org.apache.tapestry5.commons.services.PropertyAccess;
    022import org.apache.tapestry5.commons.util.ExceptionUtils;
    023import org.apache.tapestry5.corelib.ClientValidation;
    024import org.apache.tapestry5.corelib.internal.ComponentActionSink;
    025import org.apache.tapestry5.corelib.internal.FormSupportImpl;
    026import org.apache.tapestry5.corelib.internal.InternalFormSupport;
    027import org.apache.tapestry5.dom.Element;
    028import org.apache.tapestry5.http.Link;
    029import org.apache.tapestry5.http.services.Request;
    030import org.apache.tapestry5.internal.BeanValidationContext;
    031import org.apache.tapestry5.internal.BeanValidationContextImpl;
    032import org.apache.tapestry5.internal.InternalConstants;
    033import org.apache.tapestry5.internal.services.FormControlNameManager;
    034import org.apache.tapestry5.internal.services.HeartbeatImpl;
    035import org.apache.tapestry5.internal.util.AutofocusValidationDecorator;
    036import org.apache.tapestry5.ioc.annotations.Inject;
    037import org.apache.tapestry5.ioc.annotations.Symbol;
    038import org.apache.tapestry5.ioc.internal.util.InternalUtils;
    039import org.apache.tapestry5.ioc.util.IdAllocator;
    040import org.apache.tapestry5.json.JSONArray;
    041import org.apache.tapestry5.runtime.Component;
    042import org.apache.tapestry5.services.ClientDataEncoder;
    043import org.apache.tapestry5.services.ComponentSource;
    044import org.apache.tapestry5.services.Environment;
    045import org.apache.tapestry5.services.FormSupport;
    046import org.apache.tapestry5.services.Heartbeat;
    047import org.apache.tapestry5.services.StreamPageContent;
    048import org.apache.tapestry5.services.compatibility.DeprecationWarning;
    049import org.apache.tapestry5.services.javascript.JavaScriptSupport;
    050import org.slf4j.Logger;
    051
    052import java.io.EOFException;
    053import java.io.IOException;
    054import java.io.ObjectInputStream;
    055import java.io.UnsupportedEncodingException;
    056import java.net.URLDecoder;
    057
    058/**
    059 * An HTML form, which will enclose other components to render out the various
    060 * types of fields.
    061 *
    062 * A Form triggers many notification events. When it renders, it triggers a
    063 * {@link org.apache.tapestry5.EventConstants#PREPARE_FOR_RENDER} notification, followed by a
    064 * {@link EventConstants#PREPARE} notification.
    065 *
    066 * When the form is submitted, the component triggers several notifications: first a
    067 * {@link EventConstants#PREPARE_FOR_SUBMIT}, then a {@link EventConstants#PREPARE}: these allow the page to update its
    068 * state as necessary to prepare for the form submission.
    069 *
    070 * The Form component then determines if the form was cancelled (see {@link org.apache.tapestry5.corelib.SubmitMode#CANCEL}). If so,
    071 * a {@link EventConstants#CANCELED} event is triggered.
    072 *
    073 * Next come notifications to contained components (or more accurately, the execution of stored {@link ComponentAction}s), to allow each component to retrieve and validate
    074 * submitted values, and update server-side properties.  This is based on the {@code t:formdata} query parameter,
    075 * which contains serialized object data (generated when the form initially renders).
    076 *
    077 * Once the form data is processed, the next step is to trigger the
    078 * {@link EventConstants#VALIDATE}, which allows for cross-form validation. After that, either a
    079 * {@link EventConstants#SUCCESS} OR {@link EventConstants#FAILURE} event (depending on whether the
    080 * {@link ValidationTracker} has recorded any errors). Lastly, a {@link EventConstants#SUBMIT} event, for any listeners
    081 * that care only about form submission, regardless of success or failure.
    082 *
    083 * For all of these notifications, the event context is derived from the <strong>context</strong> component parameter. This
    084 * context is encoded into the form's action URI (the parameter is not read when the form is submitted, instead the
    085 * values encoded into the form are used).
