generate correct schema if discover return empty

demo/xmla_connection/wizard.js

@@ -138,13 +138,9 @@
         console.log(error);
       })
       .push(function (response) {
+        var arr = [],
+          row;
         if (response && response.numRows > 0) {
-          schema.properties.dimension = {
-            title: " ",
-            oneOf: []
-          };
-          var arr = schema.properties.dimension.oneOf,
-            row;
           while (response.hasMoreRows()) {
             row = response.readAsObject();
             if (row["DIMENSION_TYPE"] !== 2) {
@@ -158,6 +154,12 @@
             response.nextRow();
           }
         }
+        if (arr.length !== 0) {
+          schema.properties.dimension = {
+            title: " ",
+            oneOf: arr
+          };
+        }
       });
   }
 
@@ -167,13 +169,9 @@
         console.log(error);
       })
       .push(function (response) {
+        var arr = [],
+          row;
         if (response && response.numRows > 0) {
-          schema.properties.hierarchy = {
-            title: " ",
-            oneOf: []
-          };
-          var arr = schema.properties.hierarchy.oneOf,
-            row;
           while (response.hasMoreRows()) {
             row = response.readAsObject();
             arr.push({
@@ -183,6 +181,12 @@
             response.nextRow();
           }
         }
+        if (arr.length !== 0) {
+          schema.properties.hierarchy = {
+            title: " ",
+            oneOf: arr
+          };
+        }
       });
   }
 
@@ -192,13 +196,9 @@
         console.log(error);
       })
       .push(function (response) {
+        var arr = [],
+          row;
         if (response && response.numRows > 0) {
-          schema.properties.level = {
-            title: " ",
-            oneOf: []
-          };
-          var arr = schema.properties.level.oneOf,
-            row;
           while (response.hasMoreRows()) {
             row = response.readAsObject();
             arr.push({
@@ -208,6 +208,12 @@
             response.nextRow();
           }
         }
+        if (arr.length !== 0) {
+          schema.properties.level = {
+            title: " ",
+            oneOf: arr
+          };
+        }
       });
   }