private void mergeSlice(ElementNavigator snap, ElementNavigator diff)
{
// diff is now located at the first repeat of a slice, which is (possibly) the slice entry
// snap is located at the base definition of the element that will become sliced. But snap is not yet sliced.
// Before we start, is the base element sliceable?
if (!snap.Current.IsRepeating() && !isSlicedToOne(diff.Current))
throw Error.InvalidOperation("The slicing entry in the differential at {0} indicates an unbounded slice, but the base element is not a repeating element",
diff.Current.Path);
Profile.ElementComponent slicingEntry;
// Yes, so, first, add the slicing entry to the snapshot.
if (diff.Current.Slicing != null)
{
slicingEntry = createSliceEntry(snap.Current, diff.Current);
snap.InsertBefore(slicingEntry);
if (!diff.MoveToNext(diff.PathName))
throw Error.InvalidOperation("Slicing has no elements beyond the slicing entry"); // currently impossible to happen
}
else
{
// Mmmm....no slicing entry in the differential. This is only alloweable for extension slices, as a shorthand notation.
if (!snap.Current.IsExtension())
throw Error.InvalidOperation("The slice group at {0} does not start with a slice entry element", diff.Current.Path);
// In this case we insert a "prefab" extension slice.
slicingEntry = createExtensionSlicingEntry(snap.Path, snap.Current);
snap.InsertBefore(slicingEntry);
}
snap.MoveToNext();
// The differential and the snapshot are now both positioned on the first "real" slicing content element
// Start by duplicating the current unsliced base definition as many times as we have slices, so we can
// update these copies for each slice.
var numSlices = countChildNameRepeats(diff);
for (var count = 0; count < numSlices-1; count++) snap.Duplicate();
var slicingName = snap.PathName;
do
{
merge(snap, diff);
}
while (diff.MoveToNext(slicingName) && snap.MoveToNext(slicingName));
//if (slicingEntry.Slicing.Rules != Profile.SlicingRules.Closed)
//{
// // Slices that are open in some form need to repeat the original "base" definition,
// // so that the open slices have a place to "fit in"
// snap.InsertAfter((Profile.ElementComponent)slicingTemplate.DeepCopy());
//}
//TODO: update/check the slice entry's min/max property to match what we've found in the slice group
}