001// Copyright 2006-2014 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.corelib.components;
016
017import org.apache.tapestry5.*;
018import org.apache.tapestry5.annotations.*;
019import org.apache.tapestry5.corelib.ClientValidation;
020import org.apache.tapestry5.corelib.internal.ComponentActionSink;
021import org.apache.tapestry5.corelib.internal.FormSupportImpl;
022import org.apache.tapestry5.corelib.internal.InternalFormSupport;
023import org.apache.tapestry5.dom.Element;
024import org.apache.tapestry5.internal.*;
025import org.apache.tapestry5.internal.services.HeartbeatImpl;
026import org.apache.tapestry5.internal.util.AutofocusValidationDecorator;
027import org.apache.tapestry5.ioc.Location;
028import org.apache.tapestry5.ioc.Messages;
029import org.apache.tapestry5.ioc.annotations.Inject;
030import org.apache.tapestry5.ioc.annotations.Symbol;
031import org.apache.tapestry5.ioc.internal.util.InternalUtils;
032import org.apache.tapestry5.ioc.internal.util.TapestryException;
033import org.apache.tapestry5.ioc.services.PropertyAccess;
034import org.apache.tapestry5.ioc.util.ExceptionUtils;
035import org.apache.tapestry5.ioc.util.IdAllocator;
036import org.apache.tapestry5.json.JSONArray;
037import org.apache.tapestry5.runtime.Component;
038import org.apache.tapestry5.services.*;
039import org.apache.tapestry5.services.compatibility.DeprecationWarning;
040import org.apache.tapestry5.services.javascript.JavaScriptSupport;
041import org.slf4j.Logger;
042
043import java.io.EOFException;
044import java.io.IOException;
045import java.io.ObjectInputStream;
046import java.io.UnsupportedEncodingException;
047import java.net.URLDecoder;
048
049/**
050 * An HTML form, which will enclose other components to render out the various
051 * types of fields.
052 * <p>
053 * A Form triggers many notification events. When it renders, it triggers a
054 * {@link org.apache.tapestry5.EventConstants#PREPARE_FOR_RENDER} notification, followed by a
055 * {@link EventConstants#PREPARE} notification.</p>
056 * <p>
057 * When the form is submitted, the component triggers several notifications: first a
058 * {@link EventConstants#PREPARE_FOR_SUBMIT}, then a {@link EventConstants#PREPARE}: these allow the page to update its
059 * state as necessary to prepare for the form submission.</p>
060 * <p>
061 * The Form component then determines if the form was cancelled (see {@link org.apache.tapestry5.corelib.SubmitMode#CANCEL}). If so,
062 * a {@link EventConstants#CANCELED} event is triggered.</p>
063 * <p>
064 * Next come notifications to contained components (or more accurately, the execution of stored {@link ComponentAction}s), to allow each component to retrieve and validate
065 * submitted values, and update server-side properties.  This is based on the {@code t:formdata} query parameter,
066 * which contains serialized object data (generated when the form initially renders).
067 * </p>
068 * <p>Once the form data is processed, the next step is to trigger the
069 * {@link EventConstants#VALIDATE}, which allows for cross-form validation. After that, either a
070 * {@link EventConstants#SUCCESS} OR {@link EventConstants#FAILURE} event (depending on whether the
071 * {@link ValidationTracker} has recorded any errors). Lastly, a {@link EventConstants#SUBMIT} event, for any listeners
072 * that care only about form submission, regardless of success or failure.</p>
073 * <p>
074 * For all of these notifications, the event context is derived from the <strong>context</strong> component parameter. This
075 * context is encoded into the form's action URI (the parameter is not read when the form is submitted, instead the
076 * values encoded into the form are used).
077 * </p>
078 * <p>
079 * While rendering, or processing a Form submission, the Form component places a {@link FormSupport} object into the {@linkplain Environment environment},
080 * so that enclosed components can coordinate with the Form component. It also places a {@link ValidationTracker} into the environment during both render and submission.
081 * During submission it also pushes a {@link Heartbeat} into the environment, which is {@link org.apache.tapestry5.services.Heartbeat#end() ended} just before
082 * {@linkplain FormSupport#defer(Runnable) deferred FormSupport operations} are executed.
