angularjs: allows only numbers to be typed into a text box

This code shows the example how to prevent entering non digit symbols.

angular.module('app').
  directive('onlyDigits', function () {

    return {
        restrict: 'A',
        require: '?ngModel',
        link: function (scope, element, attrs, modelCtrl) {
            modelCtrl.$parsers.push(function (inputValue) {
                if (inputValue == undefined) return '';
                var transformedInput = inputValue.replace(/[^0-9]/g, '');
                if (transformedInput !== inputValue) {
                    modelCtrl.$setViewValue(transformedInput);
                    modelCtrl.$render();
                }
                return transformedInput;
            });
        }
    };
});

HTML

 <input type="text" name="number" only-digits>

// Just type 123

  .directive('onlyDigits', function () {
    return {
      require: 'ngModel',
      restrict: 'A',
      link: function (scope, element, attr, ctrl) {
        function inputValue(val) {
          if (val) {
            var digits = val.replace(/[^0-9]/g, '');

            if (digits !== val) {
              ctrl.$setViewValue(digits);
              ctrl.$render();
            }
            return parseInt(digits,10);
          }
          return undefined;
        }            
        ctrl.$parsers.push(inputValue);
      }
    };
});

// type: 123 or 123.45

 .directive('onlyDigits', function () {
    return {
      require: 'ngModel',
      restrict: 'A',
      link: function (scope, element, attr, ctrl) {
        function inputValue(val) {
          if (val) {
            var digits = val.replace(/[^0-9.]/g, '');

            if (digits.split('.').length > 2) {
              digits = digits.substring(0, digits.length - 1);
            }

            if (digits !== val) {
              ctrl.$setViewValue(digits);
              ctrl.$render();
            }
            return parseFloat(digits);
          }
          return undefined;
        }            
        ctrl.$parsers.push(inputValue);
      }
    };
 });

I just used ng-keypress in the directive for my input.

HTML:

<input type="text" ng-keypress="filterValue($event)"/>

JS:

$scope.filterValue = function($event){
        if(isNaN(String.fromCharCode($event.keyCode))){
            $event.preventDefault();
        }
};

This functionality just what you need. http://docs.angularjs.org/api/ng.directive:input.number

EDIT:

You can wrap the jquery plugin into directive. I created an example here: http://jsfiddle.net/anazimok/jTJCF/

HTML:

<div ng-app="myApp">
    <div>
        <input type="text" min="0" max="99" number-mask="" ng-model="message">
            <button ng-click="handleClick()">Broadcast</button>
    </div>

</div>

CSS:

.ng-invalid {
    border: 1px solid red;
}

JS:

// declare a module
var app = angular.module('myApp', []);

app.directive('numberMask', function() {
    return {
        restrict: 'A',
        link: function(scope, element, attrs) {
            $(element).numeric();
        }
    }
});