    086 *
    087 *
    088 * While rendering, or processing a Form submission, the Form component places a {@link FormSupport} object into the {@linkplain Environment environment},
    089 * so that enclosed components can coordinate with the Form component. It also places a {@link ValidationTracker} into the environment during both render and submission.
    090 * During submission it also pushes a {@link Heartbeat} into the environment, which is {@link org.apache.tapestry5.services.Heartbeat#end() ended} just before
    091 * {@linkplain FormSupport#defer(Runnable) deferred FormSupport operations} are executed.
    092 *
    093 *
    094 * @tapestrydoc
    095 * @see BeanEditForm
    096 * @see Errors
    097 * @see FormFragment
    098 * @see Label
    099 */
    100@Events(
    101        {EventConstants.PREPARE_FOR_RENDER, EventConstants.PREPARE, EventConstants.PREPARE_FOR_SUBMIT,
    102                EventConstants.VALIDATE, EventConstants.SUBMIT, EventConstants.FAILURE, EventConstants.SUCCESS, EventConstants.CANCELED})
    103@SupportsInformalParameters
    104public class Form implements ClientElement, FormValidationControl
    105{
    106    /**
    107     * Query parameter name storing form data (the serialized commands needed to
    108     * process a form submission).
    109     */
    110    public static final String FORM_DATA = "t:formdata";
    111
    112    /**
    113     * Used by {@link Submit}, etc., to identify which particular client-side element (by element id)
    114     * was responsible for the submission. An empty hidden field is created, as needed, to store this value.
    115     * Starting in Tapestry 5.3, this is a JSONArray with two values: the client id followed by the client name.
    116     *
    117     * @since 5.2.0
    118     */
    119    public static final String SUBMITTING_ELEMENT_ID = "t:submit";
    120
    121    public static final StreamPageContent STREAM_ACTIVE_PAGE_CONTENT = new StreamPageContent().withoutActivation();
    122
    123    /**
    124     * The context for the link (optional parameter). This list of values will
    125     * be converted into strings and included in
    126     * the URI. The strings will be coerced back to whatever their values are
    127     * and made available to event handler
    128     * methods.
    129     */
    130    @Parameter
    131    private Object[] context;
    132
    133    /**
    134     * The object which will record user input and validation errors. When not using
    135     * the default behavior supplied by the Form component (an immediate re-render of the active
    136     * page when there are form validation errors), it is necessary to bind this parameter
    137     * to a persistent value that can be maintained until the active page is re-rendered. See
    138     * <a href="https://issues.apache.org/jira/browse/TAP5-1808">TAP5-1801</a>.
    139     */
    140    @Parameter("defaultTracker")
    141    protected ValidationTracker tracker;
    142
    143    @Inject
    144    @Symbol(SymbolConstants.FORM_CLIENT_LOGIC_ENABLED)
    145    private boolean clientLogicDefaultEnabled;
    146
    147    /**
    148     * Controls when client validation occurs on the client, if at all. Defaults to {@link ClientValidation#SUBMIT}.
    149     * {@link ClientValidation#BLUR} was the default, prior to Tapestry 5.4, but is no longer supported.
    150     */
    151    @Parameter(allowNull = false, defaultPrefix = BindingConstants.LITERAL)
    152    private ClientValidation clientValidation = clientLogicDefaultEnabled ? ClientValidation.SUBMIT
    153            : ClientValidation.NONE;
    154
    155    /**
    156     * If true (the default), then the JavaScript will be added to position the
    157     * cursor into the form. The field to
    158     * receive focus is the first rendered field that is in error, or required,
    159     * or present (in that order of priority).
    160     *
    161     * @see SymbolConstants#FORM_CLIENT_LOGIC_ENABLED
    162     */
    163    @Parameter
    164    private boolean autofocus = clientLogicDefaultEnabled;
    165
    166    /**
    167     * Binding the zone parameter will cause the form submission to be handled
    168     * as an Ajax request that updates the
    169     * indicated zone. Often a Form will update the same zone that contains it.
