I’ve successfully used the ThreeWP Broadcast plugin to do this on a WPMU installation. The basic concept is that you have one ‘broadcasting’ site from which you can broadcast content to other sites. The content can be posts, pages, custom post types, custom taxonomies, post meta or attachments. If content is updated on the ‘broadcasting’ … Read more
WordPress distinguishes usermeta keys between sites by using the database prefix for each site. For example, instead of using the favorite_posts key, you’d use the meta key wp_23_favorite_posts. To get the prefix, you can use $wpdb->get_blog_prefix(). But wait, there’s actually a whole API dedicated to this. Rather than using *_user_meta(), use *_user_option(). These are internally … Read more
A Multi-Domain (UCC) SSL certificate will allow your users to choose their own domain to display. It may be important for you to know that many Certificate Authorities have a limit to the number of certificates that can be issued for a single IP address so if you are running a large network of over … Read more
WordPress: Can I add categories/tags to all sites in my network at once?
With Multisite, you need to use add_site_option/get_site_option instead of add_option/get_option. https://codex.wordpress.org/Function_Reference/get_site_option
You might check in General Settings: Home URL should be http://example.com Site URL should be http://example.com/wp When you open http://example.com, what URL does it show for …/twentythirteen/style.css? Do you see the “broken” URL http://example.com/wp/test-network-site/wp-content/themes/twentythirteen/style.css in the source? If so, it suggests WordPress might be using a wrong path (not necessarily nginx). I think that should … Read more
I created a plugin which does something similar (called Multisite Post Display https://wordpress.org/plugins/multisite-post-reader/ ) . It displays posts from all multisite sub-sites. The code in there might be helpful for what you are doing. You are welcome to dig into it and use the code to help with your project. (After all, I used other … Read more
Potential Issues Google’s Page Speed service does not work with “naked domains”. That is, it will not work with just “example.com”. The domain name must have a subdomain in front of it, such as “www.example.com”. This is due to a limitation on Google’s implementation of the Page Speed service, which requires you to set up … Read more
What @petermolnar suggested also redirects your users to the main site if they want to register (I’ve tested this but feel free to make use of it. It’s good practice). What you need is a registration/login/edit-profile plugin for the front end: http://www.cozmoslabs.com/1341-wordpress-profile-builder-a-front-end-user-registration-login-and-edit-profile-plugin/ It’s shortcode based so all you have to do is redirect your users … Read more
Here’s an example of a solution I configured, which leaves the site in the network, but establishes a domain map from any registered domain, to the network. It makes the network site appear to be a completely independent site, with all the functionality (log-in, etc.) intact. Goal: Map client’s registered domain, both www.foosite.com and foosite.com … Read more