angularjs – 如何限制角度JS中textarea中的单词

(function () {
    'use strict';
    var myAppModule = angular.module('myApp',[]);
    myAppModule.controller('MyController',function($scope) {
        $scope.textareaText = "";
    });

	myAppModule.directive('myMaxlength',['$compile','$log',function($compile,$log) {
		return {
			restrict: 'A',require: 'ngModel',link: function (scope,elem,attrs,ctrl) {
				attrs.$set("ngTrim","false");
                var maxlength = parseInt(attrs.myMaxlength,10);
                ctrl.$parsers.push(function (value) {
                    $log.info("In parser function value = [" + value + "].");
                    if (value.length > maxlength)
                    {
                        $log.info("The value [" + value + "] is too long!");
                        value = value.substr(0,maxlength);
                        ctrl.$setViewValue(value);
                        ctrl.$render();
                        $log.info("The value is now truncated as [" + value + "].");
                    }
                    return value;
                });
			}
		};
	}]);

    
})();

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div class="parent" ng-app="myApp">
    <h1>Textarea Maxlength = 5.</h1>
    <h3>Open the console to see debug info.</h3>
    <label for="text">Textarea label</label>:
    <textarea id="text" cols="40" rows="5" my-maxlength="5" ng-model="textareaText"></textarea>
    <br/><br/>
    <div>This option now works great because I'm using the $set method in the AngularJS attrs object to turn off ngTrim. Even adding spaces at the end of the string are truncated as expected.</div>
    <br/><br/>
    <div>Model Value=<span class="model">[{{textareaText}}]</span></div>
</div>