/// <summary>
/// Retrieves a subset of rows with the pending updates applied. If more rows than exist
/// are requested, only the rows that exist will be returned.
/// </summary>
/// <param name="startIndex">Index to start returning rows from</param>
/// <param name="rowCount">The number of rows to return.</param>
/// <returns>An array of rows with pending edits applied</returns>
public async Task <EditRow[]> GetRows(long startIndex, int rowCount)
{
ThrowIfNotInitialized();
// Get the cached rows from the result set
ResultSetSubset cachedRows = startIndex < associatedResultSet.RowCount
? await associatedResultSet.GetSubset(startIndex, rowCount)
: new ResultSetSubset
{
RowCount = 0,
Rows = new DbCellValue[][] { }
};
// Convert the rows into EditRows and apply the changes we have
List <EditRow> editRows = new List <EditRow>();
for (int i = 0; i < cachedRows.RowCount; i++)
{
long rowId = i + startIndex;
RowEditBase edr;
if (EditCache.TryGetValue(rowId, out edr))
{
// Ask the edit object to generate an edit row
editRows.Add(edr.GetEditRow(cachedRows.Rows[i]));
}
else
{
// Package up the existing row into a clean edit row
EditRow er = new EditRow
{
Id = rowId,
Cells = cachedRows.Rows[i].Select(cell => new EditCell(cell, false)).ToArray(),
State = EditRow.EditRowState.Clean
};
editRows.Add(er);
}
}
// If the requested range of rows was at the end of the original cell set and we have
// added new rows, we need to reflect those changes
if (rowCount > cachedRows.RowCount)
{
long endIndex = startIndex + cachedRows.RowCount;
var newRows = EditCache.Where(edit => edit.Key >= endIndex).Take(rowCount - cachedRows.RowCount);
editRows.AddRange(newRows.Select(newRow => newRow.Value.GetEditRow(null)));
}
return(editRows.ToArray());
}
/// <summary>
/// Reverts a cell in a pending edit
/// </summary>
/// <param name="rowId">Internal ID of the row to have its edits reverted</param>
/// <param name="columnId">Ordinal ID of the column to revert</param>
/// <returns>String version of the old value for the cell</returns>
public EditRevertCellResult RevertCell(long rowId, int columnId)
{
ThrowIfNotInitialized();
// Attempt to get the row edit with the given ID
RowEditBase pendingEdit;
if (!EditCache.TryGetValue(rowId, out pendingEdit))
{
throw new ArgumentOutOfRangeException(nameof(rowId), SR.EditDataUpdateNotPending);
}
// Update the row
EditRevertCellResult revertResult = pendingEdit.RevertCell(columnId);
CleanupEditIfRowClean(rowId, revertResult);
// Have the edit base revert the cell
return(revertResult);
}