    170     */
    171    @Parameter(defaultPrefix = BindingConstants.LITERAL)
    172    private String zone;
    173
    174    /**
    175     * If true, then the Form's action will be secure (using an absolute URL with the HTTPs scheme) regardless
    176     * of whether the containing page itself is secure or not. This parameter does nothing
    177     * when {@linkplain SymbolConstants#SECURE_ENABLED security is disabled} (which is often
    178     * the case in development mode). This only affects how the Form's action attribute is rendered, there is
    179     * not (currently) a check that the form is actually submitted securely.
    180     */
    181    @Parameter
    182    private boolean secure;
    183
    184    /**
    185     * Prefix value used when searching for validation messages and constraints.
    186     * The default is the Form component's
    187     * id. This is overridden by {@link org.apache.tapestry5.corelib.components.BeanEditForm}.
    188     *
    189     * @see org.apache.tapestry5.services.FormSupport#getFormValidationId()
    190     */
    191    @Parameter
    192    private String validationId;
    193
    194    /**
    195     * Object to validate during the form submission process. The default is the Form component's container.
    196     * This parameter should only be used in combination with the Bean Validation Library.
    197     */
    198    @Parameter
    199    private Object validate;
    200
    201    /**
    202     * When true, the the form will submit as an asynchronous request (via XmlHttpRequest); the event handler methods
    203     * can make use of the {@link org.apache.tapestry5.services.ajax.AjaxResponseRenderer} in order to force content
    204     * updates to the client.  This is used as an alternative to placing the form inside a {@link org.apache.tapestry5.corelib.components.Zone}
    205     * and binding the {@code zone} parameter.
    206     *
    207     * @since 5.4
    208     */
    209    @Parameter
    210    private boolean async = false;
    211
    212    @Inject
    213    private Logger logger;
    214
    215    @Inject
    216    private Environment environment;
    217
    218    @Inject
    219    private ComponentResources resources;
    220
    221    @Inject
    222    private Messages messages;
    223
    224    @Environmental
    225    private JavaScriptSupport javascriptSupport;
    226
    227    @Inject
    228    private Request request;
    229
    230    @Inject
    231    private ComponentSource source;
    232
    233    @Inject
    234    private FormControlNameManager formControlNameManager;
    235
    236
    237    /**
    238     * Starting in 5.4, this is a simple, non-persistent property, with no extra magic tricks.
    239     */
    240    private ValidationTracker defaultTracker;
    241
    242    @Inject
    243    @Symbol(SymbolConstants.SECURE_ENABLED)
    244    private boolean secureEnabled;
    245
    246    private InternalFormSupport formSupport;
    247
    248    private Element form;
    249
    250    private Element div;
    251
    252    // Collects a stream of component actions. Each action goes in as a UTF
    253    // string (the component
    254    // component id), followed by a ComponentAction
    255
    256    private ComponentActionSink actionSink;
    257
    258    @SuppressWarnings("unchecked")
    259    @Environmental
    260    private TrackableComponentEventCallback eventCallback;
    261
    262    @Inject
    263    private ClientDataEncoder clientDataEncoder;
    264
    265    @Inject
    266    private PropertyAccess propertyAccess;
    267
    268    @Inject
    269    private DeprecationWarning deprecationWarning;
    270
    271    private String clientId;
    272
    273    @Inject
    274    private ComponentSource componentSource;
    275
    276    String defaultValidationId()
    277    {
    278        return resources.getId();
    279    }
    280
    281    Object defaultValidate()
    282    {
    283        return resources.getContainer();
    284    }
    285
    286    /**
    287     * Returns an instance of {@link ValidationTrackerImpl}, lazily creating it as needed. This property
    288     * is the default for the <strong>tracker</strong> parameter; the property (as of Tapestry 5.4) is not
    289     * persistent.