083 * </p>
084 *
085 * @tapestrydoc
086 * @see BeanEditForm
087 * @see Errors
088 * @see FormFragment
089 * @see Label
090 */
091@Events(
092        {EventConstants.PREPARE_FOR_RENDER, EventConstants.PREPARE, EventConstants.PREPARE_FOR_SUBMIT,
093                EventConstants.VALIDATE, EventConstants.SUBMIT, EventConstants.FAILURE, EventConstants.SUCCESS, EventConstants.CANCELED})
094@SupportsInformalParameters
095public class Form implements ClientElement, FormValidationControl
096{
097    /**
098     * Query parameter name storing form data (the serialized commands needed to
099     * process a form submission).
100     */
101    public static final String FORM_DATA = "t:formdata";
102
103    /**
104     * Used by {@link Submit}, etc., to identify which particular client-side element (by element id)
105     * was responsible for the submission. An empty hidden field is created, as needed, to store this value.
106     * Starting in Tapestry 5.3, this is a JSONArray with two values: the client id followed by the client name.
107     *
108     * @since 5.2.0
109     */
110    public static final String SUBMITTING_ELEMENT_ID = "t:submit";
111
112    public static final StreamPageContent STREAM_ACTIVE_PAGE_CONTENT = new StreamPageContent().withoutActivation();
113
114    /**
115     * The context for the link (optional parameter). This list of values will
116     * be converted into strings and included in
117     * the URI. The strings will be coerced back to whatever their values are
118     * and made available to event handler
119     * methods.
120     */
121    @Parameter
122    private Object[] context;
123
124    /**
125     * The object which will record user input and validation errors. When not using
126     * the default behavior supplied by the Form component (an immediate re-render of the active
127     * page when there are form validation errors), it is necessary to bind this parameter
128     * to a persistent value that can be maintained until the active page is re-rendered. See
129     * <a href="https://issues.apache.org/jira/browse/TAP5-1808">TAP5-1801</a>.
130     */
131    @Parameter("defaultTracker")
132    private ValidationTracker tracker;
133
134    @Inject
135    @Symbol(SymbolConstants.FORM_CLIENT_LOGIC_ENABLED)
136    private boolean clientLogicDefaultEnabled;
137
138    /**
139     * Controls when client validation occurs on the client, if at all. Defaults to {@link ClientValidation#SUBMIT}.
140     * {@link ClientValidation#BLUR} was the default, prior to Tapestry 5.4, but is no longer supported.
141     */
142    @Parameter(allowNull = false, defaultPrefix = BindingConstants.LITERAL)
143    private ClientValidation clientValidation = clientLogicDefaultEnabled ? ClientValidation.SUBMIT
144            : ClientValidation.NONE;
145
146    /**
147     * If true (the default), then the JavaScript will be added to position the
148     * cursor into the form. The field to
149     * receive focus is the first rendered field that is in error, or required,
150     * or present (in that order of priority).
151     *
152     * @see SymbolConstants#FORM_CLIENT_LOGIC_ENABLED
153     */
154    @Parameter
155    private boolean autofocus = clientLogicDefaultEnabled;
156
157    /**
158     * Binding the zone parameter will cause the form submission to be handled
159     * as an Ajax request that updates the
160     * indicated zone. Often a Form will update the same zone that contains it.
161     */
162    @Parameter(defaultPrefix = BindingConstants.LITERAL)
163    private String zone;
164
165    /**
166     * If true, then the Form's action will be secure (using an absolute URL with the HTTPs scheme) regardless
167     * of whether the containing page itself is secure or not. This parameter does nothing
168     * when {@linkplain SymbolConstants#SECURE_ENABLED security is disabled} (which is often
169     * the case in development mode). This only affects how the Form's action attribute is rendered, there is
170     * not (currently) a check that the form is actually submitted securely.
171     */
172    @Parameter
173    private boolean secure;
174
175    /**
176     * Prefix value used when searching for validation messages and constraints.
177     * The default is the Form component's
178     * id. This is overridden by {@link org.apache.tapestry5.corelib.components.BeanEditForm}.
179     *
180     * @see org.apache.tapestry5.services.FormSupport#getFormValidationId()
181     */
182    @Parameter
183    private String validationId;
184
185    /**
186     * Object to validate during the form submission process. The default is the Form component's container.
