[Support request] Two bugs with the swpm_auto_redirect_non_members() hook provided.

I am getting this (seemingly common) GutenbergEditor error.

Everything seems to work, but WordPress fails to update when you try in backend.

Updating failed. Error message: The response is not a valid JSON response.

The error difficult to track down as it isn’t debugged or logged anywhere and the most common advice is uninstall plugins and themes.

I tracked the error down to these lines of code. From this link. https://simple-membership-plugin.com/auto-redirect-non-logged-in-users-protect-whole-site/

add_filter( 'pre_get_posts', 'swpm_auto_redirect_non_members' );
function swpm_auto_redirect_non_members() {
    if (is_admin()){
        //Inside the admin dashboard. Nothing to do.
        return;
    }
    //We are on the front-end. Lets check visitor's login status.
    if( !SwpmMemberUtils::is_member_logged_in() && !is_page( array( '', 'login' )) ) {
        wp_redirect( 'http://www.your-domain.com/membership-login' );
        exit;
    }
}

I managed to solve the problem in the backend by reverting to the code you provided previously.

/***  Auto redirect a user who isn't logged into the site  ***/
add_filter( 'pre_get_posts', 'swpm_auto_redirect_non_members' );
function swpm_auto_redirect_non_members() {

    if (is_admin()){
        // I added this block after seeing swpm use it. I don't think was here originally
        // Inside the admin dashboard. Nothing to do.
        return false;
    }

    if( !SwpmMemberUtils::is_member_logged_in() && !is_page( array( '', 'login' ) ) && !current_user_can('administrator') ) {
        wp_redirect( 'https://www.your-domain.com/' );
        exit;
    }
}

So fortunately everything seems to be working again.

I am intrigued into what actually causes this error, perhaps you may know? I can reproduce it on my site. Perhaps you won’t be able to.

But I tried uninstalling all the other plugins to fix this problem before finding the solution. I am really curious to know about this particular error as it’s so closely related with the Gutenberg Editor and hard to track/debug. I may mention it on WP Stackoverflow. If it’s okay with you ?

I have also noticed that these lines of code for a redirect none logged in users will also cause a PHP warning / notice on the front-page.

[05-Feb-2020 21:13:02 UTC] PHP Notice:  Trying to get property 'ID' of non-object in /home/sites/3a/5/5af1210914/public_html/wp-includes/class-wp-query.php on line 3965

https://core.trac.wordpress.org/ticket/21790
https://core.trac.wordpress.org/ticket/27015

I found the solution below at the above tickets. Would it not be possible to place this filter in a different wordpress function??

/***  Auto redirect a user who isn't logged into the site  ***/
add_filter( 'pre_get_posts', 'swpm_auto_redirect_non_members' );
function swpm_auto_redirect_non_members($query) {

    $front_page_id        = get_option( 'page_on_front' );
    $current_page_id      = $query->get( 'page_id' );
    $is_static_front_page = 'page' == get_option( 'show_on_front' );

    if ( $is_static_front_page && $front_page_id == $current_page_id  ) {
        error_log( 'is static front page and current page is front page' );
        return;
    }

    if (is_admin()){
        // Inside the admin dashboard. Nothing to do.
        return;
    }

    if( !SwpmMemberUtils::is_member_logged_in() && !is_page( array( '', 'login' ) ) && !current_user_can('administrator') ) {
        wp_redirect( 'https://www.your-domain.com/' );
        exit;
    }
}