    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    @Property(write = false)
    177    private Block empty;
    178
    179    /**
    180     * CSS class for the &lt;table&gt; element. In addition, informal parameters to the Grid are rendered in the table
    181     * element.
    182     */
    183    @Parameter(name = "class", defaultPrefix = BindingConstants.LITERAL,
    184            value = BindingConstants.SYMBOL + ":" + ComponentParameterConstants.GRID_TABLE_CSS_CLASS)
    185    @Property(write = false)
    186    private String tableClass;
    187
    188    /**
    189     * If true, then the Grid will be wrapped in an element that acts like a
    190     * {@link org.apache.tapestry5.corelib.components.Zone}; all the paging and sorting links will refresh the zone,
    191     * repainting the entire grid within it, but leaving the rest of the page (outside the zone) unchanged.
    192     */
    193    @Parameter
    194    private boolean inPlace;
    195
    196    /**
    197     * If true, then the Grid will also render a table element complete with headers if the data source is empty.
    198     * If set to true, a model parameter will have to be specified. A default model for a specific class can be
    199     * created using {@link BeanModelSource#createDisplayModel(Class, org.apache.tapestry5.ioc.Messages)}.
    200     */
    201    @Parameter
    202    private boolean renderTableIfEmpty = false;
    203
    204
    205    /**
    206     * The name of the pseudo-zone that encloses the Grid. Starting in 5.4, this is always either
    207     * null or "^" and is not really used the way it was in 5.3; instead it triggers the addition
    208     * of a {@code data-inplace-grid-links} attribute in a div surrounding any links related to
    209     * sorting or pagination. The rest is sorted out on the client. See module {@code t5/core/zone}.
    210     */
    211    @Property(write = false)
    212    private String zone;
    213
    214    private boolean didRenderZoneDiv;
    215
    216
    217    /**
    218     * The pagination model for the Grid, which encapsulates current page, sort column id,
    219     * and sort ascending/descending. If not bound, a persistent property of the Grid is used.
    220     * When rendering the Grid in a loop, this should be bound in some way to keep successive instances
    221     * of the Grid configured individually.
    222     *
    223     * @since 5.4
    224     */
    225    @Parameter(value = "defaultPaginationModel")
    226    private GridPaginationModel paginationModel;
    227
    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            if (columnId.equals(paginationModel.getSortColumnId()))
    356            {
    357                setSortAscending(!getSortAscending());
    358                return;
    359            }
    360
    361            paginationModel.setSortColumnId(columnId);
    362            setSortAscending(true);
    363        }
    364
    365        public List<SortConstraint> getSortConstraints()
    366        {
    367            // In a few limited cases we may not have yet hit the SetupRender phase, and the model may be null.
    368            if (paginationModel == null || paginationModel.getSortColumnId() == null)
    369            {
    370                return Collections.emptyList();
    371            }
    372
    373            PropertyModel sortModel = getDataModel().getById(paginationModel.getSortColumnId());
    374
    375            SortConstraint constraint = new SortConstraint(sortModel, getColumnSort());
    376
    377            return Collections.singletonList(constraint);
    378        }
    379
    380        public void clear()
    381        {
    382            paginationModel.setSortColumnId(null);
    383            paginationModel.setSortAscending(null);
    384        }
    385    }
    386
    387    GridSortModel defaultSortModel()
    388    {
    389        return new DefaultGridSortModel();
    390    }
    391
    392    /**
    393     * Returns a {@link org.apache.tapestry5.Binding} instance that attempts to identify the model from the source
    394     * parameter (via {@link org.apache.tapestry5.grid.GridDataSource#getRowType()}. Subclasses may override to provide
    395     * a different mechanism. The returning binding is variant (not invariant).
    396     *
    397     * @see BeanModelSource#createDisplayModel(Class, org.apache.tapestry5.ioc.Messages)
    398     */
    399    protected Binding defaultModel()
    400    {
    401
    402        return new AbstractBinding()
    403        {
    404            public Object get()
    405            {
    406                // Get the default row type from the data source
    407
    408                GridDataSource gridDataSource = source;
    409
    410                Class rowType = gridDataSource.getRowType();
    411
    412                if (renderTableIfEmpty || rowType == null)
    413                    throw new RuntimeException(
    414                            String.format(
    415                                    "Unable to determine the bean type for rows from %s. You should bind the model parameter explicitly.",
    416                                    gridDataSource));
    417
    418                // Properties do not have to be read/write
    419
    420                return modelSource.createDisplayModel(rowType, overrides.getOverrideMessages());
    421            }
    422
    423            /**
    424             * Returns false. This may be overkill, but it basically exists because the model is
    425             * inherently mutable and therefore may contain client-specific state and needs to be
    426             * discarded at the end of the request. If the model were immutable, then we could leave
    427             * invariant as true.
    428             */
    429            @Override
    430            public boolean isInvariant()
    431            {
    432                return false;
    433            }
    434        };
    435    }
    436
    437    static final ComponentAction<Grid> SETUP_DATA_SOURCE = new ComponentAction<Grid>()
    438    {
    439        private static final long serialVersionUID = 8545187927995722789L;
    440
    441        public void execute(Grid component)
    442        {
    443            component.setupDataSource();
    444        }
    445
    446        @Override
    447        public String toString()
    448        {
    449            return "Grid.SetupDataSource";
    450        }
    451    };
    452
    453    Object setupRender()
    454    {
    455        if (formSupport != null)
    456        {
    457            formSupport.store(this, SETUP_DATA_SOURCE);
    458        }
    459
    460        setupDataSource();
    461
    462        // If there's no rows, display the empty block placeholder.
