Dynamic population of fields by 2 variables: current date and quantity field.

Okay, well I got one part working anyway - the date-based part. I just created two sets of fields - one for the regular price and one for the reduced price. Set classes for them ("full" and "reduced"). Since none of them are *required* all I had to do was write up a little function in my theme's functions.php file that checked the UNIX timestamp of today and compared them with the dates I want. If it's betweenJune 1 and August 15, it just hides the "full price" options, and displays only the reduced price stuff. On any other date, it'll show the full price and hide the reduced price.

So that works! Now I just need to figure out the thing with the "creating X number of input fileds where X = whatever number is in a previous field" thing.

Thanks!

Okay. Yeah, that won't work very well. What about having a "button" added so you can "add another field" on the fly, using jQuery (example: http://charlie.griefer.com/blog/jquery-dynamically-adding-form-elements/)? I see Gravity Forms doesn't do this now, but if I add a button with HTML input, will Gravity Forms pass the information?

Well I guess I know what I'm putting in as a "feature request" then :)

ETA: the suggestion above (creating fields and having them show using conditional logic based on what number is chosen in the dropdown) won't work, since I have variable conditions. The "how many" dropdown is shown only if a previous choice is made - so when I start adding the extra fields, the fields all show, because I can't do a conditional statement along the lines of "Show this field IF choice #1 is made AND when choice #2 is made OR choice #3 is made" So that won't fly.

I guess I'll keep digging!

Okay, I wanted to come back and update this, in case it would help anyone else. I edited the form to basically show/hide (and require) a field based on the date range. I'm gonna pop in a lot of code here, but hopefully it helps someone in the future. it uses the stuff I mentioned in the above post.

So you create one single form. let's say, for example, that you have a membership fee that changes based on the date. i.e. at the beginning of the year, it's full price, but when the year is half gone (say, in July) the price is reduced by 50% because the year's half over.

SO what I did was create a single form, and in it (for brevity's sake, we'll do one field, but there were several in my form) there's a "membership fee". Dropdown or quantity field, it doesn't matter. You just set it as "required", and set the CSS Class as "fullyear".

Duplicate the field. Change the price. Set the cssClass as "midyear".

Now, just add this function to your functions.php file:

// function to convert date to UNIX timestamp
function date_comparison_fun($date='') {
    if(!$date) $date = date('j F Y'); 			// default - today's date
	  $date = strtotime($date); 			// UNIX conversions
    return $date;
}

//Now use the above to change the form fields based on date
add_filter('gform_pre_render', 'change_form_stuff', 10, 2);
function change_form_stuff($form) {
  // dates MUST be entered in day Month Year format. Example: 20 September 2012
  // blank date is today's date.
  $today = date_comparison_fun();
  $year  = date('Y');                       // current year
  $start = date_comparison_fun('30 June ' . $year);
  $end   = date_comparison_fun('31 December ' . $year); 

  if($form['id'] == 1) {                      // form ID you want to use this in
    //start by changing the form title
    if( ($today > $start) && ($today < $end) )
      //if today is between start and end dates, it's Mid-Year stuff
      $form['title'] = $form['title'] . ' - Mid-Year Membership';

      //now get to the meat - the fields
      foreach($form['fields'] as &$field) {
        if( ($today > $start) && ($today < $end) ) { // if we're in between the dates
          if($field['cssClass'] == 'fullyear') {     //full year pricing is gone
            $field['isRequired'] = false;
            $field['cssClass'] = $field['cssClass'] . ' hide';
          }
        } else {                                    // else for the rest of the year
          if($field['cssClass'] == 'midyear') {     // mid-year pricing is gone
            $field['isRequired'] = false;
            $field['cssClass'] = $field['cssClass'] . ' hide';
          }
        } //end date check
      } // end foreach
    } //end checking which forms

  return $form;
}

What the above does is, if it's before July 1, it'll show the "full year" memebership; and set the "midyear" field as 1) not required and 2) add an additional class of "hide". if it's after July 1, but before December 31, it'll do the opposite - fullyear is now not required and hidden, and the midyear *is* required and shown.

the final step is to add this to your style.css file in your theme:

.hide {
display:none !important;
}

Hope that helps someone out :)