Improve bindings between components.

src/operations/operations.html

@@ -18,9 +18,7 @@
 <div>
   <div class="row">
     <div class="col-md-9">
-      <balance-chart
-        min-date="operationsCtrl.minDate"
-        max-date="operationsCtrl.maxDate"/>
+      <balance-chart on-update="operationsCtrl.onUpdate(minDate, maxDate)"/>
     </div>
     <div class="col-md-3"></div>
   </div>