c# - Call .fail(error) without throwing exception -

using signalr, there possibility call .fail instead of .done when specific values returned hub method?

perhaps using signalr pipeline?

public bool delete(int addressid) {     // user should not able delete default address     if(addressservice.isdefaultaddressofcustomer(addressid))         return false; // should call .fail() on client      addressservice.delete(addressid);     return true; // should call .done() on client } 

the alternative throw exception avoid since error not server fault, user fault.

assuming convinced exception not right tool you, use custom attribute define mark methods false return value must translated error, , intercept incoming call buildincoming hubpipelinemodule:

http://msdn.microsoft.com/en-us/library/microsoft.aspnet.signalr.hubs.hubpipelinemodule.buildincoming(v=vs.118).aspx

from inside there can intercept call original method, inspect if it's marked attribute , if returned false, if it's case can throw exception there. bottom line is, still throw exception make call .fail() client-side, exception not bloat business logic. this:

public class failpipelinemodule : hubpipelinemodule {     public override func<ihubincominginvokercontext, task<object>> buildincoming(func<ihubincominginvokercontext, task<object>> invoke)     {         return base.buildincoming(context =>         {             var r = (bool)(invoke(context)).result;             if (context.methoddescriptor.attributes.any(a => typeof(failattribute) == a.gettype()) && !r)                 throw new applicationexception("false");             return task.fromresult((object)r);         });     } } 

you'll need define failattribute, use mark hub's method , register failpipelinemodule @ startup.