Modify function to only return values for the user that’s logged in

Question

I'm trying to modify a function in a plugin so that it only returns the custom post type (venues) of the user that’s logged in (by default it displays all venues). This is my first time customizing a function, so any help would be greatly appreciated!

This is what I've put into my functions.php file:

global $current_user;
get_currentuserinfo();

if ($post->post_author == $current_user->ID) {
    add_action('tribe_events_community_form', 'community_events_venue_select_menu_current_user');
function community_events_venue_select_menu_current_user( $event_id = null ) {
 if ( !$event_id ) {
     global $post;
     if( isset( $post->post_type ) && $post->post_type == 'tribe_events' ) {
         $event_id = $post->ID;
     } elseif( isset( $post->post_type ) && $post->post_type == 'tribe_venue' ) {
         return;
     }
 }
 do_action( 'tribe_venue_table_top', $event_id );
}
}

I'm getting the following two errors for the function, even though there are thousands of the 'tribe_events' and 'tribe_venue' post types in my database:

Notice: Undefined variable: post

Notice: Trying to get property of non-object

on this line: if ($post->post_author == $current_user->ID) {

---

Additionally, when I changed the name of the default function (in the plugin) to my custom function name, its returning this error:

Fatal error: Call to undefined function community_events_venue_select_menu_current_user()

Answer 1

See below for my version of what you are trying to do. However keep in mind that adding this function to your functions.php, and changing the plugin to point to this function, will produce an error that the function does not exist. This is because plugins are included before functions.php, so when the plugin loads your function doesn't exist yet. You will need to make this change inside the plugin itself.

Modifying plugins is generally not a great idea because as the plugin updates it will overwrite your changes. If you think that it is still a good idea in your case, I would suggest changing the name of the plugin, or setting the version number very high to prevent updates from breaking your code. Of course from then on it will be up to you to manually update/maintain the custom version of the plugin as needed.

function community_events_venue_select_menu_current_user( $event_id = null ) {

    global $current_user, $post;
    get_currentuserinfo();

    if ( $post->post_author != $current_user->ID ) {
        return; // Do nothing if this post author does not match our current user id
    }

    if ( ! $event_id ) {
        if ( isset( $post->post_type ) && $post->post_type == 'tribe_events' ) {
            $event_id = $post->ID;
        } elseif ( isset( $post->post_type ) && $post->post_type == 'tribe_venue' ) {
            return;
        }
    }
    do_action( 'tribe_venue_table_top', $event_id );
}
add_action( 'tribe_events_community_form', 'community_events_venue_select_menu_current_user' );

Answer 2

Use get_currentuserinfo(); to pull the current user's ID, then check it against $post->post_author with an if statement.

global $post, $current_user;
get_currentuserinfo();

if ($post->post_author == $current_user->ID) {
    // Do something
}

There should be an add_action either directly before or after the function; place that line inside the if statement so the function is only registered if the author condition is true.

For your case, use the following:

add_action('tribe_events_community_form', 'community_events_venue_select_menu_current_user');
function community_events_venue_select_menu_current_user( $event_id = null ) {
    global $post, $current_user;
    get_currentuserinfo();

    if ($post->post_author == $current_user->ID) {
        if ( !$event_id ) {
            if( isset( $post->post_type ) && $post->post_type == 'tribe_events' ) {
                $event_id = $post->ID;
            } elseif( isset( $post->post_type ) && $post->post_type == 'tribe_venue' ) {
                return;
            }
        }
        do_action( 'tribe_venue_table_top', $event_id );
    }
}