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.beaneditor.BeanModel;
018import org.apache.tapestry5.beaneditor.PropertyModel;
019import org.apache.tapestry5.corelib.data.GridPagerPosition;
020import org.apache.tapestry5.grid.*;
021import org.apache.tapestry5.internal.TapestryInternalUtils;
022import org.apache.tapestry5.internal.beaneditor.BeanModelUtils;
023import org.apache.tapestry5.internal.bindings.AbstractBinding;
024import org.apache.tapestry5.ioc.annotations.Inject;
025import org.apache.tapestry5.ioc.internal.util.InternalUtils;
026import org.apache.tapestry5.services.BeanModelSource;
027import org.apache.tapestry5.services.ComponentDefaultProvider;
028import org.apache.tapestry5.services.ComponentEventResultProcessor;
029import org.apache.tapestry5.services.FormSupport;
030import org.apache.tapestry5.services.javascript.JavaScriptSupport;
031
032import java.io.IOException;
033import java.util.Collections;
034import java.util.List;
035
036/**
037 * A grid presents tabular data. It is a composite component, created in terms of several sub-components. The
038 * sub-components are statically wired to the Grid, as it provides access to the data and other models that they need.
039 *
040 * A Grid may operate inside a {@link org.apache.tapestry5.corelib.components.Form}. By overriding the cell renderers of
041 * properties, the default output-only behavior can be changed to produce a complex form with individual control for
042 * editing properties of each row. There is a big caveat here: if the order of rows provided by
043 * the {@link org.apache.tapestry5.grid.GridDataSource} changes between render and form submission, then there's the
044 * possibility that data will be applied to the wrong server-side objects.
045 *
046 * For this reason, when using Grid and Form together, you should generally
047 * provide the Grid with a {@link org.apache.tapestry5.ValueEncoder} (via the
048 * encoder parameter), or use an entity type for the "row" parameter for which
049 * Tapestry can provide a ValueEncoder automatically. This will allow Tapestry
050 * to use a unique ID for each row that doesn't change when rows are reordered.
051 *
052 * @tapestrydoc
053 * @see org.apache.tapestry5.beaneditor.BeanModel
054 * @see org.apache.tapestry5.services.BeanModelSource
055 * @see org.apache.tapestry5.grid.GridDataSource
056 * @see BeanEditForm
057 * @see BeanDisplay
058 * @see Loop
059 */
060@SupportsInformalParameters
061public class Grid implements GridModel, ClientElement
062{
063    /**
064     * The source of data for the Grid to display. This will usually be a List or array but can also be an explicit
065     * {@link GridDataSource}. For Lists and object arrays, a GridDataSource is created automatically as a wrapper
066     * around the underlying List.
067     */
068    @Parameter(required = true, autoconnect = true)
069    private GridDataSource source;
070
071    /**
072     * A wrapper around the provided GridDataSource that caches access to the availableRows property. This is the source
073     * provided to sub-components.
074     */
075    private GridDataSource cachingSource;
076
077    /**
078     * The number of rows of data displayed on each page. If there are more rows than will fit, the Grid will divide up
079     * the rows into "pages" and (normally) provide a pager to allow the user to navigate within the overall result
080     * set.
081     */
082    @Parameter(BindingConstants.SYMBOL + ":" + ComponentParameterConstants.GRID_ROWS_PER_PAGE)
083    private int rowsPerPage;
084
085    /**
086     * Defines where the pager (used to navigate within the "pages" of results) should be displayed: "top", "bottom",
087     * "both" or "none".
088     */
089    @Parameter(value = BindingConstants.SYMBOL + ":" + ComponentParameterConstants.GRID_PAGER_POSITION,
090            defaultPrefix = BindingConstants.LITERAL)
091    private GridPagerPosition pagerPosition;
092
093    /**
094     * Used to store the current object being rendered (for the current row). This is used when parameter blocks are
095     * provided to override the default cell renderer for a particular column ... the components within the block can
096     * use the property bound to the row parameter to know what they should render.
097     */
098    @Parameter(principal = true)
099    private Object row;
100
101    /**
102     * Optional output parameter used to identify the index of the column being rendered.
