Bug 199028 A problem with dataset valid check
Description: There is a sample datasource and dataset, delete the datasource, the dataset will be invalid. Then create a datasource like the previous one, the dataset still does not work. Build version:2.2.0.v20070807-0630 Steps to reproduce: 1. Create a sample datasource and dataset. 2. Delete the datasource, and the dataset will be invalid. 3. Create a sample datasource again, with the same name as the deleted one. 4. Double click on the dataset, error pops "The datasource of this dataset is missing". Expected result: The dataset shall be refer to the same name datasource. Actual result: If remove a datasource, the related datasets will not workable and repairable.
UI/org.eclipse.birt.report.designer.ui.views/src/org/eclipse/birt/report/designer/internal/ui/views/data/providers/DataSetNodeProvider.java
}
	/**
	 * Gets the children element of the given model using visitor.
	 * 
	 * @param object
	 *            the handle
	 */
	public Object[] getChildren( Object object )
	{
		DataSetHandle handle = (DataSetHandle) object;
		ArrayList params = new ArrayList( 10 );
		CachedMetaDataHandle cmdh = null;
		try
		{
			cmdh = DataSetUIUtil.getCachedMetaDataHandle( handle );
		}
		catch ( SemanticException e )
		{
		}
		ArrayList columns = new ArrayList( 10 );
		if ( cmdh != null )
		{
			for ( Iterator iterator = cmdh.getResultSet( ).iterator( ); iterator.hasNext( ); )
			{
				ResultSetColumnHandle element = (ResultSetColumnHandle) iterator.next( );
				columns.add( element );
			}
		}
		PropertyHandle parameters = handle.getPropertyHandle( DataSetHandle.PARAMETERS_PROP );
		Iterator iter = parameters.iterator( );