New DeepSeeREST for MDX->JSON execution.

Author: eduard93

MDX2JSON/REST.cls.xml

@@ -248,7 +248,13 @@ Converts incoming request object and calls abovementioned method.]]></Descriptio
 <ReturnType>%Status</ReturnType>
 <Implementation><![CDATA[
     try {
-        set st = ##class(MDX2JSON.Utils).WriteJSONfromMDX($$$R("MDX"))
+	    if $$$R("Engine")="DeepSeeREST" {
+		    // DeepSeeREST engine for MDX->JSON transformation. Only in 15.3+
+		    set st = ##class(MDX2JSON.Utils).WriteJSONfromMDXNew($$$R("MDX"))
+	    } else {
+		    // Default MDX2JSON engine. 14.1+
+        	set st = ##class(MDX2JSON.Utils).WriteJSONfromMDX($$$R("MDX"))
+	    }
     } catch ex {
         set st=ex.AsStatus()
     }

MDX2JSON/Utils.cls.xml

@@ -70,9 +70,13 @@ Automatic processing of MDX query and outputting resulting JSON.<br>
 <FormalSpec>pMDX:%String</FormalSpec>
 <ReturnType>%Status</ReturnType>
 <Implementation><![CDATA[
-	set Provider = ##class(%ZEN.Auxiliary.jsonMDXProvider).%New()
-	set Provider.mdxQuery = pMDX
-	set st = tProvider.%DrawJSON()
+	#if $$$comClassDefined("%ZEN.Auxiliary.jsonMDXProvider")
+		set Provider = ##class(%ZEN.Auxiliary.jsonMDXProvider).%New()
+		set Provider.mdxQuery = pMDX
+		set st = tProvider.%DrawJSON()
+	#else
+		set st = $$$ERROR($$$GeneralError,"Class %ZEN.Auxiliary.jsonMDXProvider does not exist")
+	#endif
 	return st
 ]]></Implementation>
 </Method>