What is the correct form action URL for network options pages?

Question

Referring to Settings API in Multisite - Missing update message

It states that:

For network option pages the correct form action URL is:

wp-admin/network/edit.php?action=your_option_name

Note: without a '/' in front

Okay. Let's try it:

<form method="post" action="wp-admin/network/edit.php?action=your_option_page">

Obviously, my options form actually gets submitted to:

http://yourdomain.com/wp-admin/network/wp-admin/network/edit.php?action=your_option_page

Now, adding a '/' in front:

<form method="post" action="/wp-admin/network/edit.php?action=your_option_page">

Submits the form (correctly) to:

http://yourdomain.com/wp-admin/network/edit.php?action=your_option_page

That's right in most cases, I think?

However, I got feedback from some of the users of my plugin, that they get this when submitting the options form:

Not Found The requested URL /wp-admin/network/edit.php was not found on this server.

Is this due to incorrect server configuration for that user, or should I actually stick to the following form action URL to make it work with different server paths:

<form method="post" action="edit.php?action=your_option_page">

Form still submits to correct URL:

http://yourdomain.com/wp-admin/network/edit.php?page=your_option_page

Would the latter form action URL work in all install paths that wordpress supports? (with subdomains, directory paths, etc.). How about the different web servers: Apache, Nginx, IIS

yourdomain.com yourdomain.com/wordpress/ subdomain.yourdomain.com subdomain/yourdomain.com/wordpress/

Answer 1

When referring to urls within the network-admin, you should consider the network_admin_url(). core function, that falls back to admin_url() for non-multisite setups.

So try this, using add_query_arg just as @toscho uses in the answer OP links to:

echo esc_url( 
    add_query_arg( 
       'action', 
       'your_option_name', 
       network_admin_url( 'edit.php' ) 
    ) 
);

instead of hard-coding it with possible wrong assumptions of the install path.

Here we escape the output for use in the HTML action attribute.