// effects: Given the cells for the extent (extentCells) along with
// the signatures (multiconstants + needed attributes) for this extent, generates
// the left cell wrappers for it extent (viewTarget indicates whether
// the view is for querying or update purposes
// Modifies m_cellWrappers to contain this list
private bool CreateLeftCellWrappers(IList <Cell> extentCells, ViewTarget viewTarget)
{
var alignedCells = AlignFields(extentCells, m_memberMaps.ProjectedSlotMap, viewTarget);
Debug.Assert(alignedCells.Count == extentCells.Count, "Cell counts disagree");
// Go through all the cells and create cell wrappers that can be used for generating the view
m_cellWrappers = new List <LeftCellWrapper>();
for (var i = 0; i < alignedCells.Count; i++)
{
var alignedCell = alignedCells[i];
var left = alignedCell.GetLeftQuery(viewTarget);
var right = alignedCell.GetRightQuery(viewTarget);
// Obtain the non-null projected slots into attributes
var attributes = left.GetNonNullSlots();
var fromVariable = BoolExpression.CreateLiteral(
new CellIdBoolean(m_identifiers, extentCells[i].CellNumber), m_memberMaps.LeftDomainMap);
var leftFragmentQuery = FragmentQuery.Create(fromVariable, left);
if (viewTarget == ViewTarget.UpdateView)
{
leftFragmentQuery = m_leftFragmentQP.CreateDerivedViewBySelectingConstantAttributes(leftFragmentQuery)
?? leftFragmentQuery;
}
var leftWrapper = new LeftCellWrapper(
m_viewTarget, attributes, leftFragmentQuery, left, right, m_memberMaps,
extentCells[i]);
m_cellWrappers.Add(leftWrapper);
}
return(true);
}
