From 2e1f780cf9fb70aef2e8fcb2e4c8fd74b01c4d97 Mon Sep 17 00:00:00 2001
From: Grzegorz Bera <gberus@gmail.com>
Date: Fri, 10 Apr 2015 10:39:31 +0200
Subject: [PATCH] small optimization

---
 src/handsontable.formula.js | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/handsontable.formula.js b/src/handsontable.formula.js
index 2c0cd1d..7201d0e 100644
--- a/src/handsontable.formula.js
+++ b/src/handsontable.formula.js
@@ -3,8 +3,18 @@
 
   function HandsontableFormula() {
 
+    var isFormula = function (value) {
+      if (value) {
+        if (value[0] === '=') {
+          return true;
+        }
+      }
+
+      return false;
+    };
+
     var formulaRenderer = function (instance, TD, row, col, prop, value, cellProperties) {
-      if (instance.formulasEnabled) {
+      if (instance.formulasEnabled && isFormula(value)) {
         // translate coordinates into cellId
         var cellId = instance.plugin.utils.translateCellCoords({row: row, col: col}),
           prevFormula = null,
@@ -57,6 +67,7 @@
             // parse formula
             var newValue = instance.plugin.parse(formula, {row: row, col: col, id: cellId});
 
+            // check if update needed
             needUpdate = (newValue.error === '#NEED_UPDATE');
 
             // update item value and error