// public override LambdaExpression VisitNotExp(ScimFilterParser.NotExpContext context)
// {
// var predicate = Visit(context.expression());
// var parameter = Expression.Parameter(typeof(TResource));
// var resultBody = Expression.Not(Expression.Invoke(predicate, parameter));
// return Expression.Lambda<Func<TResource, bool>>(resultBody, parameter);
// }
public override LambdaExpression VisitOperatorExp(ScimFilterParser.OperatorExpContext context)
{
var argument = Expression.Parameter(typeof(TResource));
var attrPathExpression = Visit(context.attrPath());
var operatorToken = context.COMPAREOPERATOR().GetText().ToLower();
var valueToken = context.VALUE().GetText().Trim('"');
var isEnumerable = attrPathExpression.ReturnType.IsNonStringEnumerable();
var left = Expression.TryCatch(
Expression.Block(Expression.Invoke(attrPathExpression, argument)),
Expression.Catch(
typeof(NullReferenceException),
Expression.Constant(attrPathExpression.ReturnType.GetDefaultValue(), attrPathExpression.ReturnType))
);
if (isEnumerable &&
attrPathExpression.ReturnType.IsGenericType &&
typeof(MultiValuedAttribute).IsAssignableFrom(attrPathExpression.ReturnType.GetGenericArguments()[0]))
{
// we're filtering an enumerable of multivaluedattribute without a sub-attribute
// therefore, we default to evaluating the .Value member
var multiValuedAttributeType = attrPathExpression.ReturnType.GetGenericArguments()[0];
var multiValuedAttribute = Expression.Parameter(multiValuedAttributeType);
var valueAttribute = multiValuedAttributeType.GetProperty("Value", BindingFlags.Public | BindingFlags.Instance);
var valueExpression = Expression.TryCatch(
Expression.Block(Expression.Property(multiValuedAttribute, valueAttribute)),
Expression.Catch(
typeof(NullReferenceException),
Expression.Constant(valueAttribute.PropertyType.GetDefaultValue(), valueAttribute.PropertyType))
);
var valueLambda = Expression.Lambda(
CreateBinaryExpression(valueExpression, operatorToken, valueToken),
multiValuedAttribute);
var anyMethod = MethodCache["any"].MakeGenericMethod(multiValuedAttributeType);
var anyPredicate = Expression.TryCatch(
Expression.Block(
Expression.Call(
anyMethod,
new List <Expression>
{
left,
valueLambda
})),
Expression.Catch(typeof(ArgumentNullException), Expression.Constant(false)));
return(Expression.Lambda(anyPredicate, argument));
}
return(Expression.Lambda <Func <TResource, bool> >(
CreateBinaryExpression(left, operatorToken, valueToken),
argument));
}
// public override LambdaExpression VisitNotExp(ScimFilterParser.NotExpContext context)
// {
// var predicate = Visit(context.expression());
// var parameter = Expression.Parameter(typeof(TResource));
// var resultBody = Expression.Not(Expression.Invoke(predicate, parameter));
// return Expression.Lambda<Func<TResource, bool>>(resultBody, parameter);
// }
public override LambdaExpression VisitOperatorExp(ScimFilterParser.OperatorExpContext context)
{
var propertyNameToken = context.FIELD().GetText();
var operatorToken = context.COMPAREOPERATOR().GetText().ToLower();
var valueToken = context.VALUE().GetText().Trim('"');
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
}
var isEnumerable = property.PropertyType.IsNonStringEnumerable();
var argument = Expression.Parameter(typeof(TResource));
var left = Expression.TryCatch(
Expression.Block(Expression.Property(argument, property)),
Expression.Catch(
typeof(NullReferenceException),
Expression.Constant(property.PropertyType.GetDefaultValue(), property.PropertyType))
);
if (isEnumerable &&
property.PropertyType.IsGenericType &&
typeof(MultiValuedAttribute).IsAssignableFrom(property.PropertyType.GetGenericArguments()[0]))
{
// we're filtering an enumerable of multivaluedattribute without a sub-attribute
// therefore, we default to evaluating the .Value member
var multiValuedAttributeType = property.PropertyType.GetGenericArguments()[0];
var multiValuedAttribute = Expression.Parameter(multiValuedAttributeType);
var valueAttribute = multiValuedAttributeType.GetProperty("Value", BindingFlags.Public | BindingFlags.Instance);
var valueExpression = Expression.TryCatch(
Expression.Block(Expression.Property(multiValuedAttribute, valueAttribute)),
Expression.Catch(
typeof(NullReferenceException),
Expression.Constant(valueAttribute.PropertyType.GetDefaultValue(), valueAttribute.PropertyType))
);
var valueLambda = Expression.Lambda(
CreateBinaryExpression(valueExpression, valueAttribute, operatorToken, valueToken),
multiValuedAttribute);
var anyMethod = MethodCache["any"].MakeGenericMethod(multiValuedAttributeType);
var anyPredicate = Expression.TryCatch(
Expression.Block(
Expression.Call(
anyMethod,
new List <Expression>
{
left,
valueLambda
})),
Expression.Catch(typeof(ArgumentNullException), Expression.Constant(false)));
return(Expression.Lambda(anyPredicate, argument));
}
return(Expression.Lambda <Func <TResource, bool> >(
CreateBinaryExpression(left, property, operatorToken, valueToken),
argument));
}