103     */
104    @Parameter
105    private int columnIndex;
106
107    /**
108     * The model used to identify the properties to be presented and the order of presentation. The model may be
109     * omitted, in which case a default model is generated from the first object in the data source (this implies that
110     * the objects provided by the source are uniform). The model may be explicitly specified to override the default
111     * behavior, say to reorder or rename columns or add additional columns. The add, include,
112     * exclude and reorder
113     * parameters are <em>only</em> applied to a default model, not an explicitly provided one.
114     */
115    @Parameter
116    private BeanModel model;
117
118    /**
119     * The model parameter after modification due to the add, include, exclude and reorder parameters.
120     */
121    private BeanModel dataModel;
122
123    /**
124     * The model used to handle sorting of the Grid. This is generally not specified, and the built-in model supports
125     * only single column sorting. The sort constraints (the column that is sorted, and ascending vs. descending) is
126     * stored as persistent fields of the Grid component.
127     */
128    @Parameter
129    private GridSortModel sortModel;
130
131    /**
132     * A comma-separated list of property names to be added to the {@link org.apache.tapestry5.beaneditor.BeanModel}.
133     * Cells for added columns will be blank unless a cell override is provided. This parameter is only used
134     * when a default model is created automatically.
135     */
136    @Parameter(defaultPrefix = BindingConstants.LITERAL)
137    private String add;
138
139    /**
140     * A comma-separated list of property names to be retained from the
141     * {@link org.apache.tapestry5.beaneditor.BeanModel}.
142     * Only these properties will be retained, and the properties will also be reordered. The names are
143     * case-insensitive. This parameter is only used
144     * when a default model is created automatically.
145     */
146    @SuppressWarnings("unused")
147    @Parameter(defaultPrefix = BindingConstants.LITERAL)
148    private String include;
149
150    /**
151     * A comma-separated list of property names to be removed from the {@link org.apache.tapestry5.beaneditor.BeanModel}
152     * .
153     * The names are case-insensitive. This parameter is only used
154     * when a default model is created automatically.
155     */
156    @Parameter(defaultPrefix = BindingConstants.LITERAL)
157    private String exclude;
158
159    /**
160     * A comma-separated list of property names indicating the order in which the properties should be presented. The
161     * names are case insensitive. Any properties not indicated in the list will be appended to the end of the display
162     * order. This parameter is only used
163     * when a default model is created automatically.
164     */
165    @Parameter(defaultPrefix = BindingConstants.LITERAL)
166    private String reorder;
167
168    /**
169     * A Block to render instead of the table (and pager, etc.) when the source is empty. The default is simply the text
170     * "There is no data to display". This parameter is used to customize that message, possibly including components to
171     * allow the user to create new objects.
172     */
173    //@Parameter(value = BindingConstants.SYMBOL + ":" + ComponentParameterConstants.GRID_EMPTY_BLOCK,
174    @Parameter(value = "block:empty",
175            defaultPrefix = BindingConstants.LITERAL)
176    private Block empty;
177
178    /**
179     * CSS class for the &lt;table&gt; element. In addition, informal parameters to the Grid are rendered in the table
180     * element.
181     */
182    @Parameter(name = "class", defaultPrefix = BindingConstants.LITERAL,
183            value = BindingConstants.SYMBOL + ":" + ComponentParameterConstants.GRID_TABLE_CSS_CLASS)
184    @Property(write = false)
185    private String tableClass;
186
187    /**
188     * If true, then the Grid will be wrapped in an element that acts like a
189     * {@link org.apache.tapestry5.corelib.components.Zone}; all the paging and sorting links will refresh the zone,
190     * repainting the entire grid within it, but leaving the rest of the page (outside the zone) unchanged.
191     */
192    @Parameter
193    private boolean inPlace;
194
195    /**
196     * If true, then the Grid will also render a table element complete with headers if the data source is empty.
197     * If set to true, a model parameter will have to be specified. A default model for a specific class can be
198     * created using {@link BeanModelSource#createDisplayModel(Class, org.apache.tapestry5.ioc.Messages)}.
199     */
200    @Parameter
201    private boolean renderTableIfEmpty = false;
202
203
204    /**
205     * The name of the pseudo-zone that encloses the Grid. Starting in 5.4, this is always either
206     * null or "^" and is not really used the way it was in 5.3; instead it triggers the addition
207     * of a {@code data-inplace-grid-links} attribute in a div surrounding any links related to
208     * sorting or pagination. The rest is sorted out on the client. See module {@code t5/core/zone}.
