automatic publish node to main domain from subdomain

I have read several issue like this in D6 version.
I can't write a code so i don't know how difficulty to realize it, but i think is very good to add this feature in this version.

if you don't mind i'd like to post an idea:
is it possible to add this feature in "domain setting"
at under fieldset "Send to all affiliates" and at upper "Debugging status".

The form for this feature is like "Send to all affiliates" fieldset but with a title something like "Send to all assigned domain".

or to add a permission under "Publish content to any assigned domain " with a title something like "Publish content to assigned domain ".

So user with this permission will automaticaly publish their content to all selected affiliates domain for this user.

I'm sure there are a lot of user need this feature.

One more time, thanks a ton for released this module.

I'd like to create a site with around 100 teacher in a school.
each teacher need a subdomain.
They want to publish book node from every subdomain to main domain.

is your code in http://drupal.org/node/922410#comment-3492328 work in 7.x-3.dev version ?
i'm not a coder but i've try to create a submodule named domain_custom_affiliate with 2 file: domain_custom_affiliate.info and domain_custom_affiliate.module.
Then i copied your code to be

// This assumes you have a module named domain_custom_affiliate.module.
function domain_custom_affiliate_domainrecords(&$grants, $node) {
  global $_domain;
  // We only care about the book_type node.
  if ($node->type != 'book') {
    return;
  }
  $primary_set = FALSE;
  foreach ($grants as $key => $grant) {
    // Remove the domain_site grant.
    if ($grant['realm'] == 'domain_site') {
      unset($grants[$key]);
    }
    // Remove domains we don't want.
    else if ($grant['gid'] != $_domain['domain_id']) {
      unset($grants[$key]);
    }
    // Check that the primary domain is set.
    if ($grant['gid'] == 0 && $grant['realm'] == 'domain_id') {
      $primary_set = TRUE;
    }
  }
  // Make sure the primary domain is selected.
  if (!$primary_set) {
    $grants[] = array(
      'realm' => 'domain_id',
      'gid' => 0,
      'grant_view' => TRUE,
      'grant_update' => TRUE,
      'grant_delete' => TRUE,
      'priority' => 0,
    );
  }
}

installed it without an error but this module is not working.

If this code is not complete, would you help us to completed this module so we could use it as a quick solution ?
Thank in advance, and i very appreciate for your help.
Apologize if this request excessive.

function domain_custom_affiliate_node_access_records_alter(&$grants, $node) {
  global $_domain;
  // We only care about the book node.
  if ($node->type != 'book') {
    return;
  }
  $primary_set = FALSE;
  foreach ($grants as $key => $grant) {
    // Remove the domain_site grant.
    if ($grant['realm'] == 'domain_site') {
      unset($grants[$key]);
    }
    // Remove domains we don't want.
    else if ($grant['gid'] != $_domain['domain_id']) {
      unset($grants[$key]);
    }
    // Check that the primary domain is set.
    if ($grant['gid'] == 0 && $grant['realm'] == 'domain_id') {
      $primary_set = TRUE;
    }
  }
  // Make sure the primary domain is selected.
  if (!$primary_set) {
    $grants[] = array(
      'realm' => 'domain_id',
      'gid' => 0,
      'grant_view' => TRUE,
      'grant_update' => TRUE,
      'grant_delete' => TRUE,
      'priority' => 0,
    );
  }
  // Store our records in the {domain_access} table.
  _domain_store_grants($node->nid, $grants);
}

This is my latest modification.
saved book node from sub domain is still do not automatically publish to main domain.
Please, i need any advice.

Thanks a lot for your advice !!!
This is my latest code, i can automatic publish book page from subdomain and automatically publish it to main domain.

function domain_custom_affiliate_node_access_records_alter(&$grants, $node) {
  global $_domain;
  // We only care about the book node.
  if ($node->type != 'book') {
    return;
  }
  $primary_set = FALSE;
  foreach ($grants as $key => $grant) {
    // Remove the domain_site grant.
    if ($grant['realm'] == 'domain_site') {
      unset($grants[$key]);
    }
    // Remove domains we don't want.
    else if ($grant['gid'] != $_domain['domain_id']) {
      unset($grants[$key]);
    }
    // Check that the primary domain is set.
    if ($grant['gid'] == 0 && $grant['realm'] == 'domain_id')  {
      $primary_set = TRUE;
    }
  }
  // Make sure the primary domain is selected.
  if (!$primary_set) {
	// Always publish all content to the primary domain.
	$grants[] = array(
		'realm' => 'domain_id',
		'gid' => domain_default_id(),
		'grant_view' => $node->status,
		'grant_update' => 1,
		'grant_delete' => 1,
		'priority' => 0,
	);
  }
  // Store our records in the {domain_access} table.
  _domain_store_grants($node->nid, $grants);
}

is it will be an additional feature for domain access ?