    290     *
    291     * @return per-request cached instance
    292     */
    293    public ValidationTracker getDefaultTracker()
    294    {
    295        if (defaultTracker == null)
    296        {
    297            defaultTracker = new ValidationTrackerImpl();
    298        }
    299
    300        return defaultTracker;
    301    }
    302
    303    /**
    304     * @deprecated In 5.4; previously used only for testing
    305     */
    306    public void setDefaultTracker(ValidationTracker defaultTracker)
    307    {
    308        this.defaultTracker = defaultTracker;
    309    }
    310
    311    void setupRender()
    312    {
    313        FormSupport existing = environment.peek(FormSupport.class);
    314
    315        if (existing != null)
    316        {
    317            throw new TapestryException(messages.get("core-form-nesting-not-allowed"), existing, null);
    318        }
    319
    320        if (clientValidation == ClientValidation.BLUR)
    321        {
    322            deprecationWarning.componentParameterValue(resources, "clientValidation", clientValidation, "BLUR is no longer supported, starting in 5.4. Validation will occur as with SUBMIT.");
    323        }
    324    }
    325
    326    void beginRender(MarkupWriter writer)
    327    {
    328        Link link = resources.createFormEventLink(EventConstants.ACTION, context);
    329
    330        String actionURL = secure && secureEnabled ? link.toAbsoluteURI(true) : link.toURI();
    331
    332        actionSink = new ComponentActionSink(logger, clientDataEncoder);
    333
    334        clientId = javascriptSupport.allocateClientId(resources);
    335
    336        // Pre-register some names, to prevent client-side collisions with function names
    337        // attached to the JS Form object.
    338
    339        IdAllocator allocator = new IdAllocator();
    340
    341        preallocateNames(allocator);
    342
    343        formSupport = createRenderTimeFormSupport(clientId, actionSink, allocator);
    344
    345        environment.push(FormSupport.class, formSupport);
    346        environment.push(ValidationTracker.class, tracker);
    347
    348        if (autofocus)
    349        {
    350            ValidationDecorator autofocusDecorator = new AutofocusValidationDecorator(
    351                    environment.peek(ValidationDecorator.class), tracker, javascriptSupport);
    352            environment.push(ValidationDecorator.class, autofocusDecorator);
    353        }
    354
    355        // Now that the environment is setup, inform the component or other
    356        // listeners that the form
    357        // is about to render.
    358
    359        resources.triggerEvent(EventConstants.PREPARE_FOR_RENDER, context, null);
    360
    361        resources.triggerEvent(EventConstants.PREPARE, context, null);
    362
    363        // Push BeanValidationContext only after the container had a chance to prepare
    364        environment.push(BeanValidationContext.class, new BeanValidationContextImpl(validate));
    365
    366        // Save the form element for later, in case we want to write an encoding
    367        // type attribute.
    368
    369        form = writer.element("form",
    370                "id", clientId,
    371                "method", "post",
    372                "action", actionURL,
    373                "data-update-zone", zone);
    374
    375        if (clientValidation != ClientValidation.NONE)
    376        {
    377            writer.attributes("data-validate", "submit");
    378        }
    379
    380        if (async)
    381        {
    382            javascriptSupport.require("t5/core/zone");
    383            writer.attributes("data-async-trigger", true);
    384        }
    385
    386        resources.renderInformalParameters(writer);
    387
    388        div = writer.element("div");
    389
    390        for (String parameterName : link.getParameterNames())
    391        {
    392            String[] values = link.getParameterValues(parameterName);
    393
    394            for (String value : values)
    395            {
    396                // The parameter value is expected to be encoded,
    397                // but the input value shouldn't be encoded.
    398                try
    399                {
    400                    value = URLDecoder.decode(value, "UTF-8");
    401                } catch (UnsupportedEncodingException e)
    402                {
    403                    logger.error("Enable to decode parameter value for parameter {} in form {}",
    404                            parameterName, form.getName(), e);
    405                }
    406                writer.element("input", "type", "hidden", "name", parameterName, "value", value);
    407                writer.end();
    408            }
    409        }
    410
    411        writer.end(); // div
    412
    413        environment.peek(Heartbeat.class).begin();
    414    }
    415
    416    /**
    417     * Creates an {@link org.apache.tapestry5.corelib.internal.InternalFormSupport} for
    418     * this Form.
    419     *
    420     * This method may also be invoked as the handler for the "internalCreateRenderTimeFormSupport" event.
