PHP Warning: Declaration of aec_contributor_list::form() should be compatible with WP_Widget::form($instance)

Question

Ajax Event Calendar plugin is no longer update, but I receive this error.

PHP Warning: Declaration of aec_contributor_list::form() should be compatible with WP_Widget::form($instance) in /home/soso2358/public_html/wp-content/plugins/ajax-event-calendar/inc/widget-contributors.php on line 64

Below is the code for widget-contributors.php

<?php
class aec_contributor_list extends WP_Widget {

    function aec_contributor_list () {
        $widget_ops = array('description' => __('A list of calendar contributors linked to their organization websites', AEC_NAME));
        parent::WP_Widget(false, __('AEC Contributors', AEC_NAME), $widget_ops);
    }
    
    function widget ($args, $instance) {
        extract($args);
        $contributors = $this->db_query_users_by_role('calendar_contributor');
        echo $before_widget;
        $conts = sizeof($contributors);
        echo $before_title . sprintf(_n('(%d) Contributor','(%d) Contributors', $conts, AEC_NAME), $conts) . $after_title;
        if ($contributors) {
            echo '<ul>';
            foreach ($contributors as $contributor){
                $user = get_userdata($contributor);
                echo '<li><a href="' . $user->user_url . '" target="_blank">' .  $user->organization . '</a></li>';
            }
        }else{
            _e('No contributors as of yet.', AEC_NAME);
        }
        echo '</ul>';
        echo $after_widget;
    }

    function db_query_users_by_role ($roles) {
        global $wpdb;
        if (!is_array($roles)) {
            $roles = explode(",", $roles);
            array_walk($roles, 'trim');
        }
        $sql = '
            SELECT  ID, display_name
            FROM    ' . $wpdb->users . ' INNER JOIN ' . $wpdb->usermeta . '
            ON      ' . $wpdb->users . '.ID =       ' . $wpdb->usermeta . '.user_id
            WHERE   ' . $wpdb->usermeta . '.meta_key =  \'' . $wpdb->prefix . 'capabilities\'
            AND     (
        ';
        $i = 1;
        foreach ($roles as $role) {
            $sql .= ' ' . $wpdb->usermeta . '.meta_value    LIKE    \'%"' . $role . '"%\' ';
            if ($i < count($roles)) {
                $sql .= ' OR ';
            }
            $i++;
        }
        $sql .= ') ';
        $sql .= ' ORDER BY display_name ';
        $userIDs = $wpdb->get_col($sql);
        return $userIDs;
    }

    
    /** @see WP_Widget::form */
    function form () {              
        _e('No options available.', AEC_NAME);
    }
}
add_action('widgets_init', create_function('', 'return register_widget("aec_contributor_list");'));
?>

Answer 1

WP_Widget::form() expects to receive an array as a parameter, but the plugin's form() function doesn't have it.

You can probably fix it like this:

/** @see WP_Widget::form */
function form ( $instance ) {              
    _e('No options available.', AEC_NAME);
}

Be aware, though, that if the plugin's not supported by its developers anymore, there won't be any security updates.