how to reference Header and Body properties of a message in a Routing rule?

Hi Stephen,

Interesting question.

The routing engine gets passed a context object that contains a Document object. This is the request object, so in your example you are directly accessing your Ens.AlertRequest with Document.AlertText.

I did a full dump of the context object so you can see what properties are available...

{
   "ActionTargets":"Foo.Productions.TEST2RoutingRule",
   "Adapter":"",
   "AlertGroups":"",
   "AlertOnBadMessage":null,
   "AlertOnError":false,
   "AlertRetryGracePeriod":0,
   "BadMessageHandler":"",
   "BusinessPartner":"",
   "BusinessRuleName":"Foo.Productions.TEST2RoutingRule",
   "Document":{
      "AlertDestination":"The alert destination",
      "AlertText":"The alert text",
      "AlertTime":"2018-10-29 15:29:18.517",
      "SessionId":null,
      "SourceConfigName":"souce"
   },
   "FailureTimeout":15,
   "ForceSyncSend":null,
   "InactivityTimeout":0,
   "MsgClass":"Ens.AlertRequest",
   "QueueCountAlert":0,
   "QueueWaitAlert":0,
   "ReplyCodeActions":"",
   "ResponseFrom":"",
   "ResponseTargetConfigNames":"",
   "ResponseTimeout":-1,
   "Retry":false,
   "RetryInterval":5,
   "Source":"EnsLib.Testing.Process",
   "SuspendMessage":false,
   "ThrottleDelay":0,
   "Validation":"",
   "aRespFrom":{

   }
}

There doesn't look to be any access to the Header object on the context object.

So I did a dump of the stack to see if its visible outside of the context object, but it looks like the routing rules are scoped off to just the arguments it takes...

{
   "Objects":{
      "pContext":{
         "Properties":{
            "ActionTargets":"Foo.Productions.TEST2RoutingRule",
            "Adapter":"",
            "AlertGroups":"",
            "AlertOnBadMessage":null,
            "AlertOnError":false,
            "AlertRetryGracePeriod":0,
            "BadMessageHandler":"",
            "BusinessPartner":"",
            "BusinessRuleName":"Foo.Productions.TEST2RoutingRule",
            "Document":{
               "AlertDestination":"3",
               "AlertText":"2",
               "AlertTime":"2018-10-29 15:36:24.273",
               "SessionId":null,
               "SourceConfigName":"1"
            },
            "FailureTimeout":15,
            "ForceSyncSend":null,
            "InactivityTimeout":0,
            "MsgClass":"Ens.AlertRequest",
            "QueueCountAlert":0,
            "QueueWaitAlert":0,
            "ReplyCodeActions":"",
            "ResponseFrom":"",
            "ResponseTargetConfigNames":"",
            "ResponseTimeout":-1,
            "Retry":false,
            "RetryInterval":5,
            "Source":"EnsLib.Testing.Process",
            "SuspendMessage":false,
            "ThrottleDelay":0,
            "Validation":"",
            "aRespFrom":{

            }
         },
         "Reference":"3@EnsLib.MsgRouter.RoutingEngine"
      }
   },
   "Primatives":{
      "pEffectiveBegin":"",
      "pEffectiveEnd":"",
      "pPassed":"1",
      "pReason":"",
      "pReturnValue":"",
      "pRuleSet":"",
      "tSC":"1"
   },
   "Stack":{
      "1":"zStart+62^Ens.Job.1 +2 : Set tInstance.%QuitTask=0, tSC=tInstance.OnTask()  Quit:('tSC)||tInstance.%QuitTask",
      "2":"zOnTask+42^Ens.Host.1 +1 : Set tSC=..MessageHeaderHandler(tRequestHeader,.tResponseHeader)",
      "3":"zMessageHeaderHandler+42^Ens.Actor.1 +1 : Set tSC=tBP.MessageHeaderHandler(pRequestHeader,.pResponseHeader,.tHandledError) ; Sets SessionId, we clear it",
      "4":"zMessageHeaderHandler+18^Ens.BusinessProcess.1 +1 : Set tSC=..OnRequest(..%request,.tResponse)",
      "5":"zOnRequest+21^EnsLib.MsgRouter.RoutingEngine.1 +1 : Quit ..doOneAction(request,\"rule:\"_tRuleName,,,.response) }",
      "6":"zdoOneAction+8^EnsLib.MsgRouter.RoutingEngine.1 +1 : Set tSC=##class(Ens.Rule.RuleDefinition).EvaluateRulesEx(tOneTarg, ..%SessionId, $this, $classname(), .tActionList) Quit:('tSC)",
      "7":"zEvaluateRulesEx+3^Ens.Rule.RuleDefinition.1 +1 : Quit ##class(Ens.Rule.Definition).EvaluateRules(pRuleName,pSessionId,pContext,pActivityName,.pReturnValue,.pReason)",
      "8":"zEvaluateRules+12^Ens.Rule.Definition.1 +1 : set tSC=$classmethod(tClassName,\"evaluateRuleDefinition\",pContext,.tRuleSet,.tEffectiveBegin,.tEffectiveEnd,.pReturnValue,.pReason)",
   }
}

So I think the short answer is going to be not directly.

I can access the request ID in the code behind, using the %Id() method, but the rule validator doesn't seem to like referencing it.

I had a quick hack and managed to find one way by using a custom function, its a hack but something like this, but maybe using dynamic SQL to access the value...

 Class Foo.FSET Extends Ens.Rule.FunctionSet
{

ClassMethod HeaderPropertyEquals(obj, name, value)
{
set bid=obj.%Id()
&sql(select id into :id from Ens.MessageHeader where MessageBodyId=:bid)
set mh=##class(Ens.MessageHeader).%OpenId(id)
quit $property(mh,name)=value
}

}

You can then call this function in the rule set as a condition...

HeaderPropertyEquals(Document,"SourceConfigName","Foo Service")

Can't say I have ever wanted to access the Header object, but interesting to hack around the code behind to see whats going on.

Sean