    421     *
    422     * @param clientId
    423     *         the client-side id for the rendered form
    424     *         element
    425     * @param actionSink
    426     *         used to collect component actions that will, ultimately, be
    427     *         written as the t:formdata hidden
    428     *         field
    429     * @param allocator
    430     *         used to allocate unique ids
    431     * @return form support object
    432     */
    433    @OnEvent("internalCreateRenderTimeFormSupport")
    434    InternalFormSupport createRenderTimeFormSupport(String clientId, ComponentActionSink actionSink,
    435                                                    IdAllocator allocator)
    436    {
    437        return new FormSupportImpl(resources, clientId, actionSink,
    438                clientValidation != ClientValidation.NONE, allocator, validationId);
    439    }
    440
    441    void afterRender(MarkupWriter writer)
    442    {
    443        environment.peek(Heartbeat.class).end();
    444
    445        formSupport.executeDeferred();
    446
    447        String encodingType = formSupport.getEncodingType();
    448
    449        if (encodingType != null)
    450        {
    451            form.forceAttributes("enctype", encodingType);
    452        }
    453
    454        writer.end(); // form
    455
    456        div.element("input", "type", "hidden", "name", FORM_DATA, "value", actionSink.getClientData());
    457        div.pop();
    458
    459        if (autofocus)
    460        {
    461            environment.pop(ValidationDecorator.class);
    462        }
    463    }
    464
    465    void cleanupRender()
    466    {
    467        environment.pop(FormSupport.class);
    468
    469        formSupport = null;
    470
    471        environment.pop(ValidationTracker.class);
    472
    473        tracker.clear();
    474
    475        environment.pop(BeanValidationContext.class);
    476    }
    477
    478    @SuppressWarnings(
    479            {"unchecked", "InfiniteLoopStatement"})
    480    Object onAction(EventContext context) throws IOException
    481    {
    482        beforeProcessSubmit(context);
    483
    484        tracker.clear();
    485
    486        formSupport = new FormSupportImpl(resources, validationId);
    487
    488        environment.push(ValidationTracker.class, tracker);
    489        environment.push(FormSupport.class, formSupport);
    490
    491        Heartbeat heartbeat = new HeartbeatImpl();
    492
    493        environment.push(Heartbeat.class, heartbeat);
    494
    495        heartbeat.begin();
    496
    497        boolean didPushBeanValidationContext = false;
    498
    499        try
    500        {
    501            resources.triggerContextEvent(EventConstants.PREPARE_FOR_SUBMIT, context, eventCallback);
    502
    503            if (eventCallback.isAborted())
    504                return true;
    505
    506            resources.triggerContextEvent(EventConstants.PREPARE, context, eventCallback);
    507            if (eventCallback.isAborted())
    508                return true;
    509
    510            if (isFormCancelled())
    511            {
    512                executeStoredActions(true);
    513
    514                resources.triggerContextEvent(EventConstants.CANCELED, context, eventCallback);
    515                if (eventCallback.isAborted())
    516                    return true;
    517            }
    518
    519            environment.push(BeanValidationContext.class, new BeanValidationContextImpl(validate));
    520
    521            didPushBeanValidationContext = true;
    522
    523            executeStoredActions(false);
    524
    525            heartbeat.end();
    526
    527            formSupport.executeDeferred();
    528
    529            fireValidateEvent(EventConstants.VALIDATE, context, eventCallback);
    530
    531            if (eventCallback.isAborted())
    532            {
    533                return true;
    534            }
    535
    536            afterValidate();
    537
    538            // Let the listeners know about overall success or failure. Most
    539            // listeners fall into
    540            // one of those two camps.
    541
    542            // If the tracker has no errors, then clear it of any input values
    543            // as well, so that the next page render will be "clean" and show
    544            // true persistent data, not value from the previous form
    545            // submission.
    546
    547            if (!tracker.getHasErrors())
    548            {
    549                tracker.clear();
    550            }
    551
    552            String eventType = tracker.getHasErrors()
    553                    ? EventConstants.FAILURE
    554                    : EventConstants.SUCCESS;
    555
    556            resources.triggerContextEvent(eventType, context, eventCallback);
    557
    558            if (eventCallback.isAborted())
    559            {
    560                return true;
    561            }
    562
    563            // Lastly, tell anyone whose interested that the form is completely
    564            // submitted.
