diff --git a/superset/assets/javascripts/modules/sandbox.js b/superset/assets/javascripts/modules/sandbox.js
index 3439c0319f9f6..a139013d592b0 100644
--- a/superset/assets/javascripts/modules/sandbox.js
+++ b/superset/assets/javascripts/modules/sandbox.js
@@ -22,6 +22,10 @@ export default function sandboxedEval(code, context, opts) {
   Object.keys(sandboxContext).forEach(function (key) {
     sandbox[key] = sandboxContext[key];
   });
-  vm.runInNewContext(codeToEval, sandbox, opts);
-  return sandbox[resultKey];
+  try {
+    vm.runInNewContext(codeToEval, sandbox, opts);
+    return sandbox[resultKey];
+  } catch (error) {
+    return () => error;
+  }
 }
diff --git a/superset/viz.py b/superset/viz.py
index 0c552623258ea..ebcbac4a93e33 100644
--- a/superset/viz.py
+++ b/superset/viz.py
@@ -2037,6 +2037,7 @@ def get_metrics(self):
 
     def get_properties(self, d):
         return {
+            'metric': d.get(self.metric),
             'radius': self.fixed_value if self.fixed_value else d.get(self.metric),
             'cat_color': d.get(self.dim) if self.dim else None,
             'position': d.get('spatial'),