gistfile1.php

  // For H10 style relations, we need to 'guesse' what the relation type is by examining the two endpoints
  function getRelationType($relation, $atominstance) {
    if ($relation['type'] != 'related') {
      return $relation['type'];
    }
    $otherinstance = highwire_get_raw_data($relation['apath']);

    if ($otherinstance['type'] != 'article') {
      return 'related';
    }
    // If the two article-types are different, we can likely examine their types to determine the relationships
    if ($otherinstance['article-type'] != $atominstance['article-type'])) {
      if ($otherinstance['article-type'] == 'correction') return 'Revision#correction';
      if ($otherinstance['article-type'] == 'letter')     return 'Revision#correction';
      if ($otherinstance['article-type'] == 'retraction') return 'Revision#retraction';
      if ($otherinstance['article-type'] == 'addendum')   return 'Revision#addendum';

      if ($atominstance['article-type'] == 'correction')  return 'Revision#subject';
      if ($atominstance['article-type'] == 'retraction')  return 'Revision#subject';
      if ($atominstance['article-type'] == 'letter')      return 'Revision#subject';
      if ($atominstance['article-type'] == 'addendum')    return 'Revision#subject';
    }

    if (!isset($relation['prop']) { // If we don't have an hwp:property element, we have no way of knowing...
      return 'related';
    }

    // Okay, let's look at the prop to see if we can scry the answer
    if (strcontains('rev_errata.atom',     $relation['prop'])) return 'Revision#subject';
    if (strcontains('rev_correction.atom', $relation['prop'])) return 'Revision#correction';
    if (strcontains('rev_retraction.atom', $relation['prop'])) return 'Revision#retraction';

    if (strcontains('errata.atom',     $relation['prop'])) return 'Revision#subject';
    if (strcontains('correction.atom', $relation['prop'])) return 'Revision#subject';
    if (strcontains('retraction.atom', $relation['prop'])) return 'Revision#subject';

    // Who knows?!?!
    return 'related';
  }