187     * This parameter should only be used in combination with the Bean Validation Library.
188     */
189    @Parameter
190    private Object validate;
191
192    /**
193     * When true, the the form will submit as an asynchronous request (via XmlHttpRequest); the event handler methods
194     * can make use of the {@link org.apache.tapestry5.services.ajax.AjaxResponseRenderer} in order to force content
195     * updates to the client.  This is used as an alternative to placing the form inside a {@link org.apache.tapestry5.corelib.components.Zone}
196     * and binding the {@code zone} parameter.
197     *
198     * @since 5.4
199     */
200    @Parameter
201    private boolean async = false;
202
203    @Inject
204    private Logger logger;
205
206    @Inject
207    private Environment environment;
208
209    @Inject
210    private ComponentResources resources;
211
212    @Inject
213    private Messages messages;
214
215    @Environmental
216    private JavaScriptSupport javascriptSupport;
217
218    @Inject
219    private Request request;
220
221    @Inject
222    private ComponentSource source;
223
224    @Inject
225    @Symbol(InternalSymbols.PRE_SELECTED_FORM_NAMES)
226    private String preselectedFormNames;
227
228
229    /**
230     * Starting in 5.4, this is a simple, non-persistent property, with no extra magic tricks.
231     */
232    private ValidationTracker defaultTracker;
233
234    @Inject
235    @Symbol(SymbolConstants.SECURE_ENABLED)
236    private boolean secureEnabled;
237
238    private InternalFormSupport formSupport;
239
240    private Element form;
241
242    private Element div;
243
244    // Collects a stream of component actions. Each action goes in as a UTF
245    // string (the component
246    // component id), followed by a ComponentAction
247
248    private ComponentActionSink actionSink;
249
250    @SuppressWarnings("unchecked")
251    @Environmental
252    private TrackableComponentEventCallback eventCallback;
253
254    @Inject
255    private ClientDataEncoder clientDataEncoder;
256
257    @Inject
258    private PropertyAccess propertyAccess;
259
260    @Inject
261    private DeprecationWarning deprecationWarning;
262
263    private String clientId;
264
265    @Inject
266    private ComponentSource componentSource;
267
268    String defaultValidationId()
269    {
270        return resources.getId();
271    }
272
273    Object defaultValidate()
274    {
275        return resources.getContainer();
276    }
277
278    /**
279     * Returns an instance of {@link ValidationTrackerImpl}, lazily creating it as needed. This property
280     * is the default for the <strong>tracker</strong> parameter; the property (as of Tapestry 5.4) is not
281     * persistent.
282     *
283     * @return per-request cached instance
284     */
285    public ValidationTracker getDefaultTracker()
286    {
287        if (defaultTracker == null)
288        {
289            defaultTracker = new ValidationTrackerImpl();
290        }
291
292        return defaultTracker;
293    }
294
295    /**
296     * @deprecated In 5.4; previously used only for testing
297     */
298    public void setDefaultTracker(ValidationTracker defaultTracker)
299    {
300        this.defaultTracker = defaultTracker;
301    }
302
303    void setupRender()
304    {
305        FormSupport existing = environment.peek(FormSupport.class);
306
307        if (existing != null)
308        {
309            throw new TapestryException(messages.get("core-form-nesting-not-allowed"), existing, null);
310        }
311
312        if (clientValidation == ClientValidation.BLUR)
313        {
314            deprecationWarning.componentParameterValue(resources, "clientValidation", clientValidation, "BLUR is no longer supported, starting in 5.4. Validation will occur as with SUBMIT.");
315        }
316    }
317
318    void beginRender(MarkupWriter writer)
319    {
320        Link link = resources.createFormEventLink(EventConstants.ACTION, context);
321
322        String actionURL = secure && secureEnabled ? link.toAbsoluteURI(true) : link.toURI();
323
324        actionSink = new ComponentActionSink(logger, clientDataEncoder);
325
326        clientId = javascriptSupport.allocateClientId(resources);
327
328        // Pre-register some names, to prevent client-side collisions with function names
329        // attached to the JS Form object.