209     */
210    @Property(write = false)
211    private String zone;
212
213    private boolean didRenderZoneDiv;
214
215
216    /**
217     * The pagination model for the Grid, which encapsulates current page, sort column id,
218     * and sort ascending/descending. If not bound, a persistent property of the Grid is used.
219     * When rendering the Grid in a loop, this should be bound in some way to keep successive instances
220     * of the Grid configured individually.
221     *
222     * @since 5.4
223     */
224    @Parameter(value = "defaultPaginationModel")
225    private GridPaginationModel paginationModel;
226
227    @Persist
228    private GridPaginationModel defaultPaginationModel;
229
230    @Inject
231    private ComponentResources resources;
232
233    @Inject
234    private BeanModelSource modelSource;
235
236    @Environmental
237    private JavaScriptSupport javaScriptSupport;
238
239    @Component(parameters =
240            {"index=inherit:columnIndex", "lean=inherit:lean", "overrides=overrides", "zone=zone"})
241    private GridColumns columns;
242
243    @Component(parameters =
244            {"columnIndex=inherit:columnIndex", "rowsPerPage=rowsPerPage", "currentPage=currentPage", "row=row",
245                    "overrides=overrides"}, publishParameters = "rowIndex,rowClass,volatile,encoder,lean")
246    private GridRows rows;
247
248    @Component(parameters =
249            {"source=dataSource", "rowsPerPage=rowsPerPage", "currentPage=currentPage", "zone=zone"})
250    private GridPager pager;
251
252    @Component(parameters = "to=pagerTop")
253    private Delegate pagerTop;
254
255    @Component(parameters = "to=pagerBottom")
256    private Delegate pagerBottom;
257
258    @Component(parameters = "class=tableClass", inheritInformalParameters = true)
259    private Any table;
260
261    @Environmental(false)
262    private FormSupport formSupport;
263
264    /**
265     * Defines where block and label overrides are obtained from. By default, the Grid component provides block
266     * overrides (from its block parameters).
267     */
268    @Parameter(value = "this", allowNull = false)
269    @Property(write = false)
270    private PropertyOverrides overrides;
271
272    /**
273     * Set up via the traditional or Ajax component event request handler
274     */
275    @Environmental
276    private ComponentEventResultProcessor componentEventResultProcessor;
277
278    @Inject
279    private ComponentDefaultProvider defaultsProvider;
280
281    ValueEncoder defaultEncoder()
282    {
283        return defaultsProvider.defaultValueEncoder("row", resources);
284    }
285
286    /**
287     * A version of GridDataSource that caches the availableRows property. This addresses TAPESTRY-2245.
288     */
289    static class CachingDataSource implements GridDataSource
290    {
291        private final GridDataSource delegate;
292
293        private boolean availableRowsCached;
294
295        private int availableRows;
296
297        CachingDataSource(GridDataSource delegate)
298        {
299            this.delegate = delegate;
300        }
301
302        public int getAvailableRows()
303        {
304            if (!availableRowsCached)
305            {
306                availableRows = delegate.getAvailableRows();
307                availableRowsCached = true;
308            }
309
310            return availableRows;
311        }
312
313        public void prepare(int startIndex, int endIndex, List<SortConstraint> sortConstraints)
314        {
315            delegate.prepare(startIndex, endIndex, sortConstraints);
316        }
317
318        public Object getRowValue(int index)
319        {
320            return delegate.getRowValue(index);
321        }
322
323        public Class getRowType()
324        {
325            return delegate.getRowType();
326        }
327    }
328
329    /**
330     * Default implementation that only allows a single column to be the sort column, and stores the sort information as
331     * persistent fields of the Grid component.
332     */
333    class DefaultGridSortModel implements GridSortModel
334    {
335        public ColumnSort getColumnSort(String columnId)
336        {
337            if (paginationModel == null || !TapestryInternalUtils.isEqual(columnId, paginationModel.getSortColumnId()))
338            {
339                return ColumnSort.UNSORTED;
340            }
341
342            return getColumnSort();
343        }
344
345        private ColumnSort getColumnSort()
346        {
347            return getSortAscending() ? ColumnSort.ASCENDING : ColumnSort.DESCENDING;
348        }
349
350        public void updateSort(String columnId)
351        {
352            assert InternalUtils.isNonBlank(columnId);
353
354            if (columnId.equals(paginationModel.getSortColumnId()))
355            {
356                setSortAscending(!getSortAscending());
357                return;
358            }
359
360            paginationModel.setSortColumnId(columnId);
361            setSortAscending(true);
362        }
363
364        public List<SortConstraint> getSortConstraints()
365        {
366            // In a few limited cases we may not have yet hit the SetupRender phase, and the model may be null.
