How to populate form dropdown with values depending on previous dropdown value?

[jezwn]

I've got this 3 dropdown fields, month, day and year. Upon selection of a specific month the day dropdown field should be populated with exactly the number of days for that particular month. Similiary it should be accountable for leap years as well. How to do that in AEM Forms?

[Mayank_Gandhi]

why don't you use Date Picker component?

[jezwn · Accepted solution]

In the code editor for day use the following logic,

function getDates(numberOfDays) {
var dates = [];
var toDates;
for (var i = 1; i <= numberOfDays; i++)
{
if (i < 10) {
toDates = "0" + i + "=0" + i;
dates.push(toDates);
} else {
toDates = i + "=" + i;
dates.push(toDates);
}
}
return dates;
}

if (birthMonth.value == "January" || birthMonth.value == "March" || birthMonth.value == "May" || birthMonth.value == "July" || birthMonth.value == "August" || birthMonth.value == "October" || birthMonth.value == "December") {

this.items = getDates(31);
} else if (birthMonth.value == "February") {
this.items = getDates(29);
} else {
this.items = getDates(30);
}