330
331        IdAllocator allocator = new IdAllocator();
332
333        preallocateNames(allocator);
334
335        formSupport = createRenderTimeFormSupport(clientId, actionSink, allocator);
336
337        environment.push(FormSupport.class, formSupport);
338        environment.push(ValidationTracker.class, tracker);
339
340        if (autofocus)
341        {
342            ValidationDecorator autofocusDecorator = new AutofocusValidationDecorator(
343                    environment.peek(ValidationDecorator.class), tracker, javascriptSupport);
344            environment.push(ValidationDecorator.class, autofocusDecorator);
345        }
346
347        // Now that the environment is setup, inform the component or other
348        // listeners that the form
349        // is about to render.
350
351        resources.triggerEvent(EventConstants.PREPARE_FOR_RENDER, context, null);
352
353        resources.triggerEvent(EventConstants.PREPARE, context, null);
354
355        // Push BeanValidationContext only after the container had a chance to prepare
356        environment.push(BeanValidationContext.class, new BeanValidationContextImpl(validate));
357
358        // Save the form element for later, in case we want to write an encoding
359        // type attribute.
360
361        form = writer.element("form",
362                "id", clientId,
363                "method", "post",
364                "action", actionURL,
365                "data-update-zone", zone);
366
367        if (clientValidation != ClientValidation.NONE)
368        {
369            writer.attributes("data-validate", "submit");
370        }
371
372        if (async)
373        {
374            javascriptSupport.require("t5/core/zone");
375            writer.attributes("data-async-trigger", true);
376        }
377
378        resources.renderInformalParameters(writer);
379
380        div = writer.element("div");
381
382        for (String parameterName : link.getParameterNames())
383        {
384            String[] values = link.getParameterValues(parameterName);
385
386            for (String value : values)
387            {
388                // The parameter value is expected to be encoded,
389                // but the input value shouldn't be encoded.
390                try
391                {
392                    value = URLDecoder.decode(value, "UTF-8");
393                }
394                catch (UnsupportedEncodingException e)
395                {
396                    logger.error(String.format(
397                            "Enable to decode parameter value for parameter %s in form %s",
398                            parameterName, form.getName()), e);
399                }
400                writer.element("input", "type", "hidden", "name", parameterName, "value", value);
401                writer.end();
402            }
403        }
404
405        writer.end(); // div
406
407        environment.peek(Heartbeat.class).begin();
408    }
409
410    /**
411     * Creates an {@link org.apache.tapestry5.corelib.internal.InternalFormSupport} for
412     * this Form. This method is used
413     * by {@link org.apache.tapestry5.corelib.components.FormInjector}.
414     * <p/>
415     * This method may also be invoked as the handler for the "internalCreateRenderTimeFormSupport" event.
416     *
417     * @param clientId
418     *         the client-side id for the rendered form
419     *         element
420     * @param actionSink
421     *         used to collect component actions that will, ultimately, be
422     *         written as the t:formdata hidden
423     *         field
424     * @param allocator
425     *         used to allocate unique ids
426     * @return form support object
427     */
428    @OnEvent("internalCreateRenderTimeFormSupport")
429    InternalFormSupport createRenderTimeFormSupport(String clientId, ComponentActionSink actionSink,
430                                                    IdAllocator allocator)
431    {
432        return new FormSupportImpl(resources, clientId, actionSink,
433                clientValidation != ClientValidation.NONE, allocator, validationId);
434    }
435
436    void afterRender(MarkupWriter writer)
437    {
438        environment.peek(Heartbeat.class).end();
439
440        formSupport.executeDeferred();
441
442        String encodingType = formSupport.getEncodingType();
443
444        if (encodingType != null)
445        {
446            form.forceAttributes("enctype", encodingType);
447        }
448
449        writer.end(); // form
450
451        div.element("input", "type", "hidden", "name", FORM_DATA, "value", actionSink.getClientData());
452        div.pop();
453
454        if (autofocus)
455        {
456            environment.pop(ValidationDecorator.class);
457        }
458    }
459
460    void cleanupRender()
461    {
462        environment.pop(FormSupport.class);
463
464        formSupport = null;
465
