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https://issues.apache.org/activemq/browse/AMQNET-94?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jim Gomes resolved AMQNET-94.
-----------------------------
Resolution: Won't Fix
It is possible to change the {{IConnection}} interface to use the following
generic types to allow passing in a generic enumeration:
{code:borderStyle=solid}
interface IConnection
{
//...
ISession CreateSession(System.Enum acknowledgementMode);
System.Enum AcknowledgementMode { get; set; }
//...
}
{code}
However, I think that it will force more code to be written using explicit
casting in order to deal with the {{AcknowledgementMode}} property in the most
general cases.
Since using provider specific acknowledgment modes is the outlyer case, I think
using casting to show specific intent to deviate from standard modes is
preferred. The C# enum type system is robust enough to support the following
using the existing interface definition without reverting to generic
{{System.Enum}}:
{code:borderStyle=solid|title=Sample of Extant Flexibility}
public interface IConnection : IDisposable, IStartable, IStoppable
{
//...
ISession CreateSession(AcknowledgementMode acknowledgementMode);
AcknowledgementMode AcknowledgementMode { get; set; }
//...
}
enum MyAckModes
{
IgnoreDups,
Transactional,
Explicit
}
IConnection connection = GetConnection();
// Set the default ack mode
connection.AcknowledgementMode = (AcknowledgementMode) MyAckModes.IgnoreDups;
// Set session-specific ack mode
ISession session = connection.CreateSession((AcknowledgementMode)
MyAckModes.Explicit);
{code}
As can be seen from this snippet of code, the existing code base allows the use
of provider specific enumerations while providing type-safety and non-casting
for the general case. When a user of NMS wants to have low-level access to a
provider's unique acknowledgment modes, then they can do so and the C# enum
system will carry their values through, even if that acknowledgment mode value
is outside the range of the original {{AcknowledgmentMode}} enumeration. I
have created a sample C# app that demonstrates basic casting of enumerations to
show that provider specific enumeration values can be "carried" inside the
existing {{AcknowledgementMode}} enumeration. Since these values only make
sense to the individual providers, they will be the ones who will cast when
setting/getting the {{AcknowledgementMode}} property.
{code:borderStyle=solid|title=EnumTest.cs}
using System;
public class EnumTest
{
enum MyEnum { First, Second, Third }
enum ProviderEnum { Fourth, Fifth }
static void ShowEnum(System.Enum baseEnum)
{
Console.WriteLine("base = {0}", baseEnum);
ProviderEnum derived = (ProviderEnum) baseEnum;
Console.WriteLine("derived = {0}", derived);
}
static void Main()
{
ShowEnum(MyEnum.Second);
ShowEnum(MyEnum.Third);
}
}
{code}
When this sample application is run, the following is output:
{panel:title=EnumTest output|borderStyle=solid|bgColor=#FFFFCE}
base = Second
derived = Fifth
base = Third
derived = 2
{panel}
I hope that this addresses the concerns about using provider specific
extensions to the acknowledgment mode enumeration.
> Use of AcknowledgmentMode enum and boolean for priority limit use of NMS API
> for vendor extensions
> --------------------------------------------------------------------------------------------------
>
> Key: AMQNET-94
> URL: https://issues.apache.org/activemq/browse/AMQNET-94
> Project: ActiveMQ .Net
> Issue Type: Improvement
> Components: ActiveMQ Client
> Reporter: Mark Pollack
> Assignee: Jim Gomes
> Priority: Minor
> Fix For: 1.0
>
>
> This came up on the dev mailing list. The AcknowledgmentMode enumeration
> lists the standard JMS ack modes. However, vendors extend that, in
> particular TIBCO EMS. This should change to either an Enum, int, or string
> type so that the API will be more portable.
> The same issue exists in the IMessageProducer interface with the boolean
> value for persistent delivery instead of and int for "DeliveryMode". TIBCO
> EMS offers another value for delivery mode.
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