数据库发生错误。

<?php

class Nextend_Social_Login_Widget extends WP_Widget {

    public static function register() {
        register_widget('Nextend_Social_Login_Widget');
    }

    public function __construct() {
        parent::__construct('nextend_social_login', sprintf(__('%s Buttons', 'nextend-facebook-connect'), 'Nextend Social Login'));
    }

    public function form($instance) {
        $instance = wp_parse_args((array)$instance, array('title' => ''));
        $title    = $instance['title'];

        $style = isset($instance['style']) ? $instance['style'] : 'default';

        $align = isset($instance['align']) ? $instance['align'] : 'left';

        $loginButtons = isset($instance['login-buttons']) ? !!intval($instance['login-buttons']) : true;

        $linkButtons = isset($instance['link-buttons']) ? !!intval($instance['link-buttons']) : false;

        $unlinkButtons = isset($instance['unlink-buttons']) ? !!intval($instance['unlink-buttons']) : false;

        $isPRO = apply_filters('nsl-pro', false);

        ?>
        <p><label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?>
                <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>"
                       name="<?php echo $this->get_field_name('title'); ?>" type="text"
                       value="<?php echo esc_attr($title); ?>"/></label></p>

        <?php if ($isPRO): ?>

            <p>
                <label for="<?php echo $this->get_field_id('style'); ?>"><?php _e('Button style:', 'nextend-facebook-connect'); ?></label><br>
                <input class="widefat" id="<?php echo $this->get_field_id('style_default'); ?>"
                       name="<?php echo $this->get_field_name('style'); ?>" type="radio" value="default"
                       <?php if ($style == 'default'): ?>checked<?php endif; ?>/>
                <label for="<?php echo $this->get_field_id('style_default'); ?>"><?php _e('Default', 'nextend-facebook-connect'); ?></label>
                <br>
                <input class="widefat" id="<?php echo $this->get_field_id('style_icon'); ?>"
                       name="<?php echo $this->get_field_name('style'); ?>" type="radio" value="icon"
                       <?php if ($style == 'icon'): ?>checked<?php endif; ?>/>
                <label for="<?php echo $this->get_field_id('style_icon'); ?>"><?php _e('Icon', 'nextend-facebook-connect'); ?></label>
                <br>
            </p>
        <?php endif; ?>

        <p>
            <label for="<?php echo $this->get_field_id('align'); ?>"><?php _e('Button align:', 'nextend-facebook-connect'); ?></label><br>
            <input class="widefat" id="<?php echo $this->get_field_id('align_left'); ?>"
                   name="<?php echo $this->get_field_name('align'); ?>" type="radio" value="left"
                   <?php if ($align == 'left'): ?>checked<?php endif; ?>/>
            <label for="<?php echo $this->get_field_id('align_left'); ?>"><?php _e('Left', 'nextend-facebook-connect'); ?></label>
            <br>
            <input class="widefat" id="<?php echo $this->get_field_id('align_center'); ?>"
                   name="<?php echo $this->get_field_name('align'); ?>" type="radio" value="center"
                   <?php if ($align == 'center'): ?>checked<?php endif; ?>/>
            <label for="<?php echo $this->get_field_id('align_center'); ?>"><?php _e('Center', 'nextend-facebook-connect'); ?></label>
            <br>
            <input class="widefat" id="<?php echo $this->get_field_id('align_right'); ?>"
                   name="<?php echo $this->get_field_name('align'); ?>" type="radio" value="right"
                   <?php if ($align == 'right'): ?>checked<?php endif; ?>/>
            <label for="<?php echo $this->get_field_id('align_right'); ?>"><?php _e('Right', 'nextend-facebook-connect'); ?></label>
            <br>
        </p>

        <p>
            <input name="<?php echo $this->get_field_name('login-buttons'); ?>" type="hidden" value="0"/>
            <input id="<?php echo $this->get_field_id('login-buttons'); ?>"
                   name="<?php echo $this->get_field_name('login-buttons'); ?>" type="checkbox" value="1"
                   <?php if ($loginButtons): ?>checked<?php endif; ?>/>
            <label for="<?php echo $this->get_field_id('login-buttons'); ?>"><?php _e('Show login buttons', 'nextend-facebook-connect'); ?></label>

        </p>

        <p>
            <input name="<?php echo $this->get_field_name('link-buttons'); ?>" type="hidden" value="0"/>
            <input id="<?php echo $this->get_field_id('link-buttons'); ?>"
                   name="<?php echo $this->get_field_name('link-buttons'); ?>" type="checkbox" value="1"
                   <?php if ($linkButtons): ?>checked<?php endif; ?>/>
            <label for="<?php echo $this->get_field_id('link-buttons'); ?>"><?php _e('Show link buttons', 'nextend-facebook-connect'); ?></label>

        </p>

        <p>
            <input name="<?php echo $this->get_field_name('unlink-buttons'); ?>" type="hidden" value="0"/>
            <input id="<?php echo $this->get_field_id('unlink-buttons'); ?>"
                   name="<?php echo $this->get_field_name('unlink-buttons'); ?>" type="checkbox" value="1"
                   <?php if ($unlinkButtons): ?>checked<?php endif; ?>/>
            <label for="<?php echo $this->get_field_id('unlink-buttons'); ?>"><?php _e('Show unlink buttons', 'nextend-facebook-connect'); ?></label>

        </p>
        <?php
    }

    public function widget($args, $instance) {
        $title = !empty($instance['title']) ? $instance['title'] : '';

        $title = apply_filters('widget_title', $title, $instance, $this->id_base);

        $style = !empty($instance['style']) ? $instance['style'] : 'default';

        $align = !empty($instance['align']) ? $instance['align'] : 'left';

        $loginButtons  = isset($instance['login-buttons']) ? intval($instance['login-buttons']) : 1;
        $linkButtons   = isset($instance['link-buttons']) ? intval($instance['link-buttons']) : 0;
        $unlinkButtons = isset($instance['unlink-buttons']) ? intval($instance['unlink-buttons']) : 0;

        echo $args['before_widget'];
        if ($title) {
            echo $args['before_title'] . $title . $args['after_title'];
        }

        echo do_shortcode('[nextend_social_login style="' . $style . '" login="' . $loginButtons . '" link="' . $linkButtons . '" unlink="' . $unlinkButtons . '" align="' . $align . '"]');

        echo $args['after_widget'];
    }
}

add_action('widgets_init', 'Nextend_Social_Login_Widget::register');