public override LambdaExpression VisitValPathExp(ScimFilterParser.ValPathExpContext context)
{
// brackets MAY change the field type (TResource) thus, the expression within the brackets
// should be visited in context of the new field's type
var argument = Expression.Parameter(typeof(TResource));
var attrPathExpression = Visit(context.attrPath());
if (attrPathExpression.ReturnType != typeof(TResource))
{
Type childFilterType = attrPathExpression.ReturnType;
bool isEnumerable = childFilterType.IsNonStringEnumerable();
if (isEnumerable)
{
childFilterType = childFilterType.GetGenericArguments()[0]; // set childFilterType to enumerable type argument
}
var childVisitorType = typeof(ScimFilterVisitor <>).MakeGenericType(childFilterType);
var childVisitor = (IScimFilterVisitor)childVisitorType.CreateInstance(ServerConfiguration);
var childLambda = childVisitor.VisitExpression(context.valPathFilter()); // Visit the nested filter expression.
var childLambdaArgument = Expression.TryCatch(
Expression.Block(Expression.Invoke(attrPathExpression, argument)),
Expression.Catch(typeof(Exception),
Expression.Constant(attrPathExpression.ReturnType.GetDefaultValue(), attrPathExpression.ReturnType))
);
if (isEnumerable)
{
// if we have an enumerable, then we need to see if any of its elements satisfy the childLambda
// to accomplish this, let's just make use of .NET's Any<TSource>(enumerable, predicate)
var anyMethod = MethodCache["any"].MakeGenericMethod(childFilterType);
var anyPredicate = Expression.TryCatch(
Expression.Block(
Expression.Call(
anyMethod,
new List <Expression>
{
childLambdaArgument,
childLambda
})),
Expression.Catch(typeof(ArgumentNullException), Expression.Constant(false)));
return(Expression.Lambda(anyPredicate, argument));
}
return(Expression.Lambda(
Expression.Invoke(
childLambda,
Expression.Invoke(attrPathExpression, argument)),
argument));
}
// TODO: (DG) This is probably incorrect if the property is nested and the same type as its parent.
// We'll most likely still need a childLambda.
return(Visit(context.valPathFilter()));
}
public override LambdaExpression VisitValPathExp(ScimFilterParser.ValPathExpContext context)
{
// brackets MAY change the field type (TResource) thus, the expression within the brackets
// should be visited in context of the new field's type
var propertyNameToken = context.FIELD().GetText();
var property = PropertyCache
.GetOrAdd(
typeof(TResource),
type =>
type.GetProperties(BindingFlags.Public | BindingFlags.Instance)
.ToDictionary(pi => pi.Name, pi => pi, StringComparer.OrdinalIgnoreCase))[propertyNameToken];
if (property == null)
{
throw new Exception("ERROR"); // TODO: (DG) make proper error
}
if (property.PropertyType != typeof(TResource))
{
bool isEnumerable = property.PropertyType.IsNonStringEnumerable();
Type childFilterType = property.PropertyType;
if (isEnumerable)
{
childFilterType = childFilterType.GetGenericArguments()[0]; // set childFilterType to enumerable type argument
}
var argument = Expression.Parameter(typeof(TResource));
var childVisitorType = typeof(ScimFilterVisitor <>).MakeGenericType(childFilterType);
var childVisitor = (IScimFilterVisitor)childVisitorType.CreateInstance();
var childLambda = childVisitor.VisitExpression(context.valPathFilter()); // Visit the nested filter expression.
var childLambdaArgument = Expression.TryCatch(
Expression.Block(Expression.Property(argument, property)),
Expression.Catch(typeof(Exception),
Expression.Constant(property.PropertyType.GetDefaultValue(), property.PropertyType))
);
if (isEnumerable)
{
// if we have an enumerable, then we need to see if any of its elements satisfy the childLambda
// to accomplish this, let's just make use of .NET's Any<TSource>(enumerable, predicate)
var anyMethod = MethodCache["any"].MakeGenericMethod(childFilterType);
var anyPredicate = Expression.TryCatch(
Expression.Block(
Expression.Call(
anyMethod,
new List <Expression>
{
childLambdaArgument,
childLambda
})),
Expression.Catch(typeof(ArgumentNullException), Expression.Constant(false)));
return(Expression.Lambda(anyPredicate, argument));
}
return(Expression.Lambda(
Expression.Invoke(
childLambda,
new List <Expression>
{
Expression.TypeAs(childLambdaArgument, childFilterType)
}),
argument));
}
// TODO: (DG) This is probably incorrect if the property is nested and the same type as its parent.
// We'll most likely still need a childLambda.
return(Visit(context.valPathFilter()));
}