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 * <p/>
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 * <p/>
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    @Property
228    @Persist
229    private GridPaginationModel defaultPaginationModel;
230
231    @Inject
232    private ComponentResources resources;
233
234    @Inject
235    private BeanModelSource modelSource;
236
237    @Environmental
238    private JavaScriptSupport javaScriptSupport;
239
240    @Component(parameters =
241            {"index=inherit:columnIndex", "lean=inherit:lean", "overrides=overrides", "zone=zone"})
242    private GridColumns columns;
243
244    @Component(parameters =
245            {"columnIndex=inherit:columnIndex", "rowsPerPage=rowsPerPage", "currentPage=currentPage", "row=row",
246                    "overrides=overrides"}, publishParameters = "rowIndex,rowClass,volatile,encoder,lean")
247    private GridRows rows;
248
249    @Component(parameters =
250            {"source=dataSource", "rowsPerPage=rowsPerPage", "currentPage=currentPage", "zone=zone"})
251    private GridPager pager;
252
253    @Component(parameters = "to=pagerTop")
254    private Delegate pagerTop;
255
256    @Component(parameters = "to=pagerBottom")
257    private Delegate pagerBottom;
258
259    @Component(parameters = "class=tableClass", inheritInformalParameters = true)
260    private Any table;
261
262    @Environmental(false)
263    private FormSupport formSupport;
264
265    /**
266     * Defines where block and label overrides are obtained from. By default, the Grid component provides block
267     * overrides (from its block parameters).
268     */
269    @Parameter(value = "this", allowNull = false)
270    @Property(write = false)
271    private PropertyOverrides overrides;
272
273    /**
274     * Set up via the traditional or Ajax component event request handler
275     */
276    @Environmental
277    private ComponentEventResultProcessor componentEventResultProcessor;
278
279    @Inject
280    private ComponentDefaultProvider defaultsProvider;
281
282    ValueEncoder defaultEncoder()
283    {
284        return defaultsProvider.defaultValueEncoder("row", resources);
285    }
286
287    /**
288     * A version of GridDataSource that caches the availableRows property. This addresses TAPESTRY-2245.
289     */
290    static class CachingDataSource implements GridDataSource
291    {
292        private final GridDataSource delegate;
293
294        private boolean availableRowsCached;
295
296        private int availableRows;
297
298        CachingDataSource(GridDataSource delegate)
299        {
300            this.delegate = delegate;
301        }
302
303        public int getAvailableRows()
304        {
305            if (!availableRowsCached)
306            {
307                availableRows = delegate.getAvailableRows();
308                availableRowsCached = true;
309            }
310
311            return availableRows;
312        }
313
314        public void prepare(int startIndex, int endIndex, List<SortConstraint> sortConstraints)
315        {
316            delegate.prepare(startIndex, endIndex, sortConstraints);
317        }
318
319        public Object getRowValue(int index)
320        {
321            return delegate.getRowValue(index);
322        }
323
324        public Class getRowType()
325        {
326            return delegate.getRowType();
327        }
328    }
329
330    /**
331     * Default implementation that only allows a single column to be the sort column, and stores the sort information as
332     * persistent fields of the Grid component.
333     */
334    class DefaultGridSortModel implements GridSortModel
335    {
336        public ColumnSort getColumnSort(String columnId)
337        {
338            if (paginationModel == null || !TapestryInternalUtils.isEqual(columnId, paginationModel.getSortColumnId()))
339            {
340                return ColumnSort.UNSORTED;
341            }
342
343            return getColumnSort();
344        }
345
346        private ColumnSort getColumnSort()
347        {
348            return getSortAscending() ? ColumnSort.ASCENDING : ColumnSort.DESCENDING;
349        }
350
351        public void updateSort(String columnId)
352        {
353            assert InternalUtils.isNonBlank(columnId);
354
355            setupPaginationModel();
356
357            if (columnId.equals(paginationModel.getSortColumnId()))
358            {
359                setSortAscending(!getSortAscending());
360                return;
361            }
362
363            paginationModel.setSortColumnId(columnId);
364            setSortAscending(true);
365        }
366
367        public List<SortConstraint> getSortConstraints()
368        {
369            // In a few limited cases we may not have yet hit the SetupRender phase, and the model may be null.
