.net - Is there a standard way to use attributes to modify how WCF operations behave? -

.net - Is there a standard way to use attributes to modify how WCF operations behave? -

i'm working on funky code right now, , i've been wondering whether or not can utilize attributes modify how wcf operation behaves, maybe create perform additional checking or create skip logic.

for example, if had next request envelope:

[messagecontract] public class userrequest { [messagebodymember] public string sessionkey { get; set; } [messagebodymember] public usermodel user { get; set; } }

and next service operations:

[forcesession] void adduser ( userrequest request ) { } void edituser ( userrequest request ) { }

we have automatic functionality on adduser operation checks request's session key exists in current httpcontext. maybe equivalent of checking httpcontext.current.session[request.sessionkey] != null, end either rejects phone call (sends empty response envelope) or processes it.

of course, add together checking code @ start of each operation matter, can pretty repetitive pretty fast, if i'm working lot of operations.

how should go implementing of sort?

wcf services utilize attributes natively check classes like:

servicecontractattribute, operationcontractattribute messagecontractattriubte, messageheaderattriubte, messagebodymemberattribute webgetattribute, webinvokeattribute servicebehaviorattribute, operationbehaviorattribute, callbackbehaviorattriubte serviceknowntypeattribute, faultcontractattriubte datacontractformatattribute, xmlserializerformatattribute transactionflowattribute, deliveryrequirementsattribute aspnetcompatibilityrequirementsattribute and several others

these attributes impact wcf processing wcf offers big extensibility model several injection points can add together own processing implementing of these interfaces in custom attribute:

iservicebehavior - affects whole service iendpointbehavior - affects single endpoint ioperationbehavior - affects single operation icontractbehavior - affects single service or info contract

these behaviors can contain logic or add together other more advanced custom features like:

iparameterinspector - illustration custom parameter validation operation idispatchmessageformater - dealing serialization , deserialization on server side iclientmessageformater - dealing serialization , deserialization on client side idispatchmessageinspector - message modification or validation on server side iclientmessageinspector - message modification or validation on client side idispatchoperationselector - selection of operation handling incoming message on server side iclientoperationselector - based on proxy method called can select different operation called client side ioperationinvoker - invoking operation - allows working operation parameters , illustration add together other parameters not passed in message stored locally ierrorhandler - global error handling iinstancecontextprovider - custom instance context handling - basis if want implement custom session handling in wcf iinstanceprovider - custom service instance lifetime handling any many others

as can see extensibility of wcf pretty big - imho asp.net mvc best in whole .net framework (at to the lowest degree among parts i'm regularly using). custom behaviors 1 part of wcf extensibility. sec part deals custom bindings , channels.

if want know more wcf extensibility check

wcf extensibility samples carlos figueira's blog first-class articles extensibility

but need? first check existing attributes if offer functionality looking for. next think session - asp.net session not provided wcf service. must turn on aspnetcompatibility , after degrade wcf service asmx service. after can have problems asp.net session because info session transferred in cookie , wcf default doesn't utilize them.

for lastly if need custom attributes add together logic selected methods more looks scenario aop (aspect oriented programming) can offered outside of wcf through several ioc (inversion of control) containers ms unity, windsor castle or spring.net. alternative pure aop framework - postsharp.

for aop unity can check several articles dino esposito msdn magazine:

aspect-oriented programming, interception , unity 2.0 interceptors in unity policy injection in unity

for spring.net check excellent documentation. didn't utilize aop windsor find plenty of articles on internet. postsharp mentioned tool commercial. has free version smaller feature set can find features need in commercial version.

.net wcf attributes