Add -1 for value on query all steps.

api/server/api_types.py

@@ -245,10 +245,10 @@ class ViewInfo(DataVarsSerializer):
             varGroups = datavars.getGroups()
             lastGroup = len(varGroups)-1
             # interate all vars group
-            if step in(0,None) or allsteps:
+            if step in(0,-1,None) or allsteps:
                 self.groups.append(self.stepGroup(varGroups,brief))
             for i, groupInfo in enumerate(varGroups):
-                if step is None or step == i:
+                if step in (None,-1) or step == i:
                     self.groups.append(GroupField(dv=datavars,info=groupInfo,
                                          last=(lastGroup==i),expert=expert))
         else: