app .service('textTransformService', function () {
        return {
            transform: function (element, ngModelController, callBack) {
                element.on('input', function () {
 
                    var currentViewValue = ngModelController.$viewValue;
                    var modifiedViewValue = callBack(currentViewValue);
 
                    var start = this.selectionStart;
                    var end = this.selectionEnd + modifiedViewValue.length - currentViewValue.length;
 
                    ngModelController.$setViewValue(modifiedViewValue);
                    ngModelController.$render();
                    this.setSelectionRange(start, end);
                });
            }
        };
    })
    .directive('textTransformUppercase', ['textTransformService', function (srvc) {
        return {
            restrict: 'A',
            require: '?ngModel',
            link: function (scope, element, attrs, ngModelController) {
                srvc.transform(element, ngModelController, angular.uppercase);
            }
        };
    }]).directive('textTransformLowercase', ['textTransformService', function (srvc) {
        return {
            restrict: 'A',
            require: '?ngModel',
            link: function (scope, element, attrs, ngModelController) {
                srvc.transform(element, ngModelController, angular.lowercase);
            }
        };
    }]).directive('textTransformCapitalize', ['textTransformService', function (srvc) {
        return {
            restrict: 'A',
            require: '?ngModel',
            link: function (scope, element, attrs, ngModelController) {
                function capitalizeCallback(currentViewValue) {
                    function capitalize(txt) {
                        return angular.uppercase(txt.charAt(0)) + txt.substr(1);
                    }
                    return currentViewValue.replace(/\w\S*/g, capitalize);
                }
                srvc.transform(element, ngModelController, capitalizeCallback);
            }
        };
    }]);