Angular directive to capitalize the first letter of an input field.

CapitalizeFirstLetter.js

angular.module('MyApp').directive("capitalizeFirstLetter",
    ['$',
        function ($) {
            return {
                restrict: 'A',
                require: 'ngModel',
                link: function (scope, element, attrs) {
                    var wasCapitalized = false;

                    function capitalizeFirstLetter() {
                        var currentValue = element.val();
                        if (!currentValue) {
                            return;
                        }

                        if (wasCapitalized) {
                            return;
                        }

                        if (currentValue.length === 1) {
                            var newValue = capitalize(currentValue);
                            wasCapitalized = true;

                            element.val(newValue);
                            scope.$apply();
                        }
                    }

                    function capitalize(item) {
                        return itemIsLowerCaseLetter(item) ? item.toUpperCase() : item;
                    }

                    function itemIsLowerCaseLetter(item) {
                        return item.toUpperCase().toLowerCase() === item;
                    }

                    element.bind('keypress', capitalizeFirstLetter);
                }
            };
        }
    ]
);