/// <summary>Creates a custom method definition from it's label.</summary>
/// <param name="customMethodLabel">The label to call the custom method definition.</param>
/// <returns>The custom method created.</returns>
public static AggregationMethodDefinition Custom(string customMethodLabel)
{
ExceptionUtils.CheckArgumentNotNull(customMethodLabel, "customMethodLabel");
// Custom aggregation methods MUST use a namespace-qualified name (see [OData-ABNF]), i.e. contain at least one dot.
Debug.Assert(customMethodLabel.Contains(OData.ExpressionConstants.SymbolDot));
var aggregationMethod = new AggregationMethodDefinition(AggregationMethod.Custom);
aggregationMethod.MethodLabel = customMethodLabel;
return(aggregationMethod);
}
private IEdmTypeReference CreateAggregateExpressionTypeReference(SingleValueNode expression, AggregationMethodDefinition method)
{
var expressionType = expression.TypeReference;
if (expressionType == null && aggregateExpressionsCache != null)
{
var openProperty = expression as SingleValueOpenPropertyAccessNode;
if (openProperty != null)
{
expressionType = GetTypeReferenceByPropertyName(openProperty.Name);
}
}
switch (method.MethodKind)
{
case AggregationMethod.Average:
var expressionPrimitiveKind = expressionType.PrimitiveKind();
switch (expressionPrimitiveKind)
{
case EdmPrimitiveTypeKind.Int32:
case EdmPrimitiveTypeKind.Int64:
case EdmPrimitiveTypeKind.Double:
return(EdmCoreModel.Instance.GetPrimitive(EdmPrimitiveTypeKind.Double, expressionType.IsNullable));
case EdmPrimitiveTypeKind.Decimal:
return(EdmCoreModel.Instance.GetPrimitive(EdmPrimitiveTypeKind.Decimal, expressionType.IsNullable));
default:
throw new ODataException(
ODataErrorStrings.ApplyBinder_AggregateExpressionIncompatibleTypeForMethod(expression,
expressionPrimitiveKind));
}
case AggregationMethod.VirtualPropertyCount:
case AggregationMethod.CountDistinct:
// Issue #758: CountDistinct and $Count should return type Edm.Decimal with Scale="0" and sufficient Precision.
return(EdmCoreModel.Instance.GetPrimitive(EdmPrimitiveTypeKind.Int64, false));
case AggregationMethod.Max:
case AggregationMethod.Min:
case AggregationMethod.Sum:
return(expressionType);
default:
// Only the EdmModel knows which type the custom aggregation methods returns.
// Since we do not have a reference for it, right now we are assuming that all custom aggregation methods returns Doubles
// TODO: find a appropriate way of getting the return type.
return(EdmCoreModel.Instance.GetPrimitive(EdmPrimitiveTypeKind.Double, expressionType.IsNullable));
}
}
/// <summary>
/// Create a AggregateExpression.
/// </summary>
/// <param name="expression">The aggregation expression.</param>
/// <param name="methodDefinition">The <see cref="AggregationMethodDefinition"/>.</param>
/// <param name="alias">The aggregation alias.</param>
/// <param name="typeReference">The <see cref="IEdmTypeReference"/> of this aggregate expression.</param>
public AggregateExpression(SingleValueNode expression, AggregationMethodDefinition methodDefinition, string alias, IEdmTypeReference typeReference)
: this(expression, methodDefinition.MethodKind, alias, typeReference)
{
this.methodDefinition = methodDefinition;
}