private static MethodInfo GetOrderByMethod(bool isThenBy, bool isDesc, Type elementType, Type nextExprType)
{
MethodInfo orderByMethod;
if (isThenBy)
{
orderByMethod = isDesc
? TypeFns.GetMethodByExample(
(IOrderedQueryable <String> q) => q.ThenByDescending(s => s.Length),
elementType, nextExprType)
: TypeFns.GetMethodByExample(
(IOrderedQueryable <String> q) => q.ThenBy(s => s.Length),
elementType, nextExprType);
}
else
{
orderByMethod = isDesc
? TypeFns.GetMethodByExample(
(IQueryable <String> q) => q.OrderByDescending(s => s.Length),
elementType, nextExprType)
: TypeFns.GetMethodByExample(
(IQueryable <String> q) => q.OrderBy(s => s.Length),
elementType, nextExprType);
}
return(orderByMethod);
}
public static Func <IQueryable, IQueryable> BuildSelectFunc(Type elementType, List <String> selectClauses)
{
var propSigs = selectClauses.Select(sc => new PropertySignature(elementType, sc)).ToList();
var dti = DynamicTypeInfo.FindOrCreate(propSigs.Select(ps => ps.Name), propSigs.Select(ps => ps.ReturnType));
var lambdaExpr = CreateNewLambda(dti, propSigs);
var method = TypeFns.GetMethodByExample((IQueryable <String> q) => q.Select(s => s.Length), elementType, dti.DynamicType);
var func = BuildIQueryableFunc(elementType, method, lambdaExpr);
return(func);
}
