WP Json Ajax with data parse

Script: run only if field value not exist

get_loc = jQuery('#autcomplete-location').val();
    if(get_loc=='' && '<?php echo $_GET["action"]?>' == 'edit'){
        jQuery.ajax({
            url: '<?php echo admin_url('admin-ajax.php'); ?>',
            type: 'post',
            data: { 
             action: 'get_location_redis', 
             post_id: '<?php echo $_GET["post"]?>',
            },
            success: function(data) {
                obj = JSON.parse(data);
                full_loc = obj.storyLocation;
                full_city = obj.city_name;
                full_loc_len = full_loc.length;
                //console.log(full_loc+' '+full_loc_len);
                if(full_loc!='' && full_loc_len>=1){
                    for (var i=0; i<full_loc.length; i++) {
                        id_gen = (i>=1)?'-1':'';
                        jQuery('#autcomplete-location'+id_gen).val(full_loc[i]);
                    }
                }else if(full_city!='' && full_loc_len==1){
                    jQuery('#autcomplete-location').val(full_city);
                }
            },
            error: function() {
                console.log("Error");
       }
        });
    }

AJAX

add_action('wp_ajax_get_location_redis' , 'get_location_redis');
add_action('wp_ajax_nopriv_get_location_redis','get_location_redis');
function get_location_redis(){
    $post_id = $_REQUEST["post_id"];
     if(!empty($storyLocation) || !empty($city_name)){
        $storyLocation = $storyLocation;
        $city_name = $city_name;
    }else{
        $storyLocation = '';
        $city_name = '';
    }
     $loc_data = array("storyLocation"=>$storyLocation, "city_name"=>$city_name);
    echo json_encode($loc_data);
    die();
}