public static IQueryable OrderBy(this IQueryable source, string ordering, params object[] values)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (ordering == null)
{
throw new ArgumentNullException("ordering");
}
var resolver = new MapIdentifierResolver();
resolver.AddPositionalArguments(values);
var parser = new ExpressionParser(ordering, resolver, source.ElementType);
IEnumerable <DynamicOrdering> orderings = parser.ParseOrdering();
Expression queryExpr = source.Expression;
string methodAsc = "OrderBy";
string methodDesc = "OrderByDescending";
foreach (DynamicOrdering o in orderings)
{
queryExpr = Expression.Call(
typeof(Queryable), o.Ascending ? methodAsc : methodDesc,
new Type[] { source.ElementType, o.Selector.Type },
queryExpr, Expression.Quote(Expression.Lambda(o.Selector, parser.IteratorParameter)));
methodAsc = "ThenBy";
methodDesc = "ThenByDescending";
}
return(source.Provider.CreateQuery(queryExpr));
}
public static LambdaExpression ParseLambda(Type itType, Type resultType, string expression, params object[] values)
{
var resolver = new MapIdentifierResolver();
resolver.AddPositionalArguments(values);
return(ParseLambda(itType, resultType, expression, resolver));
}
public static LambdaExpression ParseLambda(Type resultType, string expression, params object[] values)
{
var resolver = new MapIdentifierResolver();
resolver.AddPositionalArguments(values);
var parser = new ExpressionParser(expression, resolver);
return(Expression.Lambda(parser.Parse(resultType)));
}