    565
    566            resources.triggerContextEvent(EventConstants.SUBMIT, context, eventCallback);
    567
    568            afterSuccessOrFailure();
    569
    570            if (eventCallback.isAborted())
    571            {
    572                return true;
    573            }
    574
    575            // For traditional request with no validation exceptions, re-render the
    576            // current page immediately, as-is.  Prior to Tapestry 5.4, a redirect was
    577            // sent that required that the tracker be persisted across requests.
    578            // See https://issues.apache.org/jira/browse/TAP5-1808
    579
    580            if (tracker.getHasErrors() && !request.isXHR())
    581            {
    582                return STREAM_ACTIVE_PAGE_CONTENT;
    583            }
    584
    585            // The event will not work its way up.
    586
    587            return false;
    588
    589        } finally
    590        {
    591            environment.pop(Heartbeat.class);
    592            environment.pop(FormSupport.class);
    593
    594            environment.pop(ValidationTracker.class);
    595
    596            if (didPushBeanValidationContext)
    597            {
    598                environment.pop(BeanValidationContext.class);
    599            }
    600        }
    601    }
    602
    603    /**
    604     * A hook invoked from {@link #onAction(org.apache.tapestry5.EventContext)} after the
    605     * {@link org.apache.tapestry5.EventConstants#SUBMIT} or {@link org.apache.tapestry5.EventConstants#FAILURE} event has been triggered.
    606     *
    607     * This method will be invoked regardless of whether the submit or failure event was aborted.
    608     *
    609     * This implementation does nothing.
    610     *
    611     * @since 5.4
    612     */
    613
    614    protected void afterSuccessOrFailure()
    615    {
    616
    617    }
    618
    619    /**
    620     * A hook invoked from {@link #onAction(org.apache.tapestry5.EventContext)} before any other setup.
    621     *
    622     * This implementation does nothing.
    623     *
    624     * @param context
    625     *         as passed to {@code onAction()}
    626     * @since 5.4
    627     */
    628    protected void beforeProcessSubmit(EventContext context)
    629    {
    630
    631    }
    632
    633    /**
    634     * A hook invoked from {@link #onAction(org.apache.tapestry5.EventContext)} after the
    635     * {@link org.apache.tapestry5.EventConstants#VALIDATE} event has been triggered, and
    636     * before the {@link #tracker} has been {@linkplain org.apache.tapestry5.ValidationTracker#clear() cleared}.
    637     *
    638     * Only invoked if the valiate event did not abort (that is, the no event handler method returned a value).
    639     *
    640     * This implementation does nothing.
    641     *
    642     * @since 5.4
    643     */
    644    protected void afterValidate()
    645    {
    646
    647    }
    648
    649    private boolean isFormCancelled()
    650    {
    651        // The "cancel" query parameter is reserved for this purpose; if it is present then the form was canceled on the
    652        // client side.  For image submits, there will be two parameters: "cancel.x" and "cancel.y".
    653
    654        if (request.getParameter(InternalConstants.CANCEL_NAME) != null ||
    655                request.getParameter(InternalConstants.CANCEL_NAME + ".x") != null)
    656        {
    657            return true;
    658        }
    659
    660        // When JavaScript is involved, it's more complicated. In fact, this is part of HLS's desire
    661        // to have all forms submit via XHR when JavaScript is present, since it would provide
    662        // an opportunity to get the submitting element's value into the request properly.
    663
    664        String raw = request.getParameter(SUBMITTING_ELEMENT_ID);
    665
    666        if (InternalUtils.isNonBlank(raw) &&
    667                new JSONArray(raw).getString(1).equals(InternalConstants.CANCEL_NAME))
    668        {
    669            return true;
    670        }
    671
    672        return false;
    673    }
    674
    675
    676    private void fireValidateEvent(String eventName, EventContext context, TrackableComponentEventCallback callback)
    677    {
    678        try
    679        {
    680            resources.triggerContextEvent(eventName, context, callback);
    681        } catch (RuntimeException ex)
    682        {
    683            ValidationException ve = ExceptionUtils.findCause(ex, ValidationException.class, propertyAccess);
    684
    685            if (ve != null)
    686            {
    687                ValidationTracker tracker = environment.peek(ValidationTracker.class);
    688
    689                tracker.recordError(ve.getMessage());
    690
    691                return;
    692            }
    693
    694            throw ex;
    695        }
    696    }
    697
    698    /**
    699     * Pulls the stored actions out of the request, converts them from MIME
    700     * stream back to object stream and then
    701     * objects, and executes them.
