Dont store empty classes or events if they are null upon change.

src/ignite-template.js

@@ -276,8 +276,13 @@ class IgniteTemplate {
             }
         }
 
+        //Remove the old value
         this.classes = this.classes.filter(cl => cl != oldValue && cl != newValue);
-        this.classes.push(newValue);
+
+        //Add the new value if its valid.
+        if (newValue !== null && newValue !== undefined) {
+            this.classes.push(newValue);
+        }
     }
 
     /**
@@ -353,7 +358,11 @@ class IgniteTemplate {
 
             //Remove the old value from the events
             this.events[eventName] = this.events[eventName].filter(ev => ev != oldValue);
-            this.events[eventName].push(newValue);
+
+            //Add the new value if it's needed
+            if (newValue !== null && newValue !== undefined) {
+                this.events[eventName].push(newValue);
+            }
         }
     }
 }