// Copyright 2007 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.tapestry.corelib.components;
import java.util.List;
import org.apache.tapestry.ComponentAction;
import org.apache.tapestry.annotations.Environmental;
import org.apache.tapestry.annotations.Parameter;
import org.apache.tapestry.beaneditor.PropertyModel;
import org.apache.tapestry.grid.GridDataSource;
import org.apache.tapestry.grid.GridModelProvider;
import org.apache.tapestry.services.FormSupport;
/**
* Renders out a series of rows within the table.
* <p>
* Inside a {@link Form}, a series of row index numbers are stored into the form (
* {@linkplain FormSupport#store(Object, ComponentAction) as ComponentActions}). This is not ideal
* ... in a situation where the data set can shift between the form render and the form submission,
* this can cause unexpected results, including applying changes to the wrong objects.
*/
public class GridRows
{
static class SetupForRow implements ComponentAction<GridRows>
{
private static final long serialVersionUID = -3216282071752371975L;
private final int _rowIndex;
public SetupForRow(int rowIndex)
{
_rowIndex = rowIndex;
}
public void execute(GridRows component)
{
component.setupForRow(_rowIndex);
}
};
/**
* Parameter used to set the CSS class for each row (each <tr> element) within the
* <tbody>). This is not cached, so it will be recomputed for each row.
*/
@Parameter(cache = false)
private String _rowClass;
/** Object that provides access to the bean and data models used to render the Grid. */
@Parameter(value = "componentResources.container")
private GridModelProvider _provider;
/** Number of rows displayed on each page. Long result sets are split across multiple pages. */
@Parameter(required = true)
private int _rowsPerPage;
/** The current page number within the available pages (indexed from 1). */
@Parameter(required = true)
private int _currentPage;
/**
* The current row being rendered, this is primarily an output parameter used to allow the Grid,
* and the Grid's container, to know what object is being rendered.
*/
@Parameter(required = true)
private Object _row;
/**
* If true and the Loop is enclosed by a Form, then the normal state saving logic is turned off.
* Defaults to false, enabling state saving logic within Forms.
*/
@SuppressWarnings("unused")
@Parameter
private boolean _volatile;
@Environmental(false)
private FormSupport _formSupport;
private boolean _recordingStateInsideForm;
private int _startRow;
private int _endRow;
private int _rowIndex;
private String _propertyName;
private PropertyModel _columnModel;
public String getRowClass()
{
return _rowClass;
}
public String getCellClass()
{
String id = _provider.getDataModel().get(_propertyName).getId();
return id + "-cell";
}
void setupRender()
{
GridDataSource dataSource = _provider.getDataSource();
int availableRows = dataSource.getAvailableRows();
int maxPages = ((availableRows - 1) / _rowsPerPage) + 1;
// This can sometimes happen when the number of items shifts between requests.
if (_currentPage > maxPages) _currentPage = maxPages;
_startRow = (_currentPage - 1) * _rowsPerPage;
_endRow = Math.min(availableRows - 1, _startRow + _rowsPerPage - 1);
_rowIndex = _startRow;
_recordingStateInsideForm = !_volatile && _formSupport != null;
}
/**
* Callback method, used when recording state to a form, or called directly when not recording
* state.
*/
void setupForRow(int rowIndex)
{
_row = _provider.getDataSource().getRowValue(rowIndex);
}
void beginRender()
{
// When needed, store a callback used when the form is submitted.
if (_recordingStateInsideForm) _formSupport.store(this, new SetupForRow(_rowIndex));
// And do it now for the render.
setupForRow(_rowIndex);
}
boolean afterRender()
{
_rowIndex++;
return _rowIndex > _endRow;
}
public List<String> getPropertyNames()
{
return _provider.getDataModel().getPropertyNames();
}
public String getPropertyName()
{
return _propertyName;
}
public void setPropertyName(String propertyName)
{
_propertyName = propertyName;
_columnModel = _provider.getDataModel().get(propertyName);
}
public Object getRow()
{
return _row;
}
public PropertyModel getColumnModel()
{
return _columnModel;
}
}