    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
    459        setupPaginationModel();
    460
    461        if (formSupport != null)
    462        {
    463            formSupport.store(this, SETUP_DATA_SOURCE);
    464        }
    465
    466        setupDataSource();
    467
    468        // If there's no rows, display the empty block placeholder.
    469
    470        return !renderTableIfEmpty && cachingSource.getAvailableRows() == 0 ? empty : null;
    471    }
    472
    473    void cleanupRender()
    474    {
    475        // if an inPlace Grid is rendered inside a Loop, be sure to generate a new wrapper
    476        // zone for each iteration (TAP5-2256)
    477        zone = null;
    478    }
    479
    480    private void setupPaginationModel()
    481    {
    482        if (paginationModel == null)
    483        {
    484            paginationModel = new GridPaginationModelImpl();
    485        }
    486    }
    487
    488    void setupDataSource()
    489    {
    490        // TAP5-34: We pass the source into the CachingDataSource now; previously
    491        // we were accessing source directly, but during submit the value wasn't
    492        // cached, and therefore access was very inefficient, and sorting was
    493        // very inconsistent during the processing of the form submission.
    494
    495        cachingSource = new CachingDataSource(source);
    496
    497        int availableRows = cachingSource.getAvailableRows();
    498
    499        if (availableRows == 0)
    500            return;
    501
    502        int maxPage = ((availableRows - 1) / rowsPerPage) + 1;
    503
    504        // This captures when the number of rows has decreased, typically due to deletions.
    505
    506        int effectiveCurrentPage = getCurrentPage();
    507
    508        if (effectiveCurrentPage > maxPage)
    509            effectiveCurrentPage = maxPage;
    510
    511        int startIndex = (effectiveCurrentPage - 1) * rowsPerPage;
    512
    513        int endIndex = Math.min(startIndex + rowsPerPage - 1, availableRows - 1);
    514
    515        dataModel = null;
    516
    517        cachingSource.prepare(startIndex, endIndex, sortModel.getSortConstraints());
    518    }
    519
    520    Object beginRender(MarkupWriter writer)
    521    {
    522        // Skip rendering of component (template, body, etc.) when there's nothing to display.
    523        // The empty placeholder will already have rendered.
    524
    525        if (cachingSource.getAvailableRows() == 0)
    526            return !renderTableIfEmpty ? false : null;
    527
    528        if (inPlace && zone == null)
    529        {
    530            javaScriptSupport.require("t5/core/zone");
    531
    532            writer.element("div", "data-container-type", "zone");
    533
    534            didRenderZoneDiv = true;
    535
    536            // Through Tapestry 5.3, we had a specific id for the zone that had to be passed down to the
    537            // GridPager and etc.  That's no longer necessary, so zone will always be null or "^".  We don't
    538            // even need any special ids to be allocated!
    539            zone = "^";
    540        }
    541
    542        return null;
    543    }
    544
    545    void afterRender(MarkupWriter writer)
    546    {
    547        if (didRenderZoneDiv)
    548        {
    549            writer.end(); // div
    550            didRenderZoneDiv = false;
    551        }
    552    }
    553
    554    public BeanModel getDataModel()
    555    {
    556        if (dataModel == null)
    557        {
    558            dataModel = model;
    559
    560            BeanModelUtils.modify(dataModel, add, include, exclude, reorder);
    561        }
    562
    563        return dataModel;
    564    }
    565
    566    public int getNumberOfProperties()
    567    {
    568        return getDataModel().getPropertyNames().size();
    569    }
    570
    571    public GridDataSource getDataSource()
    572    {
    573        return cachingSource;
    574    }
    575
    576    public GridSortModel getSortModel()
    577    {
    578        return sortModel;
    579    }
    580
    581    public Object getPagerTop()
    582    {
    583        return pagerPosition.isMatchTop() ? pager : null;
    584    }
    585
    586    public Object getPagerBottom()
    587    {
    588        return pagerPosition.isMatchBottom() ? pager : null;
    589    }
    590
    591    public int getCurrentPage()
    592    {
    593        Integer currentPage = paginationModel.getCurrentPage();
    594
    595        return currentPage == null ? 1 : currentPage;
    596    }
    597
    598    public void setCurrentPage(int currentPage)
    599    {
    600        paginationModel.setCurrentPage(currentPage);
    601    }
    602
    603    private boolean getSortAscending()
    604    {
    605        Boolean sortAscending = paginationModel.getSortAscending();
    606
    607        return sortAscending != null && sortAscending.booleanValue();
    608    }
    609
    610    private void setSortAscending(boolean sortAscending)
    611    {
    612        paginationModel.setSortAscending(sortAscending);
    613    }
    614
    615    public int getRowsPerPage()
    616    {
    617        return rowsPerPage;
    618    }
    619
    620    public Object getRow()
    621    {
    622        return row;
    623    }
    624
    625    public void setRow(Object row)
    626    {
    627        this.row = row;
    628    }
    629
    630    /**
    631     * Resets the Grid to inital settings; this sets the current page to one, and
    632     * {@linkplain org.apache.tapestry5.grid.GridSortModel#clear() clears the sort model}.
    633     */
    634    public void reset()
    635    {
    636        setCurrentPage(1);
    637        sortModel.clear();
    638    }
    639
    640    /**
    641     * Event handler for inplaceupdate event triggered from nested components when an Ajax update occurs. The event
    642     * context will carry the zone, which is recorded here, to allow the Grid and its sub-components to properly
    643     * re-render themselves. Invokes
    644     * {@link org.apache.tapestry5.services.ComponentEventResultProcessor#processResultValue(Object)} passing this (the
    645     * Grid component) as the content provider for the update.
    646     */
    647    void onInPlaceUpdate() throws IOException
    648    {
    649        this.zone = "^";
    650
    651        componentEventResultProcessor.processResultValue(this);
    652    }
    653
    654    public String getClientId()
    655    {
    656        return table.getClientId();
    657    }
    658}