public static Expression FlattenGroupingKey(Expression expression)
{
var visitor = new GroupingKeyFlattener();
expression = visitor.Visit(expression);
if (visitor._flattened)
{
expression = TransparentIdentifierRemovingExpressionVisitor.ReplaceTransparentIdentifiers(expression);
// When the grouping key is an array we have to unwrap it (e.g. group.Key[0] == variable)
if (expression.NodeType == ExpressionType.ArrayIndex &&
expression is BinaryExpression binaryExpression &&
binaryExpression.Left is NewArrayExpression newArray &&
binaryExpression.Right is ConstantExpression indexExpression &&
indexExpression.Value is int index)
{
return newArray.Expressions[index];
}
}
return expression;
}
private static bool TryGetAllMemberMetadata(
Expression expression,
Stack<MemberMetadata> memberPaths,
System.Type convertType,
bool hasIndexer,
out MemberMetadataResult results)
{
expression = GroupingKeyFlattener.FlattenGroupingKey(expression);
var extractor = new MemberMetadataExtractor(memberPaths, convertType, hasIndexer);
extractor.Accept(expression);
results = extractor._entityName != null || extractor._childrenResults.Count > 0
? new MemberMetadataResult(
extractor._childrenResults,
extractor._memberPaths,
extractor._entityName,
extractor._convertType)
: null;
return results != null;
}
