From 4a6d4de53ed1472c0cb2323292127495619d7ed9 Mon Sep 17 00:00:00 2001
From: Renat Yakubov <for@renat.biz>
Date: Mon, 24 Mar 2014 22:44:08 +0300
Subject: [PATCH] fix(filter.ngdoc): Check if "input" variable is defined

By default, "greeting" textfield in this example is prepopulated with "hello" text, but it's pretty easy to copy just filter code to use it in your app. If your textfield is empty while app loads, you'll get an error: "Error: [$interpolate:interr] Can't interpolate: Reverse: {{greeting|reverse}} TypeError: Cannot read property 'length' of undefined". To prevent this, we should check "input" variable, and proceed only in case it is defined.

Closes #6819.
---
 docs/content/guide/filter.ngdoc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/content/guide/filter.ngdoc b/docs/content/guide/filter.ngdoc
index 8eedf14c81df..9ef8bcc0f99b 100644
--- a/docs/content/guide/filter.ngdoc
+++ b/docs/content/guide/filter.ngdoc
@@ -103,6 +103,7 @@ text upper-case.
     angular.module('MyReverseModule', []).
       filter('reverse', function() {
         return function(input, uppercase) {
+          input = input || '';
           var out = "";
           for (var i = 0; i < input.length; i++) {
             out = input.charAt(i) + out;