466        environment.pop(ValidationTracker.class);
467
468        tracker.clear();
469
470        environment.pop(BeanValidationContext.class);
471    }
472
473    @SuppressWarnings(
474            {"unchecked", "InfiniteLoopStatement"})
475    Object onAction(EventContext context) throws IOException
476    {
477        tracker.clear();
478
479        formSupport = new FormSupportImpl(resources, validationId);
480
481        environment.push(ValidationTracker.class, tracker);
482        environment.push(FormSupport.class, formSupport);
483
484        Heartbeat heartbeat = new HeartbeatImpl();
485
486        environment.push(Heartbeat.class, heartbeat);
487
488        heartbeat.begin();
489
490        boolean didPushBeanValidationContext = false;
491
492        try
493        {
494            resources.triggerContextEvent(EventConstants.PREPARE_FOR_SUBMIT, context, eventCallback);
495
496            if (eventCallback.isAborted())
497                return true;
498
499            resources.triggerContextEvent(EventConstants.PREPARE, context, eventCallback);
500            if (eventCallback.isAborted())
501                return true;
502
503            if (isFormCancelled())
504            {
505                executeStoredActions(true);
506
507                resources.triggerContextEvent(EventConstants.CANCELED, context, eventCallback);
508                if (eventCallback.isAborted())
509                    return true;
510            }
511
512            environment.push(BeanValidationContext.class, new BeanValidationContextImpl(validate));
513
514            didPushBeanValidationContext = true;
515
516            executeStoredActions(false);
517
518            heartbeat.end();
519
520            formSupport.executeDeferred();
521
522            fireValidateEvent(EventConstants.VALIDATE, context, eventCallback);
523
524            if (eventCallback.isAborted())
525                return true;
526
527            // Let the listeners know about overall success or failure. Most
528            // listeners fall into
529            // one of those two camps.
530
531            // If the tracker has no errors, then clear it of any input values
532            // as well, so that the next page render will be "clean" and show
533            // true persistent data, not value from the previous form
534            // submission.
535
536            if (!tracker.getHasErrors())
537            {
538                tracker.clear();
539            }
540
541            String eventType = tracker.getHasErrors()
542                    ? EventConstants.FAILURE
543                    : EventConstants.SUCCESS;
544
545            resources.triggerContextEvent(eventType, context, eventCallback);
546
547            if (eventCallback.isAborted())
548            {
549                return true;
550            }
551
552            // Lastly, tell anyone whose interested that the form is completely
553            // submitted.
554
555            resources.triggerContextEvent(EventConstants.SUBMIT, context, eventCallback);
556
557            if (eventCallback.isAborted())
558            {
559                return true;
560            }
561
562            // For traditional request with no validation exceptions, re-render the
563            // current page immediately, as-is.  Prior to Tapestry 5.4, a redirect was
564            // sent that required that the tracker be persisted across requests.
565            // See https://issues.apache.org/jira/browse/TAP5-1808
566
567            if (tracker.getHasErrors() && !request.isXHR())
568            {
569                return STREAM_ACTIVE_PAGE_CONTENT;
570            }
571
572            // The event will not work its way up.
573
574            return false;
575
576        } finally
577        {
578            environment.pop(Heartbeat.class);
579            environment.pop(FormSupport.class);
580
581            environment.pop(ValidationTracker.class);
582
583            if (didPushBeanValidationContext)
584            {
585                environment.pop(BeanValidationContext.class);
586            }
587        }
588    }
589
590    private boolean isFormCancelled()
591    {
592        // The "cancel" query parameter is reserved for this purpose; if it is present then the form was canceled on the
593        // client side.  For image submits, there will be two parameters: "cancel.x" and "cancel.y".
594
595        if (request.getParameter(InternalConstants.CANCEL_NAME) != null ||
596                request.getParameter(InternalConstants.CANCEL_NAME + ".x") != null)
597        {
598            return true;
599        }
600
601        // When JavaScript is involved, it's more complicated. In fact, this is part of HLS's desire
602        // to have all forms submit via XHR when JavaScript is present, since it would provide
603        // an opportunity to get the submitting element's value into the request properly.
