dateFormat/altFormat accept week number and year (iso 8601)

I add to poorly hack the jquery datepicker plugin to get the week number (dateFormat) and the year (altFormat) from it.

The hack is bold and doesn't fit (i'm not js coder).

I did two functions that just c/p iso8601Week in formatDate:

getWeek (1to1 copy of iso8601Week) that return the week number

var getWeek = function(date) {
	var checkDate = new Date(date.getFullYear(), date.getMonth(), date.getDate());
	var firstMon = new Date(checkDate.getFullYear(), 1 - 1, 4); // First week always contains 4 Jan
	var firstDay = firstMon.getDay() || 7; // Day of week: Mon = 1, ..., Sun = 7
	firstMon.setDate(firstMon.getDate() + 1 - firstDay); // Preceding Monday
	if (firstDay < 4 && checkDate < firstMon) { // Adjust first three days in year if necessary
		checkDate.setDate(checkDate.getDate() - 3); // Generate for previous year
		return $.datepicker.iso8601Week(checkDate);
	} else if (checkDate > new Date(checkDate.getFullYear(), 12 - 1, 28)) { // Check last three days in year
		firstDay = new Date(checkDate.getFullYear() + 1, 1 - 1, 4).getDay() || 7;
		if (firstDay > 4 && (checkDate.getDay() || 7) < firstDay - 3) { // Adjust if necessary
			return 1;
		}
	}
	return Math.floor(((checkDate - firstMon) / 86400000) / 7) + 1; // Weeks to given date
};

and getWeekYear that return the correct year iso8601

		var getWeekYear = function(date) {
			var checkDate = new Date(date.getFullYear(), date.getMonth(), date.getDate());
			var firstMon = new Date(checkDate.getFullYear(), 1 - 1, 4); // First week always contains 4 Jan
			var firstDay = firstMon.getDay() || 7; // Day of week: Mon = 1, ..., Sun = 7
			firstMon.setDate(firstMon.getDate() + 1 - firstDay); // Preceding Monday
			if (firstDay < 4 && checkDate < firstMon) { // Adjust first three days in year if necessary
				checkDate.setDate(checkDate.getDate() - 3); // Generate for previous year
				return checkDate.getFullYear();
			} else if (checkDate > new Date(checkDate.getFullYear(), 12 - 1, 28)) { // Check last three days in year
				firstDay = new Date(checkDate.getFullYear() + 1, 1 - 1, 4).getDay() || 7;
				if (firstDay > 4 && (checkDate.getDay() || 7) < firstDay - 3) { // Adjust if necessary
					return checkDate.getFullYear() +1;
				}
			}
		return checkDate.getFullYear(); // Weeks to given date
		};

and another one that c/p formatNumber to get the zero fill on week number

		var fillMe = function(value, len) {
			var num = '' + value;
			while (num.length < len)
				num = '0' + num;
			return num;
		};

then I added two cases for the switch(format.charAt(iFormat))

						case 'w':
							output += getWeekYear(date);
							break;
						case 'W':
							output += fillMe( getWeek(date), 2 );
							break;

and here the call to the datepicker plugins

$("#week").datepicker({
	firstDay: 1,
	dateFormat: 'W',
	constrainInput: false, //hack did broke out this
	altField: '#year',
	altFormat: 'w'
	});

finally the html form

<input id="year" name="year" type="text" value="" />
<input id="week" name="week" type="text" value="" />

I had to do this fastly, it work for my need for now, but hoping that the dateFormat/altFormat could accept week number and year in iso8601 to be formatted.

the user stories :

user have to choose a year and a week to get in that week his data.

I can easily imagine row/<tr> highlight and the week number shown (little push on another request ;))

regards,

houba