Allow Users to Delete Account (with confirmation message)

<?php

/**
 * User self delete script.
 * 
 * This adds a "delete my account" link to the user profile links
 * created with the [wpmem_profile] shortcode. The user selects and
 * confirms to delete their account and is presented with a success
 * message when the account is deleted.
 */


// Add below this line to functions.php


/**
 * Checks to see if a user is self deleting and if so, after
 * verifying the nonce and form post fields for validity, 
 * the user is deleted.
 */
add_action( 'wpmem_after_init', 'my_user_self_delete' );
function my_user_self_delete () {
    // Verify that the user intended to take this action.
    if ( isset( $_POST['self_delete'] ) && 'delete' == $_POST['self_delete'] ) {
        $nonce = ( isset( $_REQUEST['_wpnonce'] ) ) ? $_REQUEST['_wpnonce'] : false;
        if ( ! wp_verify_nonce( $nonce, 'wpmem_self_delete' ) ) {
            return;
        }
        require_once( ABSPATH . 'wp-admin/includes/user.php' );
        $current_user = wp_get_current_user();
        $wpmem_self_delete = array(
            'self_delete' => 'complete',
            'username' => $current_user->user_login,
        );
        wp_delete_user( $current_user->ID );
        wp_redirect( add_query_arg( $wpmem_self_delete, wpmem_profile_url() ) );
        exit();
    }
}

/**
 * If a user deleted their account, display a success message.
 */
add_filter( 'the_content', 'my_user_self_delete_msg', 999 );
function my_user_self_delete_msg($content){

    if ( isset( $_GET['self_delete'] ) && 'complete' == $_GET['self_delete'] ) {
        $content = wpmem_inc_regmessage( 'self_delete', 'Account deleted for: ' . sanitize_user( $_GET['username'] ) ) . $content;
    }
    return $content;
}


/**
 * This is the member links framework. This adds the user delete
 * link to the member links.  If that action is selected, this
 * displays the form button to validate user deletion.
 */
add_filter( 'wpmem_member_links', 'my_custom_member_links' );
function my_custom_member_links( $links ) {
    
    // Settings.
    $link_text   = 'Delete My Account';
    $return_text = 'Return to User Settings';
    
    /*
     * You probably don't need to change anything below here.
     */
    $process_name = 'delete_my_account'; 
    $return_link  = remove_query_arg( 'a' );
    $return_link  = sprintf( '<p><a href="%s">%s</a></p>', esc_url( $return_link ), $return_text );
    
    // If the page is the custom process page, build and display the form.
    if ( ( isset( $_REQUEST['a'] ) && $process_name == $_REQUEST['a'] ) ) {

        $content = '<p>Do you really want to delete your account?<br />This action is permanent and cannot be undone!</p>
            <p><form name="form" method="post" action="' . esc_url( wpmem_profile_url() ) . '">'
                . wp_nonce_field( 'wpmem_self_delete' )
                . '<input type="hidden" name="self_delete" value="delete" />'
                . '<input type="submit" name="submit" id="submit" class="button button-primary" value="' . $link_text . '"  />'
                . '</form></p>';
        
        // Add a return button.
        $links = $content . $return_link;

    } else {

        $link = add_query_arg( 'a', $process_name, wpmem_profile_url() );
        $new_link = '<li><a href="' . esc_url( $link ) . '">' . $link_text . '</a></li>';
        
        // Add new link at the end of the existing list.
        $links = str_replace( '</ul>', $new_link . '</ul>', $links );
        
    }
    
    return $links;
  }