/// <summary>
/// Validate the arguments to either isof or cast
/// </summary>
/// <param name="state">the current state of the binding algorithm</param>
/// <param name="isCast">flag to indicate which function we're validating</param>
/// <param name="args">the list of arguments, which could be changed</param>
/// <returns>the return type of the function.</returns>
private static IEdmTypeReference ValidateIsOfOrCast(BindingState state, bool isCast, ref List <QueryNode> args)
{
if (args.Count != 1 && args.Count != 2)
{
throw new ODataErrorException(
ODataErrorStrings.MetadataBinder_CastOrIsOfExpressionWithWrongNumberOfOperands(args.Count));
}
ConstantNode typeArgument = args.Last() as ConstantNode;
IEdmTypeReference returnType = null;
if (typeArgument != null)
{
returnType = TryGetTypeReference(state.Model, typeArgument.Value as string, state.Configuration.Resolver);
}
if (returnType == null)
{
throw new ODataException(ODataErrorStrings.MetadataBinder_CastOrIsOfFunctionWithoutATypeArgument);
}
if (returnType.IsCollection())
{
throw new ODataException(ODataErrorStrings.MetadataBinder_CastOrIsOfCollectionsNotSupported);
}
// if we only have one argument, then add the implicit range variable as the first argument.
if (args.Count == 1)
{
args = new List <QueryNode>()
{
new EntityRangeVariableReferenceNode(
state.ImplicitRangeVariable.Name,
state.ImplicitRangeVariable as EntityRangeVariable),
args[0]
};
}
else if (!(args[0] is SingleValueNode))
{
throw new ODataException(ODataErrorStrings.MetadataBinder_CastOrIsOfCollectionsNotSupported);
}
if (isCast && (args.Count == 2))
{
// throw if cast enum to not-string :
if ((args[0].GetEdmTypeReference() is IEdmEnumTypeReference) &&
!string.Equals(typeArgument.Value as string, Microsoft.OData.Core.Metadata.EdmConstants.EdmStringTypeName, StringComparison.Ordinal))
{
throw new ODataException(ODataErrorStrings.CastBinder_EnumOnlyCastToOrFromString);
}
// throw if cast not-string to enum :
while (returnType is IEdmEnumTypeReference)
{
IEdmTypeReference edmTypeReference = args[0].GetEdmTypeReference();
if (edmTypeReference == null)
{
// Support cast null to enum
break;
}
IEdmPrimitiveTypeReference referenceTmp = edmTypeReference as IEdmPrimitiveTypeReference;
if (referenceTmp != null)
{
IEdmPrimitiveType typeTmp = referenceTmp.Definition as IEdmPrimitiveType;
if ((typeTmp != null) && (typeTmp.PrimitiveKind == EdmPrimitiveTypeKind.String))
{
break;
}
}
throw new ODataException(ODataErrorStrings.CastBinder_EnumOnlyCastToOrFromString);
}
}
if (isCast)
{
return(returnType);
}
else
{
return(EdmCoreModel.Instance.GetBoolean(true));
}
}
