Why is using $parse deprecated in angularjs?

Question

JavaScript

Friends, there is such a directive (brazenly taken from github):

(function() {
  "use strict";

  angular.module('app.common').directive('match', passwordVerify);

  function passwordVerify ($parse) {
    return {
      require: '?ngModel',
      restrict: 'A',
      link: function(scope, elem, attrs, ctrl) {


        var matchGetter = $parse(attrs.match);
        var caselessGetter = $parse(attrs.matchCaseless);
        var noMatchGetter = $parse(attrs.notMatch);

        scope.$watch(getMatchValue, function(){
          ctrl.$$parseAndValidate();
        });

        ctrl.$validators.match = function(){
          var match = getMatchValue();
          var notMatch = noMatchGetter(scope);
          var value;

          if(caselessGetter(scope)){
            value = angular.lowercase(ctrl.$viewValue) === angular.lowercase(match);
          }else{
            value = ctrl.$viewValue === match;
          }
          value ^= notMatch;
          return !!value;
        };

        function getMatchValue(){
          var match = matchGetter(scope);
          if(angular.isObject(match) && match.hasOwnProperty('$viewValue')){
            match = match.$viewValue;
          }
          return match;
        }
      }
    };
  }

})();

But I was turned into a pull request with the justification that $parse == eval. But 99% of directives use parse when it is necessary to compare 2 fields.

Answer 1

Using $parse inside a link directive is normal practice, but you need to understand why you're doing it.
In your example, it is enough to replace parse with property binding in the scope. The only reason $parse is used here is a micro-optimization to reduce the number of watchers.
updated
Correction, the only reason why $parse is used here instead of an isolated scope is that ngModel already has an isolated scope and Angular will simply not allow two directives with isolated scopes to be created on the same element.

Answer 2

$parse != eval, a more or less isolated function is formed there, and eval is not terrible if you only run your own code.
"Half" Angular.js is based on $parse

Answer 3

Maybe because it is almost the same as eval? Therefore, you need to carefully check the input parameters. And you immediately call it from attribute values, without even checking them for anything. Well, tracking down errors in such things is extremely difficult.
habrahabr.ru/post/244001/#comments