Replace plugin function with a custom function?

Question

How can I replace a function from a plugin with a custom version of it.

The original function of the plugin is:

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);
}

I want to change the date format of $end_date. Something like 'jS M Y'.

I tried this:

Created a new file: custom-date-planner.php and changed the date format.

    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);
    }

Next in my functions.php I did this:

// 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' );
}

With this running, I get the notice: 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

How can I get this to work?

Answer 1

For your question how can I replace this function . You don't need to replace it. The function has a filter on the returns value, not an action. You don't need to remove it, just filter the result.

So you can create a new function and call it with add_filter('sep_the_event_end_date', 'yourfunction'); Put this in your functions.php file without the add_action plugin _loaded.

Answer 2

In the function that you are using as a replacement. You don't get the post data, or did you just left that out?

post = get_post($post);

Answer 3

It seems the $post parameter isn't always correct.

Maybe a double check.

Change this:
if ($post->post_type !== 'event_listing') {
Into this:
if ( ! isset($post->post_type) || $post->post_type !== 'event_listing' ) {