Class NullDataSource
java.lang.Object
org.apache.tapestry5.internal.grid.NullDataSource
- All Implemented Interfaces:
GridDataSource
An implementation of
GridDataSource used when the value null is provided as the
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionintReturns the number of rows available in the data source.Returns the type of value in the rows, or null if not known.getRowValue(int index) Returns the row value at the provided index.voidprepare(int startIndex, int endIndex, List<SortConstraint> sortConstraints) Invoked to allow the source to prepare to present values.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods inherited from interface org.apache.tapestry5.grid.GridDataSource
getAvailableRows, isEmpty
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Constructor Details
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NullDataSource
public NullDataSource()
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Method Details
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getAvailableRows
Description copied from interface:GridDataSourceReturns the number of rows available in the data source.- Specified by:
getAvailableRowsin interfaceGridDataSource
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getRowType
Description copied from interface:GridDataSourceReturns the type of value in the rows, or null if not known. This value is used to create a defaultBeanModelwhen no such model is explicitly provided.- Specified by:
getRowTypein interfaceGridDataSource- Returns:
- the row type, or null
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prepare
Description copied from interface:GridDataSourceInvoked to allow the source to prepare to present values. This gives the source a chance to pre-fetch data (when appropriate) and informs the source of the desired sort order. Sorting comes first, then extraction by range.- Specified by:
preparein interfaceGridDataSource- Parameters:
startIndex- the starting index to be retrievedendIndex- the ending index to be retrievedsortConstraints- identify how data is to be sorted
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getRowValue
Description copied from interface:GridDataSourceReturns the row value at the provided index. This method will be invoked in sequential order. In rare instances,GridDataSource.getAvailableRows()may return a different number of rows than are actually available (i.e., the database was changed between calls toGridDataSource.getAvailableRows()and the call toGridDataSource.prepare(int, int, java.util.List)). In that case, this method should return null for any out-of-range indexes.- Specified by:
getRowValuein interfaceGridDataSource
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