367            if (paginationModel == null || paginationModel.getSortColumnId() == null)
368            {
369                return Collections.emptyList();
370            }
371
372            PropertyModel sortModel = getDataModel().getById(paginationModel.getSortColumnId());
373
374            SortConstraint constraint = new SortConstraint(sortModel, getColumnSort());
375
376            return Collections.singletonList(constraint);
377        }
378
379        public void clear()
380        {
381            paginationModel.setSortColumnId(null);
382            paginationModel.setSortAscending(null);
383        }
384    }
385
386    GridSortModel defaultSortModel()
387    {
388        return new DefaultGridSortModel();
389    }
390
391    /**
392     * Returns a {@link org.apache.tapestry5.Binding} instance that attempts to identify the model from the source
393     * parameter (via {@link org.apache.tapestry5.grid.GridDataSource#getRowType()}. Subclasses may override to provide
394     * a different mechanism. The returning binding is variant (not invariant).
395     *
396     * @see BeanModelSource#createDisplayModel(Class, org.apache.tapestry5.ioc.Messages)
397     */
398    protected Binding defaultModel()
399    {
400
401        return new AbstractBinding()
402        {
403            public Object get()
404            {
405                // Get the default row type from the data source
406
407                GridDataSource gridDataSource = source;
408
409                Class rowType = gridDataSource.getRowType();
410
411                if (renderTableIfEmpty || rowType == null)
412                    throw new RuntimeException(
413                            String.format(
414                                    "Unable to determine the bean type for rows from %s. You should bind the model parameter explicitly.",
415                                    gridDataSource));
416
417                // Properties do not have to be read/write
418
419                return modelSource.createDisplayModel(rowType, overrides.getOverrideMessages());
420            }
421
422            /**
423             * Returns false. This may be overkill, but it basically exists because the model is
424             * inherently mutable and therefore may contain client-specific state and needs to be
425             * discarded at the end of the request. If the model were immutable, then we could leave
426             * invariant as true.
427             */
428            @Override
429            public boolean isInvariant()
430            {
431                return false;
432            }
433        };
434    }
435
436    static final ComponentAction<Grid> SETUP_DATA_SOURCE = new ComponentAction<Grid>()
437    {
438        private static final long serialVersionUID = 8545187927995722789L;
439
440        public void execute(Grid component)
441        {
442            component.setupDataSource();
443        }
444
445        @Override
446        public String toString()
447        {
448            return "Grid.SetupDataSource";
449        }
450    };
451
452    Object setupRender()
453    {
454        if (formSupport != null)
455        {
456            formSupport.store(this, SETUP_DATA_SOURCE);
457        }
458
459        setupDataSource();
460
461        // If there's no rows, display the empty block placeholder.
462
463        return !renderTableIfEmpty && cachingSource.getAvailableRows() == 0 ? empty : null;
464    }
465
466    void cleanupRender()
467    {
468        // if an inPlace Grid is rendered inside a Loop, be sure to generate a new wrapper
469        // zone for each iteration (TAP5-2256)
470        zone = null;
471
472        // If grid is rendered inside a Loop. be sure to generate a new data model for
473        // each iteration (TAP5-2470)
474        dataModel = null;
475    }
476
477    public GridPaginationModel getDefaultPaginationModel()
478    {
479        if (defaultPaginationModel == null)
480        {
481            defaultPaginationModel = new GridPaginationModelImpl();
482        }
483
484        return defaultPaginationModel;
485    }
486
487    void setupDataSource()
488    {
489        // TAP5-34: We pass the source into the CachingDataSource now; previously
490        // we were accessing source directly, but during submit the value wasn't
491        // cached, and therefore access was very inefficient, and sorting was
492        // very inconsistent during the processing of the form submission.