    463
    464        return !renderTableIfEmpty && cachingSource.getAvailableRows() == 0 ? empty : null;
    465    }
    466
    467    void cleanupRender()
    468    {
    469        // if an inPlace Grid is rendered inside a Loop, be sure to generate a new wrapper
    470        // zone for each iteration (TAP5-2256)
    471        zone = null;
    472
    473        // If grid is rendered inside a Loop. be sure to generate a new data model for
    474        // each iteration (TAP5-2470)
    475        dataModel = null;
    476    }
    477
    478    public GridPaginationModel getDefaultPaginationModel()
    479    {
    480        if (defaultPaginationModel == null)
    481        {
    482            defaultPaginationModel = new GridPaginationModelImpl();
    483        }
    484
    485        return defaultPaginationModel;
    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        cachingSource.prepare(startIndex, endIndex, sortModel.getSortConstraints());
    516    }
    517
    518    Object beginRender(MarkupWriter writer)
    519    {
    520        // Skip rendering of component (template, body, etc.) when there's nothing to display.
    521        // The empty placeholder will already have rendered.
    522
    523        if (cachingSource.getAvailableRows() == 0)
    524            return !renderTableIfEmpty ? false : null;
    525
    526        if (inPlace && zone == null)
    527        {
    528            javaScriptSupport.require("t5/core/zone");
    529
    530            writer.element("div", "data-container-type", "zone");
    531
    532            didRenderZoneDiv = true;
    533
    534            // Through Tapestry 5.3, we had a specific id for the zone that had to be passed down to the
    535            // GridPager and etc.  That's no longer necessary, so zone will always be null or "^".  We don't
    536            // even need any special ids to be allocated!
    537            zone = "^";
    538        }
    539
    540        return null;
    541    }
    542
    543    void afterRender(MarkupWriter writer)
    544    {
    545        if (didRenderZoneDiv)
    546        {
    547            writer.end(); // div
    548            didRenderZoneDiv = false;
    549        }
    550    }
    551
    552    public BeanModel getDataModel()
    553    {
    554        if (dataModel == null)
    555        {
    556            dataModel = model;
    557
    558            BeanModelUtils.modify(dataModel, add, include, exclude, reorder);
    559        }
    560
    561        return dataModel;
    562    }
    563
    564    public int getNumberOfProperties()
    565    {
    566        return getDataModel().getPropertyNames().size();
    567    }
    568
    569    public GridDataSource getDataSource()
    570    {
    571        return cachingSource;
    572    }
    573
    574    public GridSortModel getSortModel()
    575    {
    576        return sortModel;
    577    }
    578
    579    public Object getPagerTop()
    580    {
    581        return pagerPosition.isMatchTop() ? pager : null;
    582    }
    583
    584    public Object getPagerBottom()
    585    {
    586        return pagerPosition.isMatchBottom() ? pager : null;
    587    }
    588
    589    public int getCurrentPage()
    590    {
    591        Integer currentPage = paginationModel.getCurrentPage();
    592
    593        return currentPage == null ? 1 : currentPage;
    594    }
    595
    596    public void setCurrentPage(int currentPage)
    597    {
    598        paginationModel.setCurrentPage(currentPage);
    599    }
    600
    601    private boolean getSortAscending()
    602    {
    603        Boolean sortAscending = paginationModel.getSortAscending();
    604
    605        return sortAscending != null && sortAscending.booleanValue();
    606    }
    607
    608    private void setSortAscending(boolean sortAscending)
    609    {
    610        paginationModel.setSortAscending(sortAscending);
    611    }
    612
    613    public int getRowsPerPage()
    614    {
    615        return rowsPerPage;
    616    }
    617
    618    public Object getRow()
    619    {
    620        return row;
    621    }
    622
    623    public void setRow(Object row)
    624    {
    625        this.row = row;
    626    }
    627
    628    /**
    629     * Resets the Grid to inital settings; this sets the current page to one, and
    630     * {@linkplain org.apache.tapestry5.grid.GridSortModel#clear() clears the sort model}.
    631     */
    632    public void reset()
    633    {
    634        sortModel.clear();
    635        setCurrentPage(1);
    636    }
    637
    638    /**
    639     * Event handler for inplaceupdate event triggered from nested components when an Ajax update occurs. The event
    640     * context will carry the zone, which is recorded here, to allow the Grid and its sub-components to properly
    641     * re-render themselves. Invokes
    642     * {@link org.apache.tapestry5.services.ComponentEventResultProcessor#processResultValue(Object)} passing this (the
    643     * Grid component) as the content provider for the update.
    644     */
    645    void onInPlaceUpdate() throws IOException
    646    {
    647        this.zone = "^";
    648
    649        componentEventResultProcessor.processResultValue(this);
    650    }
    651
    652    public String getClientId()
    653    {
    654        return table.getClientId();
    655    }
    656}