    702     */
    703    private void executeStoredActions(boolean forFormCancel)
    704    {
    705        String[] values = request.getParameters(FORM_DATA);
    706
    707        if (!request.getMethod().equals("POST") || values == null)
    708            throw new RuntimeException(messages.format("core-invalid-form-request", FORM_DATA));
    709
    710        // Due to Ajax there may be multiple values here, so
    711        // handle each one individually.
    712
    713        for (String clientEncodedActions : values)
    714        {
    715            if (InternalUtils.isBlank(clientEncodedActions))
    716                continue;
    717
    718            logger.debug("Processing actions: {}", clientEncodedActions);
    719
    720            ObjectInputStream ois = null;
    721
    722            Component component = null;
    723
    724            try
    725            {
    726                ois = clientDataEncoder.decodeClientData(clientEncodedActions);
    727
    728                while (!eventCallback.isAborted())
    729                {
    730                    String componentId = ois.readUTF();
    731                    boolean cancelAction = ois.readBoolean();
    732                    ComponentAction action = (ComponentAction) ois.readObject();
    733
    734                    // Actions are a mix of ordinary actions and cancel actions.  Filter out one set or the other
    735                    // based on whether the form was submitted or cancelled.
    736                    if (forFormCancel != cancelAction)
    737                    {
    738                        continue;
    739                    }
    740
    741                    component = source.getComponent(componentId);
    742
    743                    logger.debug("Processing: {} {}", componentId, action);
    744
    745                    action.execute(component);
    746
    747                    component = null;
    748                }
    749            } catch (EOFException ex)
    750            {
    751                // Expected
    752            } catch (Exception ex)
    753            {
    754                Location location = component == null ? null : component.getComponentResources().getLocation();
    755
    756                throw new TapestryException(ex.getMessage(), location, ex);
    757            } finally
    758            {
    759                InternalUtils.close(ois);
    760            }
    761        }
    762    }
    763
    764    public void recordError(String errorMessage)
    765    {
    766        tracker.recordError(errorMessage);
    767    }
    768
    769    public void recordError(Field field, String errorMessage)
    770    {
    771        tracker.recordError(field, errorMessage);
    772    }
    773
    774    public boolean getHasErrors()
    775    {
    776        return tracker.getHasErrors();
    777    }
    778
    779    public boolean isValid()
    780    {
    781        return !tracker.getHasErrors();
    782    }
    783
    784    public void clearErrors()
    785    {
    786        tracker.clear();
    787    }
    788
    789    // For testing:
    790
    791    void setTracker(ValidationTracker tracker)
    792    {
    793        this.tracker = tracker;
    794    }
    795
    796    /**
    797     * Forms use the same value for their name and their id attribute.
    798     */
    799    public String getClientId()
    800    {
    801        return clientId;
    802    }
    803
    804    private void preallocateNames(IdAllocator idAllocator)
    805    {
    806        for (String name : formControlNameManager.getReservedNames())
    807        {
    808            idAllocator.allocateId(name);
    809            // See https://issues.apache.org/jira/browse/TAP5-1632
    810            javascriptSupport.allocateClientId(name);
    811
    812        }
    813
    814        Component activePage = componentSource.getActivePage();
    815
    816        // This is unlikely but may be possible if people override some of the standard
    817        // exception reporting logic.
    818
    819        if (activePage == null)
    820            return;
    821
    822        ComponentResources activePageResources = activePage.getComponentResources();
    823
    824        try
    825        {
    826
    827            activePageResources.triggerEvent(EventConstants.PREALLOCATE_FORM_CONTROL_NAMES, new Object[]
    828                    {idAllocator}, null);
    829        } catch (RuntimeException ex)
    830        {
    831            logger.error(
    832                    String.format("Unable to obtain form control names to preallocate: %s",
    833                            ExceptionUtils.toMessage(ex)), ex);
    834        }
    835    }
    836}