370            if (paginationModel == null || paginationModel.getSortColumnId() == null)
371            {
372                return Collections.emptyList();
373            }
374
375            PropertyModel sortModel = getDataModel().getById(paginationModel.getSortColumnId());
376
377            SortConstraint constraint = new SortConstraint(sortModel, getColumnSort());
378
379            return Collections.singletonList(constraint);
380        }
381
382        public void clear()
383        {
384            setupPaginationModel();
385            paginationModel.setSortColumnId(null);
386            paginationModel.setSortAscending(null);
387        }
388    }
389
390    GridSortModel defaultSortModel()
391    {
392        return new DefaultGridSortModel();
393    }
394
395    /**
396     * Returns a {@link org.apache.tapestry5.Binding} instance that attempts to identify the model from the source
397     * parameter (via {@link org.apache.tapestry5.grid.GridDataSource#getRowType()}. Subclasses may override to provide
398     * a different mechanism. The returning binding is variant (not invariant).
399     *
400     * @see BeanModelSource#createDisplayModel(Class, org.apache.tapestry5.ioc.Messages)
401     */
402    protected Binding defaultModel()
403    {
404
405        return new AbstractBinding()
406        {
407            public Object get()
408            {
409                // Get the default row type from the data source
410
411                GridDataSource gridDataSource = source;
412
413                Class rowType = gridDataSource.getRowType();
414
415                if (renderTableIfEmpty || rowType == null)
416                    throw new RuntimeException(
417                            String.format(
418                                    "Unable to determine the bean type for rows from %s. You should bind the model parameter explicitly.",
419                                    gridDataSource));
420
421                // Properties do not have to be read/write
422
423                return modelSource.createDisplayModel(rowType, overrides.getOverrideMessages());
424            }
425
426            /**
427             * Returns false. This may be overkill, but it basically exists because the model is
428             * inherently mutable and therefore may contain client-specific state and needs to be
429             * discarded at the end of the request. If the model were immutable, then we could leave
430             * invariant as true.
431             */
432            @Override
433            public boolean isInvariant()
434            {
435                return false;
436            }
437        };
438    }
439
440    static final ComponentAction<Grid> SETUP_DATA_SOURCE = new ComponentAction<Grid>()
441    {
442        private static final long serialVersionUID = 8545187927995722789L;
443
444        public void execute(Grid component)
445        {
446            component.setupDataSource();
447        }
448
449        @Override
450        public String toString()
451        {
452            return "Grid.SetupDataSource";
453        }
454    };
455
456    Object setupRender()
457    {
458        zone = null;
459
460        setupPaginationModel();
461
462        if (formSupport != null)
463        {
464            formSupport.store(this, SETUP_DATA_SOURCE);
465        }
466
467        setupDataSource();
468
469        // If there's no rows, display the empty block placeholder.
470
471        return !renderTableIfEmpty && cachingSource.getAvailableRows() == 0 ? empty : null;
472    }
473
474    private void setupPaginationModel()
475    {
476        if (paginationModel == null)
477        {
478            paginationModel = new GridPaginationModelImpl();
479        }
480    }
481
482    void setupDataSource()
483    {
484        // TAP5-34: We pass the source into the CachingDataSource now; previously
485        // we were accessing source directly, but during submit the value wasn't
486        // cached, and therefore access was very inefficient, and sorting was
487        // very inconsistent during the processing of the form submission.
488
489        cachingSource = new CachingDataSource(source);
490
491        int availableRows = cachingSource.getAvailableRows();
492
493        if (availableRows == 0)
494            return;
495
496        int maxPage = ((availableRows - 1) / rowsPerPage) + 1;
497
498        // This captures when the number of rows has decreased, typically due to deletions.
