//TODO: compile LINQ expression?
internal IQueryable Where(IQueryable source, IEnumerable <Uri> ids, XmlNamespaceManager namespaceManager = null, IOperatorImplementationProvider operatorImplementationProvider = null)
{
var parameters = new ParameterExpression[] {
Expression.Parameter(source.ElementType)
};
var xpqn = new XPathQueryableNavigator(source.ElementType, namespaceManager);
XPathNodeIterator xpni = xpqn.Select(CoreQueryable.Identifier.Name, namespaceManager);
if (xpni.MoveNext())
{
var idn = (XPathQueryableNavigator)xpni.Current;
Type idType = idn.Type;
TypeConverter converter = GetIdentifierUriConverter(idType);
// Convert ids from Uris to identifier type
// urip => (idType)converter.ConvertTo(urip, idType)
var urip = Expression.Parameter(typeof(Uri));
var conex = Expression.Lambda(
typeof(Func <,>).MakeGenericType(typeof(Uri), idType),
Expression.Convert(
Expression.Call(
Expression.Constant(converter),
"ConvertTo",
null,
urip,
Expression.Constant(idType)
),
idType
),
urip
);
// var convertedIds=ids.Select<Uri, idType>(uri => (idType)converter.ConvertTo(uri, idType))
var urilistp = Expression.Parameter(typeof(IEnumerable <Uri>));
var convertids = Expression.Lambda(
Expression.Call(
typeof(Enumerable),
"Select",
new Type[] { typeof(Uri), idType },
Expression.Constant(ids),
conex
),
urilistp
).Compile();
var convertedIds = convertids.DynamicInvoke(ids);
// Creates the Where clause
LambdaExpression lambda = Expression.Lambda(
Expression.Call(
typeof(Enumerable),
"Contains",
new Type[] { idType },
Expression.Constant(convertedIds),
idn.CreateExpression(parameters[0])
),
parameters
);
return(source.Provider.CreateQuery(
Expression.Call(
typeof(Queryable),
"Where",
new Type[] { source.ElementType },
source.Expression,
Expression.Quote(lambda)
)
));
}
throw new InvalidOperationException();
}
