Defining my first REST API within InterSystems using iris-rest-Api-template as a basis and I am seeing if someone could provide me some guidance to see if I can make it work.  

In some of my other posts, I have been trying to come up with a way for our Enterprise Application Development team which works with .Net to build Applications to make a REST call to our instance of InterSystems to query some of the Cache Tables we have defined. 

Using the iris-rest-api-template, I have created the osuwmc.DataLookup.REST.Base.cls

Class osuwmc.DataLookup.REST.Base Extends %CSP.REST [ System = 3 ]
{

Parameter CHARSET = "utf-8";
Parameter CONTENTTYPE = "application/json";
Parameter HandleCorsRequest = 1;
Parameter PAGESIZE As INTEGER = 50;
ClassMethod OnPreDispatch(pUrl As %String, pMethod As %String, ByRef pContinue As %Boolean) As %Status
{
  SET tSC = $$$OK
  TRY {
    
    // Set the return type according to the Accept type in the request. Default is application/json.
    IF ('..AcceptsContentType(..#CONTENTTYPEJSON)) {
      SET tSC = ..ReportHttpStatusCode(..#HTTP406NOTACCEPTABLE), pContinue=0
      QUIT
        } ELSE {   
      // This always returns json
      SET %response.ContentType=..#CONTENTTYPEJSON
        }
        
        
        // read request object into %DynamicObject format
    IF ((pMethod'="POST") && (pMethod'="PUT")) || (%request.Content="") {
      SET %request.Content = {}
    } ELSE {
      IF '$isobject(%request.Content) {
        SET tContent = %request.Content
      } ELSE {
        SET tContent = ""
        WHILE '%request.Content.AtEnd {
          SET tContent = tContent_%request.Content.Read()
        }
      }
      IF (tContent="") {
        SET %request.Content = {}
      } ELSE {
        SET tContent = $zconvert(tContent, "I", "UTF8")
        SET %request.Content = ##class(%Library.DynamicObject).%FromJSON(tContent)
      }
    }
        
  } CATCH ex {
    SET tSC = ex.AsStatus()
  }
  QUIT ##class(%iKnow.REST.Base).%ErrorHandler(tSC, .pContinue)
}

ClassMethod %ProcessResult(pStatus As %Status = {$$$OK}, pResult As %DynamicObject = "") As %Status [ Internal ]
{
  #dim %response As %CSP.Response
  SET tSC = $$$OK
  IF $$$ISERR(pStatus) {
    SET %response.Status = 500
    SET tSC = ..StatusToJSON(pStatus, .tJSON)
    IF $isobject(tJSON) {
      SET pResult = tJSON
    } ELSE {
      SET pResult = { "errors": [ { "error": "Unknown error parsing status code" } ] }
    }
  } 
  ELSEIF pStatus=1 {
    IF '$isobject(pResult){
      SET pResult = {
      }
    }
  }
  ELSE {
    SET %response.Status = pStatus
    SET error = $PIECE(pStatus, " ", 2, *)
    SET pResult = {
      "error": (error)
    }
  }
  
  IF pResult.%Extends("%Library.DynamicAbstractObject") {
    WRITE pResult.%ToJSON()
  }
  ELSEIF pResult.%Extends("%JSON.Adaptor") {
    DO pResult.%JSONExport()
  }
  ELSEIF pResult.%Extends("%Stream.Object") {
    DO pResult.OutputToDevice()
  }
  
  QUIT tSC
}

ClassMethod ReportHttpStatusCode(pHttpStatus, pSC As %Status = {$$$OK}) As %Status
{
  Set %response.Status=pHttpStatus
  
  If $$$ISERR(pSC) Do ..outputStatus(pSC)
  /*
  If (+pHttpStatus>=400) {
    Set %response.ContentType = "application/json"
    SET pResult = {
      "error": ($PIECE(pHttpStatus, " ", 2, *))
    }
    Return ..%ProcessResult($$$OK, pResult)
  }*/
  Return $$$OK
}

}

and the osuwmc.DataLookup.REST.TableLookup

Class osuwmc.DataLookup.REST.TableLookup Extends osuwmc.DataLookup.REST.Base
{

Parameter Version = "1.0.0";
Parameter GlobalName = "^OSUWMCDataLookup.TableLookup";
XData UrlMap [ XMLNamespace = "http://www.intersystems.com/urlmap" ]
{
<Routes>  
    <!-- Server Info -->
    <Route Url="/" Method="GET" Call="GetInfo" Cors="true"/>
    <Route Url="/info" Method="GET" Call="GetAllEpicDepartments" Cors="true"/>
    </Routes>
}

ClassMethod GetInfo() As %Status
{
    SET version = ..#Version
    SET info = {
      "version": (version)
    }
    RETURN ..%ProcessResult($$$OK, info)
}

ClassMethod GetAllEpicDepartments() As %Status
{
    SET tSC = $$$OK
    set sql = "SELECT ID as DepartmentID, Abbr, Name, ExternalName, PhoneNumber, ApptPhone, FaxNumber, Address1, Address2, City, Zip, Specialty, RevLocID, RevLocName, BuildingCategoryID, BuildingName, DepCategoryTypeID, DepType, Center, EAFParent, CostCenter FROM osuwmc_Epic_Clarity.DepartmentMaster"
    do ##class(%ZEN.Auxiliary.jsonSQLProvider).%WriteJSONFromSQL(,sql)
    return tSC
}

ClassMethod GetEpicDepartment(ID As %String) As %Status
{
    SET tSC = $$$OK
    set sql = "SELECT ID as DepartmentID, Abbr, Name, ExternalName, PhoneNumber, ApptPhone, FaxNumber, Address1, Address2, City, Zip, Specialty, RevLocID, RevLocName, BuildingCategoryID, BuildingName, DepCategoryTypeID, DepType, Center, EAFParent, CostCenter FROM osuwmc_Epic_Clarity.DepartmentMaster WHERE ID = ?"
    do ##class(%ZEN.Auxiliary.jsonSQLProvider).%WriteJSONFromSQL(,,sql,ID)
    return tSC
}
ClassMethod SwaggerSpec() As %Status
{
  Set tSC = ##class(%REST.API).GetWebRESTApplication($NAMESPACE, %request.Application, .swagger)
  Do swagger.info.%Remove("x-ISC_Namespace")
  Set swagger.basePath = "/crud"
  Set swagger.info.title = "REST API to Access and Query OSUWMC Cache Tables"
  Set swagger.info.version = "0.1"
  Set swagger.host = "intengtest.osumc.edu"
  Return ..%ProcessResult($$$OK, swagger)
}

}

I defined the Web Application as /api/mgmnt/<namespace>/TableLookup with the osuwmc.DataLookup.REST.TableLookup as the Dispatch Class.

When I try to execute the REST call using POSTMAN, "msg": "ERROR #8754: Unable to use namespace: TABLELOOKUP."

If I try to use the sample class, I get a message saying that "The request URL was not found on the server" or a "404 Not Found"

I checked the Web Gateway to make sure the application was defined.

So, am I missing a step somewhere?