604
605        String raw = request.getParameter(SUBMITTING_ELEMENT_ID);
606
607        if (InternalUtils.isNonBlank(raw) &&
608                new JSONArray(raw).getString(1).equals(InternalConstants.CANCEL_NAME))
609        {
610            return true;
611        }
612
613        return false;
614    }
615
616
617    private void fireValidateEvent(String eventName, EventContext context, TrackableComponentEventCallback callback)
618    {
619        try
620        {
621            resources.triggerContextEvent(eventName, context, callback);
622        } catch (RuntimeException ex)
623        {
624            ValidationException ve = ExceptionUtils.findCause(ex, ValidationException.class, propertyAccess);
625
626            if (ve != null)
627            {
628                ValidationTracker tracker = environment.peek(ValidationTracker.class);
629
630                tracker.recordError(ve.getMessage());
631
632                return;
633            }
634
635            throw ex;
636        }
637    }
638
639    /**
640     * Pulls the stored actions out of the request, converts them from MIME
641     * stream back to object stream and then
642     * objects, and executes them.
643     */
644    private void executeStoredActions(boolean forFormCancel)
645    {
646        String[] values = request.getParameters(FORM_DATA);
647
648        if (!request.getMethod().equals("POST") || values == null)
649            throw new RuntimeException(messages.format("core-invalid-form-request", FORM_DATA));
650
651        // Due to Ajax (FormInjector) there may be multiple values here, so
652        // handle each one individually.
653
654        for (String clientEncodedActions : values)
655        {
656            if (InternalUtils.isBlank(clientEncodedActions))
657                continue;
658
659            logger.debug("Processing actions: {}", clientEncodedActions);
660
661            ObjectInputStream ois = null;
662
663            Component component = null;
664
665            try
666            {
667                ois = clientDataEncoder.decodeClientData(clientEncodedActions);
668
669                while (!eventCallback.isAborted())
670                {
671                    String componentId = ois.readUTF();
672                    boolean cancelAction = ois.readBoolean();
673                    ComponentAction action = (ComponentAction) ois.readObject();
674
675                    // Actions are a mix of ordinary actions and cancel actions.  Filter out one set or the other
676                    // based on whether the form was submitted or cancelled.
677                    if (forFormCancel != cancelAction) { continue; }
678
679                    component = source.getComponent(componentId);
680
681                    logger.debug("Processing: {} {}", componentId, action);
682
683                    action.execute(component);
684
685                    component = null;
686                }
687            } catch (EOFException ex)
688            {
689                // Expected
690            } catch (Exception ex)
691            {
692                Location location = component == null ? null : component.getComponentResources().getLocation();
693
694                throw new TapestryException(ex.getMessage(), location, ex);
695            } finally
696            {
697                InternalUtils.close(ois);
698            }
699        }
700    }
701
702    public void recordError(String errorMessage)
703    {
704        tracker.recordError(errorMessage);
705    }
706
707    public void recordError(Field field, String errorMessage)
708    {
709        tracker.recordError(field, errorMessage);
710    }
711
712    public boolean getHasErrors()
713    {
714        return tracker.getHasErrors();
715    }
716
717    public boolean isValid()
718    {
719        return !tracker.getHasErrors();
720    }
721
722    public void clearErrors()
723    {
724        tracker.clear();
725    }
726
727    // For testing:
728
729    void setTracker(ValidationTracker tracker)
730    {
731        this.tracker = tracker;
732    }
733
734    /**
735     * Forms use the same value for their name and their id attribute.
736     */
737    public String getClientId()
738    {
739        return clientId;
740    }
741
742    private void preallocateNames(IdAllocator idAllocator)
743    {
744        for (String name : TapestryInternalUtils.splitAtCommas(preselectedFormNames))
745        {
746            idAllocator.allocateId(name);
747            // See https://issues.apache.org/jira/browse/TAP5-1632
748            javascriptSupport.allocateClientId(name);
749
750        }
751
752        Component activePage = componentSource.getActivePage();
753
754        // This is unlikely but may be possible if people override some of the standard
755        // exception reporting logic.
756
757        if (activePage == null)
758            return;
759
760        ComponentResources activePageResources = activePage.getComponentResources();
761
762        try
763        {
764
765            activePageResources.triggerEvent(EventConstants.PREALLOCATE_FORM_CONTROL_NAMES, new Object[]
766                    {idAllocator}, null);
767        } catch (RuntimeException ex)
768        {
769            logger.error(
770                    String.format("Unable to obtrain form control names to preallocate: %s",
771                            ExceptionUtils.toMessage(ex)), ex);
772        }
773    }
774}