input type checking (datetime, email, etc)

example.js

jQuery(function ($) {
    if (!inputsupport('datetime-local')) {
        $('[type=datetime-local]').each(function () {
            var $input = $(this), placeholder = $input.attr('placeholder');
            $input.attr({
                type: 'text',
                placeholder: this.hasAttribute('placeholder') ? placeholder + ' (JJJJ-MM-DD UU:MM)' : 'JJJJ-MM-DD UU:MM',
                pattern: '20\\d{2}(-|\/)((0[1-9])|(1[0-2]))(-|\/)((0[1-9])|([1-2][0-9])|(3[0-1]))(T|\\s)(([0-1][0-9])|(2[0-3])):([0-5][0-9])(:([0-5][0-9]))?'
            });
        });
    }
});

inputsupport.js

var inputsupport = (function () {
    // private variables.
    var support = {}, input;

    // the actual check.
    return function (type) {
        if (!support.hasOwnProperty(type)) {
            input = input || document.createElement('input');
            input.type = type;
            // input.type is set back to text if not supported,
            // so we can just compare the type parameter with the input type property/attribute.
            support[type] = input.type == type;
        }
        return support[type];
    }
})();