I have a simple page that shows the hash of a string as someone types it into the page. I found that the page had a JavaScript error
Error: [$rootScope:infdig] http://errors.angularjs.org/1.2.26/$rootScope/infdig?p0=10&p1=%5B%5B%22sha1…75651%2C1080464653%2C-772792499%5D%2C%5C%22sigBytes%5C%22%3A20%7D%22%5D%5D
A very simplified version of the page is
<html lang="en">
<head>
<script src="http://crypto-js.googlecode.com/svn/tags/3.1.2/build/rollups/sha1.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.26/angular.min.js"></script>
<script>
function MyCtrl($scope) {
$scope.sha1 = function(pwd) {
return CryptoJS.SHA1(pwd);
};
}
</script>
</head>
<body>
<div class="app" ng-app ng-controller="MyCtrl">
<span ng-bind="sha1('bar')"></span>
</div>
</body>
</html>
which is available as Plunker http://plnkr.co/edit/vmBtH8B2EKsdcfZVGlMH.
What I am trying to do in the original page is recalculate the hash as someone types into the form field, and the input field definition looked like this
<input id="password" ng-model="password" type="text" placeholder="Password">
and the ng-bind is really ng-bind="sha1(password)", but the simple static case in the Plunker exhibits the same behavior.
I gather that the infdig error has to do with too many $digest cycles, but I don't see how that would happen here. It looks like the hash computation triggers the error, because returning a static string from the sha1 function causes no error.
Providing ng-bind="sha1('bar')" makes the digest cycle unstable, everytime sha1 function returns a different object (reference is different) and your digest cycle has to run again to stabilize it and every digest cycle again evaluates the ng-bind function expression and it goes on till it reaches the max limit set (10). You can also easily replicate this issue by just doing return [] in your scope method. This is just a side effect of not so good practice of binding a function expression to ng-bind as it runs every digest cycle, if at all used it should be carefully evaluated.
One simple solution is to bind ng-change/ng-blur event on your password or any other trigger and just bind ng-bind to a property instead of a function expression.
angular.module('app',[])
.constant('Crypto', window.CryptoJS);
function MyCtrl($scope, Crypto) {
$scope.encrypt = function() {
$scope.encrypted = Crypto.SHA1($scope.password);
};
}<html lang="en" ng-app="app">
<head>
<script src="http://crypto-js.googlecode.com/svn/tags/3.1.2/build/rollups/sha1.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.26/angular.min.js"></script>
</head>
<body>
<div class="app" ng-app ng-controller="MyCtrl">
<input id="password" ng-model="password" type="password" placeholder="Password" ng-change="encrypt()">
<span ng-bind="encrypted"></span>
</div>
</body>
</html>For better usage of DI i have placed crpto in a constant and inject it where needed.