EDD-Filter-Downloads-By-Price.php

<?php
function sp_edd_filter_query($query, $atts)
{
    // We're going to modify the order and orderby parameters depending on variables contained in the URL
    if (isset($_GET['sp_orderby'])) {
        $orderby = $_GET['sp_orderby'];
        if(isset($orderby) && $orderby == 'free') {
            
            // Add meta query to filter downloads with price zero
            $meta_query = isset($query['meta_query']) ? $query['meta_query'] : array();
            // print_r($meta_query);
            $meta_query[] = array(
                'key'     => 'edd_price',
                'value'   => '0',
                'compare' => '='
            );
            $query['meta_query'] = $meta_query;

        } else if(isset($orderby) && $orderby == 'paid') {

            // Add meta query to filter downloads with price zero
            $meta_query = isset($query['meta_query']) ? $query['meta_query'] : array();
            // print_r($meta_query);
            $meta_query[] = array(
                'key'     => 'edd_price',
                'value'   => '0',
                'compare' => '!='
            );
            $query['meta_query'] = $meta_query;

        }
    }
    // Return the query, with thanks
    return $query;
}
add_filter('edd_downloads_query', 'sp_edd_filter_query', 10, 2);

function sp_edd_add_dropdown($display)
{
    $orderby = '';
    // Get the current parameter
    if (isset($_GET['sp_orderby'])) {
        $orderby = $_GET['sp_orderby'];
    }
    // Get the array of parameters
    $params = sp_edd_orderby_params();
    $select = '';
    if (!empty($params)) {
        // Build the select field
        $select = '<form class="sp-edd-sorting">';
        $select .= '<select class="sp-orderby" name="sp_orderby">';
        // Iterate through each parameter to add options to the select field
        foreach ($params as $param) {
            $select .= '<option value="' . $param['id'] . '" ' . selected($param['id'], $orderby, false) . '>' . $param['title'] . '</option>';
        }
        $select .= '</select>';
        $select .= '</form>';
        // Add a script to submit the form when a new selection is made
        $select .= '<script>
        jQuery(document).ready(function($) {
          $(".sp-orderby").change( function(){
            $(this).closest("form").submit();
          });
        });
      </script>';
        // Add the select field to the top of the downloads grid
        $display = $select . $display;
    }
    return $display;
}
add_filter('downloads_shortcode', 'sp_edd_add_dropdown', 10, 1);

function sp_edd_orderby_params()
{
    $params = array(
        'all' => array(
            'id' => 'all',
            'title' => __('All Extenssion', 'sp-for-edd'),
            'orderby' => 'edd_price', // Orderby parameter, must be legit WP_Query orderby param 
        ),
        'free' => array(
            'id' => 'free',
            'title' => __('Free Extenssion', 'sp-for-edd'),
            'orderby' => 'edd_price',
        ),
        'paid' => array(
            'id' => 'paid',
            'title' => __('Paid Extenssion', 'sp-for-edd'),
            'orderby' => 'edd_price',
        ),
    );
    $params = apply_filters('sp_edd_filter_orderby_params', $params);
    return $params;
}