Attributes of type spell slot now store their slot level

app/imports/api/properties/Attributes.js

@@ -39,6 +39,11 @@ let AttributeSchema = new SimpleSchema({
     type: String,
     allowedValues: ['d4', 'd6', 'd8', 'd10', 'd12', 'd20'],
     optional: true,
+  },
+  // For type spellSlot, the level needs to be stored separately
+  spellSlotLevelCalculation: {
+    type: String,
+		optional: true,
   },
 	// The starting value, before effects
 	baseValueCalculation: {
@@ -81,6 +86,18 @@ let ComputedOnlyAttributeSchema = new SimpleSchema({
   },
   'baseValueErrors.$': {
     type: ErrorSchema,
+  },
+  // The result of spellSlotLevelCalculation
+  spellSlotLevelValue: {
+    type: SimpleSchema.oneOf(Number, String, Boolean),
+    optional: true,
+  },
+  spellSlotLevelErrors: {
+    type: Array,
+    optional: true,
+  },
+  'spellSlotLevelErrors.$': {
+    type: ErrorSchema,
   },
 	// The computed value of the attribute
   value: {