protected override OrderByQueryPart Parse(string parameterValue)
{
// TODO: support complex order by expressions (e.g. "$orderby=(Id mod 3) desc")
var matches = Regex.Matches(parameterValue, @"(\w+)\s+(asc|desc)", RegexOptions.IgnoreCase).Cast <Match>();
var orderings = new List <ODataOrdering>();
foreach (var match in matches)
{
var groups = match.Groups.Cast <Group>().Skip(1).ToList();
var property = groups[0].Value;
var dir = groups[1].Value;
ODataOrderingDirection direction;
if (Enum.TryParse(dir, true, out direction) == false)
{
// TODO: I'm pretty sure this branch will never be taken, but...
throw new ArgumentException(String.Format("'{0}' is not a valid ordering direction.", dir));
}
orderings.Add(ODataQueryPart.Ordering(property, direction));
}
return(ODataQueryPart.OrderBy(orderings.ToArray()));
}
public override void VisitOrdering(Ordering ordering, QueryModel queryModel, OrderByClause orderByClause, int index)
{
if (_query.OrderByPredicate == null)
{
_query.OrderByPredicate = ODataQueryPart.OrderBy();
}
if (ordering.Expression.NodeType == ExpressionType.MemberAccess)
{
var memberExpression = (MemberExpression)ordering.Expression;
var direction = (ordering.OrderingDirection == OrderingDirection.Asc)
? ODataOrderingDirection.Asc
: ODataOrderingDirection.Desc;
var o = ODataQueryPart.Ordering(memberExpression.Member.Name, direction);
_query.OrderByPredicate.AddOrdering(o);
}
base.VisitOrdering(ordering, queryModel, orderByClause, index);
}
