acf-multisite-options.php

<?php
/*
Plugin Name: ACF Multisite Options
Plugin URI: https://owlwatch.com
Description: Allow multisite options pages
Author: Mark Fabrizio
Version: 2.0.1
Author URI: http://owlwatch.com/
*/

namespace ACF\Multisite\Options;

/**
 * This plugin provides functionality for Network level options
 * pages using the normal ACF API
 */
class Plugin{
	
	/**
	 * flag used to indiciate when we need to filter options pages
	 * @var boolean
	 */
	private $_filter_options_pages = false;
	
	/**
	 * capture 'network' pages
	 */
	private $_network_pages = [];
	
	/**
	 * cache the current site
	 */
	private $_current_site;
	
	/**
	 * field types that require a "blog id" (like image, post, etc)
	 * @var array
	 */
	private $_blog_specific_field_types = [];
	
	/**
	 * Singleton pattern
	 */
	public static function getInstance(){
		static $instance;
		if(!isset($instance)){
			$instance = new self();
		}
		
		return $instance;
	}
	
	/**
	 * Wait until plugins are loaded so we can ensure ACF is available
	 */
	protected function __construct(){
		add_action('acf/init', [$this, 'init'], 1);
	}
	
	/**
	 * Setup the plugin hooks
	 * @return void
	 */
	public function init(){
		
		if(!function_exists('acf_options_page')){
			return;
		}
		
		$this->_blog_specific_field_types = apply_filters('acf/multisite/blog_specific_field_types', [
			'post',
			'relationship',
			'image',
			'file',
		]);
		
		$this->_current_site    = get_current_site();
		$acf_admin_options_page = $this->get_acf_admin_options_page();
		
		if(is_admin() && $acf_admin_options_page){
			
			// Run the ACF Options admin_menu function on network menu
			add_action('network_admin_menu', [$acf_admin_options_page, 'admin_menu'], 99, 0);
			
			// Filter out pages by "network" attribute when loading the pages
			// for the admin_menu depending on the context
			add_action('admin_menu', [$this, 'before_admin_menu'], 1);
			add_action('network_admin_menu', [$this, 'before_admin_menu'], 1);
			add_filter('acf/get_options_pages', [$this, 'filter_options_pages']);
			
		}
		
		add_filter('acf/validate_options_page', [$this, 'capture_network_pages'], 3000);
		add_filter('acf/pre_load_post_id', [$this, 'convert_post_id'], 10, 2);
		
		// Wrap some fields with "switch_to_blog()" calls to retrieve images/ posts
		add_filter('acf/format_value', [$this, 'format_value_start'], 1, 3);
		add_filter('acf/format_value', [$this, 'format_value_end'], 999, 3);
		
		// lets add an option for the blog to specify for these
		add_action('acf/render_field_settings', [$this, 'add_blog_setting'], 10, 1);
		
	}
	
	public function capture_network_pages($page){
		if(isset($page['network']) && $page['network']){
			$this->_network_pages[$page['post_id']] = $page;
		}
		
		return $page;
	}
	
	public function convert_post_id($preload, $post_id){
		if(is_numeric($post_id)){
			return $preload;
		}
		
		if($post_id && is_string($post_id) && is_scalar($post_id) && isset($this->_network_pages[$post_id])){
			return 'site_' . $this->_current_site->id;
		}
		
		return $preload;
	}
	
	/**
	 * Sneaky way to get the instantiated "$acf_admin_options_page" object
	 * as it does not have a global reference.
	 *
	 * @return mixed Returns either the page array or false
	 */
	public function get_acf_admin_options_page(){
		static $acf_admin_options_page = null;
		if(isset($acf_admin_options_page)){
			return $acf_admin_options_page;
		}
		$acf_admin_options_page = false;
		global $wp_filter;
		if(empty($wp_filter['admin_menu']) || empty($wp_filter['admin_menu'][99])){
			return $acf_admin_options_page;
		}
		foreach($wp_filter['admin_menu'][99] as $hook){
			if(is_array($hook['function']) && get_class($hook['function'][0]) === 'acf_admin_options_page'){
				$acf_admin_options_page = $hook['function'][0];
				break;
			}
		}
		
		return $acf_admin_options_page;
	}
	
	/**
	 * Enabling page filtering for the acf_get_options_pages function
	 * when we are in the admin menu
	 * @return void
	 */
	public function before_admin_menu(){
		$this->_filter_options_pages = true;
	}
	
	/**
	 * Filter the options pages depending on the context, network or not network.
	 *
	 * @param array $pages ACF options pages
	 *
	 * @return array  The filtered pages.
	 */
	public function filter_options_pages(array $pages){
		if(!$this->_filter_options_pages){
			return $pages;
		}
		
		$this->_filter_options_pages = false;
		
		return array_filter($pages, function($page){
			return is_network_admin() ? !empty($page['network']) : empty($page['network']);
		});
	}
	
	/**
	 * Retrieve an options page by its "post_id" attribute
	 *
	 * There could be multiple pages with the same post_id,
	 * but we require that network pages either share a post_id
	 * or each have their own.
	 *
	 * @param string $post_id the ACF post_id
	 *
	 * @return mixed the options page or false if none found
	 */
	public function get_options_page_by_post_id($post_id){
		$pages = acf_get_options_pages();
		foreach($pages as $page){
			if(!empty($page['post_id']) && $page['post_id'] === $post_id){
				return $page;
			}
		}
		
		return null;
	}
	
	public function format_value_start($value, $post_id, $field){
		if(!empty($field['mulitisite_blog_id'])){
			switch_to_blog($field['mulitisite_blog_id']);
		}
		
		return $value;
	}
	
	public function format_value_end($value, $post_id, $field){
		if(!empty($field['mulitisite_blog_id'])){
			restore_current_blog();
		}
		
		return $value;
	}
	
	public function add_blog_setting($field){
		if(!in_array($field['type'], $this->_blog_specific_field_types)){
			return;
		}
		
		// otherwise, lets add that setting...
		$sites   = get_sites();
		$choices = [];
		foreach($sites as $site){
			$choices[$site->blog_id] = $site->domain . $site->path;
		}
		
		acf_render_field_setting($field, [
			'label'        => __('Site'),
			'instructions' => '',
			'name'         => 'multisite_blog_id',
			'type'         => 'select',
			'allow_null'   => false,
			'ui'           => 1,
			'default'      => get_main_site_id(),
			'choices'      => $choices,
		], true);
	}
	
}

// Instantiate our plugin
Plugin::getInstance();