Help with drop-down menus in form

timstring

I have a date field that is composed of drop-down menus for the month and day, and a number field for the year. Each one depends on the other. How can I do this? Here's the php code:

<?php

echo '<select name = "EndMonth">';

for ($counter = 1; $counter <= 12; $counter++)
	{
		if (strlen($counter) < 2) $counter = '0' . $counter;

		echo '<option value = ' . $counter . '>' . date('M', mktime(0, 0, 0, $counter, 1, ????)) . '</option>';  // Year should equal the year field that the user inputs
	}

echo '</select>';



echo '<select name = "EndDay">';

$EndMonth  = ??;   //should equal the month selected in the first drop-down menu


	$num = cal_days_in_month(CAL_GREGORIAN, $CountMonth, 2012);  //year should equal date that user inputs.
	for ($CountDay = 1; $CountDay <= $num; $CountDay++)
		{

			echo  $CountMonth . ', ' . $CountDay . ', ' . '&&<br>';
			if (strlen($CountDay) < 2) $CountDay = '0' . $CountDay;
			echo '<option value = ' . $CountDay . '>' . date('d', mktime(0, 0, 0, $EndMonth, $CountDay, ????)) . '</option>';  //same problem
		}

echo '</select>';

?>

I hate doing drop-down menus for a 4-digit year. Can I avoid this or am I stuck? Also, do I have to arrange my form by ISO date, or M-d-YYYY?

thanks
tim

bradgrafelman

timstring;11021383 wrote:
Each one depends on the other.

Not really; the only field that has a dependency on previous selections is the "Day" field. You don't need to supply a year to get the name of a given month, since the names of the months don't change from one calendar year to the next.

Furthermore, unless you're doing some sort of locale changing to match different languages, there's really no need to use date() and mktime() at all just to get the names of the months. In other words, you could just do something like:

$months = [1=>'Jan', 'Feb', 'Mar', /* etc. */];

foreach($months as $idx => $month)
    printf("<option value='%02d'>%s</option>\n", $idx, $month);

Likewise, I don't see why you're using date() and maketime() for the Day options either; you already know the ending day number for the month at that point, so when you're looping through all days from 1 until that ending day, why use mktime() and day() in order to get the exact same integer you started with? Seems rather silly.

As for the dependency part, though, you can't do it all once. PHP is executed on the server, the output is sent to the user, and the transaction is done. You'll need to generate a POST/GET request back to your server once the user has selected the year and month. To accomplish this, you could either have the user submit a form (which means they'll load a brand new page) or you could use AJAX (jQuery being the popular method) to submit the request behind-the-scenes and then populate the 'Day' dropdown accordingly.

However, note that if you're doing the Javascript approach, there's really no need to make a request back to your server at all - Javascript is perfectly capable of doing everything your PHP script above is doing without making any requests back to the server.

timstring

bradgrafelman;11021399 wrote:

$months = [1=>'Jan', 'Feb', 'Mar', /* etc. */];

foreach($months as $idx => $month)
    printf("<option value='%02d'>%s</option>\n", $idx, $month);

That eliminated several processes.

bradgrafelman;11021399 wrote:
Likewise, I don't see why you're using date() and maketime() for the Day options either; you already know the ending day number for the month at that point, so when you're looping through all days from 1 until that ending day, why use mktime() and day() in order to get the exact same integer you started with? Seems rather silly.

I'm just a silly guy. That also eliminated a few processor cycles.

bradgrafelman;11021399 wrote:
As for the dependency part, though, . . . you could use AJAX (jQuery being the popular method) to submit the request behind-the-scenes and then populate the 'Day' dropdown accordingly.

Another learning experience.

bradgrafelman;11021399 wrote:
However, note that if you're doing the Javascript approach, there's really no need to make a request back to your server at all - Javascript is perfectly capable of doing everything your PHP script above is doing without making any requests back to the server.

JavaScript ??!!! Egad, I'm just now wading into the depths of that vile language.

tanksalot for the hep
tim