Add Multisite support for user data in WordPress. Thanks to @peter-tmann for the submission.

[peter-tmann]

Added lines 209-230 to check for WP Multisite installation.

If it's a Multisite, then the 'user' object will be accessed using the 'wpdb->base_prefix' because the 'user' table is the same across all sites and just 'wpdb->prefix' does not work.

If it's not a Multisite, then the previous code executes.

What does this Pull Request do?

Adds WP Multisite compatibility for the 'user' object

How do I test this Pull Request?

Install the plugin on WP Multisite installation. Create a Fieldmap with the 'user' WordPress object (current version of plugin doesn't work at this point)

[jonathanstegall]

@peter-tmann Can you speak to whether this kind of code is necessary on other WordPress objects, or if it's only needed on the user object?

[jonathanstegall]

(Related to issue #179, although I'm not sure how big the scope of that issue is vs how limited this fix is.)

[peter-tmann]

This is only needed on the user object because the user table is the same across all sites in a Multisite installation and therefore needs to be accessed using the base prefix. For all other objects, wpdb->prefix will retrieve the correct table for the site in a Multisite installation.

The plugin is running with this modification on our Multisite installation and that was the only issue I came across so far.

[jonathanstegall]

@peter-tmann thank you. In that case, I suggest overwriting the array values that are different, rather than duplicating so much code. Like this:

$object_table_structure = array(
    'object_name'     => 'user',
    'content_methods' => array(
        'create' => 'wp_insert_user',
        'read'   => 'get_user_by',
        'update' => 'wp_update_user',
        'delete' => 'wp_delete_user',
        'match'  => 'get_user_by',
    ),
    'meta_methods'    => $user_meta_methods,
    'content_table'   => $this->wpdb->prefix . 'users',
    'id_field'        => 'ID',
    'meta_table'      => $this->wpdb->prefix . 'usermeta',
    'meta_join_field' => 'user_id',
    'where'           => '',
    'ignore_keys'     => array( // Keep it simple and avoid security risks.
        'user_pass',
        'user_activation_key',
        'session_tokens',
    ),
);

// Check for Multisite installation. Sitewide User table uses base site prefix across all sites.
if ( is_multisite() ) {
    $object_table_structure['content_table'] = $this->wpdb->base_prefix . 'users';
    $object_table_structure['meta_table']    = $this->wpdb->base_prefix . 'usermeta';
}

Can you see if this works in your testing, and if it does, edit your pull request to that effect?

[peter-tmann]

@jonathanstegall, Good point. I'll make the change on our site today and update the pull request if it tests OK.

[peter-tmann]

@jonathanstegall, I updated and tested the code on our site and everything is working. I updated the file in my fork, so it's up to date for the pull request.