493
494        cachingSource = new CachingDataSource(source);
495
496        int availableRows = cachingSource.getAvailableRows();
497
498        if (availableRows == 0)
499            return;
500
501        int maxPage = ((availableRows - 1) / rowsPerPage) + 1;
502
503        // This captures when the number of rows has decreased, typically due to deletions.
504
505        int effectiveCurrentPage = getCurrentPage();
506
507        if (effectiveCurrentPage > maxPage)
508            effectiveCurrentPage = maxPage;
509
510        int startIndex = (effectiveCurrentPage - 1) * rowsPerPage;
511
512        int endIndex = Math.min(startIndex + rowsPerPage - 1, availableRows - 1);
513
514        cachingSource.prepare(startIndex, endIndex, sortModel.getSortConstraints());
515    }
516
517    Object beginRender(MarkupWriter writer)
518    {
519        // Skip rendering of component (template, body, etc.) when there's nothing to display.
520        // The empty placeholder will already have rendered.
521
522        if (cachingSource.getAvailableRows() == 0)
523            return !renderTableIfEmpty ? false : null;
524
525        if (inPlace && zone == null)
526        {
527            javaScriptSupport.require("t5/core/zone");
528
529            writer.element("div", "data-container-type", "zone");
530
531            didRenderZoneDiv = true;
532
533            // Through Tapestry 5.3, we had a specific id for the zone that had to be passed down to the
534            // GridPager and etc.  That's no longer necessary, so zone will always be null or "^".  We don't
535            // even need any special ids to be allocated!
536            zone = "^";
537        }
538
539        return null;
540    }
541
542    void afterRender(MarkupWriter writer)
543    {
544        if (didRenderZoneDiv)
545        {
546            writer.end(); // div
547            didRenderZoneDiv = false;
548        }
549    }
550
551    public BeanModel getDataModel()
552    {
553        if (dataModel == null)
554        {
555            dataModel = model;
556
557            BeanModelUtils.modify(dataModel, add, include, exclude, reorder);
558        }
559
560        return dataModel;
561    }
562
563    public int getNumberOfProperties()
564    {
565        return getDataModel().getPropertyNames().size();
566    }
567
568    public GridDataSource getDataSource()
569    {
570        return cachingSource;
571    }
572
573    public GridSortModel getSortModel()
574    {
575        return sortModel;
576    }
577
578    public Object getPagerTop()
579    {
580        return pagerPosition.isMatchTop() ? pager : null;
581    }
582
583    public Object getPagerBottom()
584    {
585        return pagerPosition.isMatchBottom() ? pager : null;
586    }
587
588    public int getCurrentPage()
589    {
590        Integer currentPage = paginationModel.getCurrentPage();
591
592        return currentPage == null ? 1 : currentPage;
593    }
594
595    public void setCurrentPage(int currentPage)
596    {
597        paginationModel.setCurrentPage(currentPage);
598    }
599
600    private boolean getSortAscending()
601    {
602        Boolean sortAscending = paginationModel.getSortAscending();
603
604        return sortAscending != null && sortAscending.booleanValue();
605    }
606
607    private void setSortAscending(boolean sortAscending)
608    {
609        paginationModel.setSortAscending(sortAscending);
610    }
611
612    public int getRowsPerPage()
613    {
614        return rowsPerPage;
615    }
616
617    public Object getRow()
618    {
619        return row;
620    }
621
622    public void setRow(Object row)
623    {
624        this.row = row;
625    }
626
627    /**
628     * Resets the Grid to inital settings; this sets the current page to one, and
629     * {@linkplain org.apache.tapestry5.grid.GridSortModel#clear() clears the sort model}.
630     */
631    public void reset()
632    {
633        sortModel.clear();
634        setCurrentPage(1);
635    }
636
637    /**
638     * Event handler for inplaceupdate event triggered from nested components when an Ajax update occurs. The event
639     * context will carry the zone, which is recorded here, to allow the Grid and its sub-components to properly
640     * re-render themselves. Invokes
641     * {@link org.apache.tapestry5.services.ComponentEventResultProcessor#processResultValue(Object)} passing this (the
642     * Grid component) as the content provider for the update.
643     */
644    void onInPlaceUpdate() throws IOException
645    {
646        this.zone = "^";
647
648        componentEventResultProcessor.processResultValue(this);
649    }
650
651    public String getClientId()
652    {
653        return table.getClientId();
654    }
655}