Moment.js - Date comparison: Catching min range

问题

My form has a Kendo DatePicker and a button that runs a JavaScript function prior to doing a form.submit(). I need to be able to compare my date that is entered against a lower limit, and prevent the code from going on (submitting the form) if it is earlier than my set date. I want to return false if the limit hasn't been breached, true if it has. I'll use this example to show what I'm trying to do in the validation code:

var lowerBound = new Date('1776', '6','4');  // July 4, 1776
var dateField = $('#myDateField').val();  // <-- comes from Kendo DatePicker
var dateToConsider = new Date(dateField);  // if this is 1/1/0001, this changes to 1/1/1901... not good, so I do this, instead....

var arrDate = dateField.split('/'); // I also check for '-', ' ', and '.'
dateToConsider = arrDate[2] + '-' + arrDate[0] + '-' arrDate[1]; // could add 'T00:00:00Z'; but don't think it matters

var momentDTC = moment(dateToConsider);
var lowerLimitBreached = moment(lowerBound).isAfter(momentDTC); // <-- this is always false

if (!lowerLimitBreached)
    $('form').submit();

I've been inputting 1/1/0001 into the control, and it keeps giving lowerLimitBreached as false, when it should be true, since 1-1-0001 is clearly earlier than 7-4-1776... I tried using .isBefore(), but met with the same issue, and the documentation actually says NOTE: moment().isBefore() has undefined behavior and should not be used!, so I dare not use that.

Moment documentation: http://momentjs.com/docs/#/query/

回答1:

Since you're using moment.js, don't use the JavaScript Date object at all. Stick to moment objects only.

//evaluates correctly
moment('0001-01-01');

//evaluates to Feb 2, 0001 - makes no sense...
new Date(Date.parse('0001-02-03'))
                            //^ but that's a 3, not a 2

//true - Jan 1, 0001 is before June 4, 1776
moment('0001-01-01').diff(moment('1776-06-04')) < 0

So, looking at your code, try this out:

var lowerBound = moment('1776-06-04');
var dateField = $('#myDateField').val();

// String replace and put in proper format for moment
dateField = dateField.replace(/(\/)/g,'-');
var year = dateField.split('-')[2];
var month = dateField.split('-')[0];
var day = dateField.split('-')[1];

if (month < 10) { month = "0" + month; }
if (day < 10) { day = "0" + day; }
dateField = year + '-' + month + '-' + day;

// Enter into moment and compare
var dateToConsider = moment(dateField);
var lowerLimitBreached = dateToConsider.diff(lowerBound) < 0;

if (lowerLimitBreached)
    $('form').submit();

回答2:

why don't you do this?

var lowerBound = moment('1776-6-4');
var dateField = moment($('#myDateField').val());
var lowerLimitBreached = moment(lowerBound).isAfter(dateField);

if (!lowerLimitBreached)
    $('form').submit();

You're already using moment, just convert the kendo picker's date to a moment object and use isAfter or isBefore.

If this doesn't work, please provide a date that the picker might return that's not working for you

来源：https://stackoverflow.com/questions/29245661/moment-js-date-comparison-catching-min-range