If you are still using WCF you might have stumbled upon this problem: WCF allows you to throw certain Faults in your operation, but unfortunatly it is a bit awkward to configure if you want “Global Fault Contracts”. With this solution here it should be pretty easy to get “Global Faults”:
Define the Fault on the Server Side:
Let’s say we want to throw the following fault in all our operations:
[DataContract]
public class FoobarFault
{
}
Register the Fault
The tricky part in WCF is to “configure” WCF that it will populate the fault. You can do this manually via the [FaultContract-Attribute] on each operation, but if you are looking for a global WCF fault configuration, you need to apply it as a contract behavior like this:
[AttributeUsage(AttributeTargets.Interface, AllowMultiple = false, Inherited = true)]
public class GlobalFaultsAttribute : Attribute, IContractBehavior
{
// this is a list of our global fault detail classes.
static Type[] Faults = new Type[]
{
typeof(FoobarFault),
};
public void AddBindingParameters(
ContractDescription contractDescription,
ServiceEndpoint endpoint,
BindingParameterCollection bindingParameters)
{
}
public void ApplyClientBehavior(
ContractDescription contractDescription,
ServiceEndpoint endpoint,
ClientRuntime clientRuntime)
{
}
public void ApplyDispatchBehavior(
ContractDescription contractDescription,
ServiceEndpoint endpoint,
DispatchRuntime dispatchRuntime)
{
}
public void Validate(
ContractDescription contractDescription,
ServiceEndpoint endpoint)
{
foreach (OperationDescription op in contractDescription.Operations)
{
foreach (Type fault in Faults)
{
op.Faults.Add(MakeFault(fault));
}
}
}
private FaultDescription MakeFault(Type detailType)
{
string action = detailType.Name;
DescriptionAttribute description = (DescriptionAttribute)
Attribute.GetCustomAttribute(detailType, typeof(DescriptionAttribute));
if (description != null)
action = description.Description;
FaultDescription fd = new FaultDescription(action);
fd.DetailType = detailType;
fd.Name = detailType.Name;
return fd;
}
}
Now we can apply this ContractBehavior in the Service just like this:
[ServiceBehavior(...), GlobalFaults]
public class FoobarService
...
To use our Fault, just throw it as a FaultException:
throw new FaultException<FoobarFault>(new FoobarFault(), "Foobar happend!");
Client Side
On the client side you should now be able to catch this exception just like this:
try
{
...
}
catch (Exception ex)
{
if (ex is FaultException faultException)
{
if (faultException.Action == nameof(FoobarFault))
{
...
}
}
}
Hope this helps!
(This old topic was still on my “To-blog” list, even if WCF is quite old, maybe someone is looking for something like this)
Further Links:
- WCF: Contract-level FaultContract The code above was more or less adopted from his great blogpost!
