Searching for instances using getIntancesByFilter and ClientProcessService

Question

I am trying to get an array of all instances in a process so I can get some the data and use it to populate some dropdowns. I am using a custom, AJAX-enabled JSF presentation to call a server-side-no method in my component model. My code looks like this:
Fuego.Papi.Instance[] things;
Fuego.Papi.ClientProcessService cps = new Fuego.Papi.ClientProcessService();
cps.connect();
Fuego.Papi.InstanceFilter filter = new Fuego.Papi.InstanceFilter();
filter.create(cps);
filter.searchScope = SearchScope(ParticipantScope.ALL, StatusScope.ALL);
filter.addAttributeTo("projVar", Comparison.IS, "projValue");
things = cps.getInstancesByFilter(filter);
foreach (thing in things){
     logMessage("Thing - " + thing.activityName + ".", "INFO");
cps.disconnectFrom();
I think the code is failing at line filter.create(cps), but I can't be sure. When I launch the screenflow, I am presented with an error about invalid arguments for method signature [nameOfMethod]. I can't debug the method either because of this error.
If I remove everything south of cps.connect();, I can loop through the project vars defined in the process. I am using a ClientProcessService because I want to use the existing session from the workspace to get this data. Any thoughts?

Answer 1

I think you're just missing the processId in your logic ("/OrderEntry" in the logic below). Your use of "projValue" won't work unless you're looking for the hard coded string "projValue".
// Create objects used by the filter that searches the engine
ClientBusinessProcess cbp;
InstanceFilter instF;
// Connect to the process that is currently running.
// In this example, the process name is "Order Entry"
// (no space characters).
cbp.connectTo(processId : "/OrderEntry");
// create the filter
instF.create(processService : cbp.processService);
// filter based on instances done by ALL participants in any
//   activity between the Begin and End activities
//   (ONLY_INPROCESS)
instF.searchScope = SearchScope(participantScope : ParticipantScope.ALL, statusScope : StatusScope.ONLY_INPROCESS);
// Get the orders with a order status of "Rejected"
instF.addAttributeTo("projjVar", Comparison.IS, "Rejected");
. . .Dan
orderCount = length (getInstancesByFilter(cbp, instF))
return orderCount