GravityView Make (some) Search Fields Required (custom plugin)

gv-custom-required-search-fields.php

<?php
/*
Plugin Name: GravityView - Custom Required Search Fields
Plugin URI: https://gravityview.co/
Description: Custom Add-on to make certain GravityView Search fields required before performing the search
Author: Katz Web Services, Inc.
Version: 1.0.0
Author URI: http://www.katzwebservices.com

Copyright 2014 Katz Web Services, Inc.  (email: info@katzwebservices.com)

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

// tested with GravityView version 1.3

/** 
 * If you need to make some of the GravityView search fields required before search is submited
 *  - add as many lines as you need to define which fields are required
 *    e.g. -> 	jQuery('#search-box-filter_XYZ').prop('required', true );
 * 
 */
 
add_action('gravityview_after', 'gv_custom_make_search_fields_required' );
function gv_custom_make_search_fields_required() {
	?>
	<script>
		//define here the search fields that are required
		jQuery('#search-box-filter_2').prop('required', true );
		jQuery('#search-box-filter_1_3').prop('required', true );
		jQuery('#search-box-filter_1_6').prop('required', true );

		// validation magic
		jQuery('form.gv-widget-search').submit( function(e) {
			e.stopPropagation();
			var isValid = true;
			jQuery('.gv-widget-search input:required').each( function(){
				if( jQuery(this).val() === '' ) {
					isValid = false;
				}
			});
			return isValid;
		});
		
		// hide search results if search wasn't performed yet
		jQuery(document).ready(function() {
			if( jQuery('form.gv-widget-search').length > 0 ) {
				var gvSearchAction = jQuery('form.gv-widget-search').attr('action');
				if( gvSearchAction.indexOf('?') === -1 ) {
					jQuery('.gv-container').hide();
				} else {
					jQuery('.gv-container').show();
				}
			}
		});
	</script>
	<?php
}