499
500        int effectiveCurrentPage = getCurrentPage();
501
502        if (effectiveCurrentPage > maxPage)
503            effectiveCurrentPage = maxPage;
504
505        int startIndex = (effectiveCurrentPage - 1) * rowsPerPage;
506
507        int endIndex = Math.min(startIndex + rowsPerPage - 1, availableRows - 1);
508
509        dataModel = null;
510
511        cachingSource.prepare(startIndex, endIndex, sortModel.getSortConstraints());
512    }
513
514    Object beginRender(MarkupWriter writer)
515    {
516        // Skip rendering of component (template, body, etc.) when there's nothing to display.
517        // The empty placeholder will already have rendered.
518
519        if (cachingSource.getAvailableRows() == 0)
520            return !renderTableIfEmpty ? false : null;
521
522        if (inPlace && zone == null)
523        {
524            javaScriptSupport.require("t5/core/zone");
525
526            writer.element("div", "data-container-type", "zone");
527
528            didRenderZoneDiv = true;
529
530            // Through Tapestry 5.3, we had a specific id for the zone that had to be passed down to the
531            // GridPager and etc.  That's no longer necessary, so zone will always be null or "^".  We don't
532            // even need any special ids to be allocated!
533            zone = "^";
534        }
535
536        return null;
537    }
538
539    void afterRender(MarkupWriter writer)
540    {
541        if (didRenderZoneDiv)
542        {
543            writer.end(); // div
544            didRenderZoneDiv = false;
545        }
546    }
547
548    public BeanModel getDataModel()
549    {
550        if (dataModel == null)
551        {
552            dataModel = model;
553
554            BeanModelUtils.modify(dataModel, add, include, exclude, reorder);
555        }
556
557        return dataModel;
558    }
559
560    public int getNumberOfProperties()
561    {
562        return getDataModel().getPropertyNames().size();
563    }
564
565    public GridDataSource getDataSource()
566    {
567        return cachingSource;
568    }
569
570    public GridSortModel getSortModel()
571    {
572        return sortModel;
573    }
574
575    public Object getPagerTop()
576    {
577        return pagerPosition.isMatchTop() ? pager : null;
578    }
579
580    public Object getPagerBottom()
581    {
582        return pagerPosition.isMatchBottom() ? pager : null;
583    }
584
585    public int getCurrentPage()
586    {
587        Integer currentPage = paginationModel.getCurrentPage();
588
589        return currentPage == null ? 1 : currentPage;
590    }
591
592    public void setCurrentPage(int currentPage)
593    {
594        paginationModel.setCurrentPage(currentPage);
595    }
596
597    private boolean getSortAscending()
598    {
599        Boolean sortAscending = paginationModel.getSortAscending();
600
601        return sortAscending != null && sortAscending.booleanValue();
602    }
603
604    private void setSortAscending(boolean sortAscending)
605    {
606        paginationModel.setSortAscending(sortAscending);
607    }
608
609    public int getRowsPerPage()
610    {
611        return rowsPerPage;
612    }
613
614    public Object getRow()
615    {
616        return row;
617    }
618
619    public void setRow(Object row)
620    {
621        this.row = row;
622    }
623
624    /**
625     * Resets the Grid to inital settings; this sets the current page to one, and
626     * {@linkplain org.apache.tapestry5.grid.GridSortModel#clear() clears the sort model}.
627     */
628    public void reset()
629    {
630        setCurrentPage(1);
631        sortModel.clear();
632    }
633
634    /**
635     * Event handler for inplaceupdate event triggered from nested components when an Ajax update occurs. The event
636     * context will carry the zone, which is recorded here, to allow the Grid and its sub-components to properly
637     * re-render themselves. Invokes
638     * {@link org.apache.tapestry5.services.ComponentEventResultProcessor#processResultValue(Object)} passing this (the
639     * Grid component) as the content provider for the update.
640     */
641    void onInPlaceUpdate() throws IOException
642    {
643        this.zone = "^";
644
645        componentEventResultProcessor.processResultValue(this);
646    }
647
648    public String getClientId()
649    {
650        return table.getClientId();
651    }
652}