WP Weixin Crossdomain Nexus - Customize the blog ID used for WeChat API authentication calls when using a subdomain-based multisite network

wp-weixin-crossdomain-nexus.php

<?php
/*
Plugin Name: WP Weixin Crossdomain Nexus
Plugin URI: https://gist.github.com/froger-me/c918d7f2c4f88eff1b330a50d8962f23
Description: Requires WP Weixin. Customize the blog IDs used for WeChat API authentication and WeChat Pay transactions when using a domain/subdomain-based multisite network. NEEDS TO BE EDITED BY A DEVELOPER BEFORE USE!
Version: 1.3.5
Author: Alexandre Froger
Author URI: https://froger.me
WC tested up to: 3.8.1
*/

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

/* ============================================================================ *
 * 								Complex Example									*
 *																				*
 * 							Multiple Official Accounts 							*
 * ============================================================================ */

// 2 WeChat Official Accounts (OA):
// - the first one uses blog with ID 1 for both authentication and payment
// - the second one uses blog with ID 2 for both authentication and payment
// - the WeChat App IDs used to determine which OA to use depending on the current
//   blog ID are hard coded in this example, but they could come from
//   get_site_option() if the developer building on this example creates a setting page.
// - it is assumed the ID of the blog used for authentication before this plugin was
//   activated was the default blog with ID 1 (therefore no usermeta table update is
//   necessary, all existing users are users of the first OA).

function wpwxdn_wechat_set_id( $blog_id ) {
	$official_account_appid_1 = 'EDIT ME !!!'; // The WeChat App ID of the first OA
	$official_account_appid_2 = 'EDIT ME !!!'; // The WeChat App ID of the second OA

	$current_official_account_appid = wp_weixin_get_option( 'appid' );

	if ( $current_official_account_appid === $official_account_appid_1 ) {
		$blog_id = 1;
	}

	if ( $current_official_account_appid === $official_account_appid_2 ) {
		$blog_id = 2;
	}

	return $blog_id;
}
add_filter( 'wp_weixin_ms_auth_blog_id', 'wpwxdn_wechat_set_id', 10, 1 );