Sharing site info across the network

Sharing site info across the network.php

<?php
/*
Plugin Name: Share across network
Plugin URI: http://premium.wpmudev.org/
Description: A very simple widget plugin to share info across the network
Version: 1.0.1
Author: Ashok (Incsub)
Author URI: http://bappi-d-great.com
License: GNU General Public License (Version 2 - GPLv2)
Network: true
*/

/*
 * Translation is not ready
 */

namespace shareinfo; 
use \WP_Widget as WP_Widget;
 
if ( ! defined( 'ABSPATH' ) ) exit;

if( ! class_exists( 'share_info' ) ){
    
    class share_info{
        
        public function __construct() {
            add_action( 'network_admin_menu', [ $this, 'site_info_page' ] );
        }
        
        
        public function site_info_page() {
            add_submenu_page( 'sites.php', 'Site Info', 'Site Info', 'manage_network', 'site-info', [ $this, 'site_info_page_cb' ] );
        }
        
        
        public function site_info_page_cb() {
            
            if( $_POST['share_info_submit'] ){
                
                if( ! is_super_admin() ){
                    return;
                }
                
                if ( ! isset( $_POST['share_info_nonce_field'] ) || ! wp_verify_nonce( $_POST['share_info_nonce_field'], 'share_info_action' ) ) {
                    return;
                }
                
                if( update_site_option( 'share_site_info', $_POST['share_info'] ) )
                    wp_redirect( admin_url( 'network/sites.php?page=site-info&msg=Data+Saved.' ) );
                
            }
            
            $sites = wp_get_sites();
            
            $info = get_site_option( 'share_site_info' );
            
            ?>
            <div class="wrap">
                <h2>Add the data you want to share for all sites</h2>
                <br>
                <?php if( $_REQUEST['msg'] ) { ?>
                <div id="message" class="updated below-h2"><p><?php echo str_replace( '+', ' ', $_REQUEST['msg'] ) ?></a></p></div>
                <?php } ?>
                <form action="<?php echo admin_url( 'network/sites.php?page=site-info&noheader=true' ) ?>" method="post">
                    <?php wp_nonce_field('share_info_action','share_info_nonce_field'); ?>
                    <table class="widefat">
                        <tr>
                            <th width="25%">Site name</th>
                            <th>Site info</th>
                        </tr>
                        <?php
                            $i = 0;
                            foreach( $sites as $site ) {
                                switch_to_blog( $site['blog_id'] ); ?>
                                <tr class="<?php echo $i++ % 2 == 0 ? 'alternate' : '' ?>">
                                    <td><?php echo get_bloginfo( 'name' ); ?></td>
                                    <td>
                                        <textarea style="width: 100%" rows="5" name="share_info[<?php echo $site['blog_id'] ?>]"><?php echo $info[$site['blog_id']] ?></textarea><br><em>HTML Allowed</em>
                                    </td>
                                </tr>
                            <?php
                                restore_current_blog();
                                }
                            ?>
                    </table>
                    <br>
                    <input type="submit" name="share_info_submit" class="button button-primary" value="Save">
                </form>
            </div>
            <?php
        }
        
    }
    
    new share_info();
    
}

if( ! class_exists( 'Share_Info_Widget' ) ) {
	
	class Share_Info_Widget extends WP_Widget{
		
		/**
		 * Sets up the widgets name etc
		 */
		public function __construct() {
			parent::__construct(
				'share_info_widget', // Base ID
				__( 'Share Static Content across Multisite' ), // Name
				array( 'description' => __( 'A widget to share static content' ), ) // Args
			);
		}
		
		
		/**
		 * Outputs the content of the widget
		 *
		 * @param array $args
		 * @param array $instance
		 */
		public function widget( $args, $instance ) {
			
			echo $args['before_widget'];
			if ( ! empty( $instance['title'] ) ) {
				echo $args['before_title'] . apply_filters( 'widget_title', $instance['title'] ). $args['after_title'];
                                $sites = wp_get_sites();
                                $info = get_site_option( 'share_site_info' );
                                $id = get_current_blog_id();
                                
                                foreach( $sites as $site ){
                                    if( $site['blog_id'] == $id ) continue;
                                    switch_to_blog( $site['blog_id'] );
                                    ?>
                                    <ul>
                                        <li>
                                            <h4><?php echo get_bloginfo( 'name' ); ?></h4>
                                            <p><?php echo $info[$site['blog_id']] ?></p>
                                        </li>
                                    </ul>
                                    <?php
                                    restore_current_blog();
                                }
                                
			}
			echo $args['after_widget'];
			
		}
		
		
		/**
		 * Outputs the options form on admin
		 *
		 * @param array $instance The widget options
		 */
		public function form( $instance ) {
			
			$title = ! empty( $instance['title'] ) ? $instance['title'] : __( 'Site Information' );
			
			?>
			
			<p>
				<label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
				<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 ); ?>">
			</p>
			
			<?php
			
		}


		/**
		 * Processing widget options on save
		 *
		 * @param array $new_instance The new options
		 * @param array $old_instance The previous options
		 */
		public function update( $new_instance, $old_instance ) {
			
			$instance = array();
			$instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';
			
	
			return $instance;
			
		}
		
	}

	add_action( 'widgets_init', function() {
		register_widget( 'shareinfo\Share_Info_Widget' );
	} );
	
}