Duplicate new categories across multisite network

Question

I'm attempting to setup a MultiSite network, and want the same structure across the sites. This includes Categories.

I've already got code that duplicates Posts - but discovered that if the original post was assigned a category that didn't exist on the other sites in the network,
WP would just "create" a category with the same name (but ignore description, parent etc.).

I've tried to following function - but see no creation of category on other sites in the network.

function category_to_all( $term_id, $tt_id ){

    remove_action( 'create_category', __FUNCTION__ );
    
    $currentcatdata = get_term_by('id', $id, 'category');
    
    // Get & Set Category data ready
    $categorydata = array(
        'cat_ID'               => $term_id,
        'taxonomy'             => 'category',
        'cat_name'             => $currentcatdata->name,
        'category_description' => $currentcatdata->description,
        'category_nicename'    => $currentcatdata->slug,
        'category_parent'      => $currentcatdata->parent,
    );
    
    
    
    // Get all blogs/sites, excluding "current"
    $allsiteids = get_sites(array('fields'  => 'ids'));
    $currentsiteid = get_current_blog_id();
    if (($key = array_search($currentsiteid, $allsiteids)) !== false) {
        unset($allsiteids[$key]);
    }
    $blog_ids = array_values($allsiteids);
    
    foreach( $blog_ids as $blog_id ) {
        switch_to_blog( $blog_id );
        //create category?
    
        wp_insert_term($categorydata['cat_name'], 'category', 
        array(
          'description' => $categorydata['category_description'],
          'slug' => $categorydata['category_nicename'],
          'parent'=> $categorydata['category_parent']
          )
        );
        
        restore_current_blog();
    }
    
    
}
add_action( 'create_category', 'category_to_all', 10, 2 );

The idea is that whenever anyone creates a new category,
it should be duplicated across the other sites (so new posts can go to the corresponding category per-site).

Any pointers or help would be appreciated - TY.

Answer 1

I think I figured it out.
I had multiple things wrong with the code:

function category_to_all( $term_id ){

    remove_action( 'create_category', __FUNCTION__ );
    
    $currentcatdata = get_term_by('id', $term_id, 'category');
    
    
    $allsiteids = get_sites(array('fields'  => 'ids'));
    $currentsiteid = get_current_blog_id();
    if (($key = array_search($currentsiteid, $allsiteids)) !== false) {
        unset($allsiteids[$key]);
    }
    $blog_ids = array_values($allsiteids);
    
    foreach( $blog_ids as $blog_id ) {
        switch_to_blog( $blog_id );
        
        $cid = wp_insert_term($currentcatdata->name, 'category', 
        array(
          'description' => $currentcatdata->description,
          'slug' => $currentcatdata->slug,
          'parent'=> $currentcatdata->parent,
          )
        );
        
        restore_current_blog();
    }
}
add_action( 'create_category', 'category_to_all', 10, 1 );

That seems to work, sort of - whatever blog/site your in on the multisite,
if you create a new category, it gets created on the others as well.
What's missing is handling of "parent" - if the IDs don't match, it will fail to add a new category due to mismatch.