如何用插件的自定义版本替换插件中的函数。

插件的原始功能是：

function sep_get_the_event_end_date($post = NULL) {
    $post = get_post($post);
    if ($post->post_type !== \'event_listing\') {
        return;
    }
    $event_xml = get_post_meta(get_the_ID(), \'event_meta\', TRUE);
    $xml_object = new SimpleXMLElement($event_xml);
    $end_date = isset($xml_object->end_date) ? $xml_object->end_date : \'\';
    $event_date = isset($xml_object->event_date) ? $xml_object->event_date : \'\';
    if (isset($end_date) and \'\'  $end_date and \'checked\'  $event_date) {
        $end_date = isset($xml_object->end_date) ? $xml_object->end_date : \'\';
        $end_date = new DateTime($end_date);
        $end_date = date_format($end_date, \'F d, Y\');
    } else {

        $end_date = \'\';
    }
    return apply_filters(\'sep_the_event_end_date\', $end_date, $post);
}

我想更改的日期格式$end_date. 类似“jS M Y”的东西。

我试过这个：

创建了新文件：custom-date-planner.php 并更改了日期格式。

    function custom_sep_get_the_event_end_date($post = NULL) {
        $post = get_post($post);
        if ($post->post_type !== \'event_listing\') {
            return;
        }
        $event_xml = get_post_meta(get_the_ID(), \'event_meta\', TRUE);
        $xml_object = new SimpleXMLElement($event_xml);
        $end_date = isset($xml_object->end_date) ? $xml_object->end_date : \'\';
        $event_date = isset($xml_object->event_date) ? $xml_object->event_date : \'\';
        if (isset($end_date) and \'\'  $end_date and \'checked\'  $event_date) {
            $end_date = isset($xml_object->end_date) ? $xml_object->end_date : \'\';
            $end_date = new DateTime($end_date);
            $end_date = date_format($end_date, \'d M, Y\');
        } else {

            $end_date = \'\';
        }
        return apply_filters(\'custom_sep_the_event_end_date\', $end_date, $post);
    }

接下来是我的功能。php我做到了：

// Add file
require_once(get_stylesheet_directory() . \'/public/partials/custom-date-planner.php\');

add_action( \'after_setup_theme\', \'child_theme_setup\', 100 );
function child_theme_setup() {

    remove_action( \'sep_the_event_end_date\', \'sep_get_the_event_end_date\' );

    add_action( \'sep_the_event_end_date\', \'custom_sep_get_the_event_end_date\' );
}

通过这次跑步，我得到了一个通知：Notice: Trying to get property of non-object in /private/var/www/fashion/data/web/public/wp-content/themes/furnde-child/public/partials/custom-date-planner.php on line 4

我怎样才能让它工作？

post = get_post($post);