Automatically putting a user's post into an organic group

The final result is in the (as yet unreleased, but if you want the code we'll send it) special treatment module.

Some test ouput and discovery of key function along the way:

<?php
'og_groups' =>
  array (
    11054 =>
    array (
      'title' => 'A Center for Development and Entrepreneurship',
      'type' => 'partner',
      'status' => '1',
      'nid' => '11054',
      'og_role' => '0',
      'is_active' => '1',
      'is_admin' => '1',
      'uid' => '1',
      'mail_type' => NULL,
      'created' => '1222100233',
      'changed' => '1222280936',
    ),
  ),
   'og_email' => '2',

'og_groups' => array ( ), 'og_email' => '1', ))
?>

For user #1, editing an existing form:

<?php
  'og_initial_groups' =>
  array (
    '#type' => 'value',
    '#value' => NULL,
  ),
  'og_nodeapi' =>
  array (
    'visible' =>
    array (
      'og_groups' =>
      array (
        '#type' => 'checkboxes',
        '#title' => 'Audience',
        '#attributes' =>
        array (
          'class' => 'og-audience',
        ),
        '#options' =>
        array (
          11054 => 'A Center for Development and Entrepreneurship',
        ),
        '#required' => false,
        '#description' => 'Show this post in this group.',
        '#default_value' => NULL,
        '#multiple' => true,
      ),
    ),
  ),
?>

When there's a value:

<?php
  'og_initial_groups' =>
  array (
    '#type' => 'value',
    '#value' =>
    array (
      0 => 11054,
    ),
  ),
?>

For a regular user:

<?php
  'og_invisible' =>
  array (
    'og_groups_inaccessible' =>
    array (
      '#type' => 'value',
      '#value' =>
      array (
      ),
    ),
  ),
  'og_initial_groups' =>
  array (
    '#type' => 'value',
    '#value' => NULL,
  ),
?>

Agaric's new friend, organic groups' save ancestry function:

<?php
function og_save_ancestry($node) {
  if (og_is_group_post_type($node->type)) {
    $sql = "DELETE FROM {og_ancestry} WHERE nid = %d";
    db_query($sql, $node->nid);
    if (is_array($node->og_groups)) {
      $node->og_groups = array_unique($node->og_groups);
      foreach ($node->og_groups as $gid) {
        $sql = "INSERT INTO {og_ancestry} (nid, group_nid, is_public) VALUES (%d, %d, %d)";
        db_query($sql, $node->nid, $gid, $node->og_public);
      }
    }
  }
}
?>

<?php
  'og_initial_groups' =>
  array (
    '#type' => 'value',
    '#value' =>
    array (
      0 => 11054,
    ),
  ),
  'og_nodeapi' =>
  array (
    'visible' =>
    array (
      'og_groups' =>
      array (
        '#type' => 'checkboxes',
        '#title' => 'Audience',
        '#attributes' =>
        array (
          'class' => 'og-audience',
        ),
        '#options' =>
        array (
          11054 => 'A Center for Development and Entrepreneurship',
        ),
        '#required' => false,
        '#description' => 'Show this post in this group.',
        '#default_value' =>
        array (
          0 => 11054,
        ),
        '#multiple' => true,
      ),
    ),
  ),
?>

Resolution