Remixing Drupal the Agaric Way: Multilingual Panels

Step 1: Find a function that does some or most of what you want.
Step 2: Find another function that does the rest of what you want.
Step 3: Mash them together.

The situation this time: we have a Drupal 5 site (World Social Forum 2008) with i18n (internationalization module) and need translated content to show up in panels.

Update: Go straight to the patch.

Here's some code in translation.module of the i18n package that shows one way this translation system for multilingual Drupal 5 figures out what nodes to care about:

<pre>
/**
* Implementation of hook_link().
*/
function translation_link($type, $node = NULL, $teaser = FALSE) {
  $languages = i18n_supported_languages();
  $links = array();
  if ($type == 'node' && variable_get('i18n_translation_node_links', 0) > ($teaser ? 1 : 0) && $node->translation) {
    foreach ($node->translation as $lang => $trnode) {
      // Add node link if published
      if($trnode->status) {
        // If language is not enabled, we'll use current language for the prefix
        $baselang = variable_get('i18n_translation_links', 0) || !isset($languages[$lang]) ? i18n_get_lang() : $lang;
        $links['translation-'.$lang]= theme('translation_node_link', $trnode , $lang, $baselang);
      }
    }
  }
  return $links;
}
</pre>

And here is the code from node.inc of the Panels package, which provides all the basic information for showing nodes:

<pre>/**
* Output function for the 'node' content type. Outputs a node
* based on the nid and settings supplied in the configuration.
*/
function panels_content_node($conf) {
  $node = node_load($conf['nid']);
  if (!node_access('view', $node)) {
    return;
  }

  if ($conf['suppress_title']) {
    $node->title = '';
  }

  $output = node_view($node, $conf['teaser'], FALSE, $conf['links']);
  return $output;
}</pre>

(Note: I've already changed the comment text above this function, which in the original was clearly a copy of the block.inc text.)

So let's mix and match, making the panels node view function multilingual-compatible with the parts Agaric added in bold:

<pre>
function panels_content_node($conf) {
  $node = node_load($conf['nid']);
  if (!node_access('view', $node)) {
    return;
  }
<strong>
  /* this could be optimized to check for translations by nid
   * BEFORE the node is loaded above.  This is a lot easier though.
   * Maybe not a big deal with node caching?
   */
  if ($node->translation) {
    // i18n_get_lang() gets the language the site is being browsed in
    if (array_key_exists(i18n_get_lang(), $node->translation)) {
      $lang = i18n_get_lang();
    } else {
      // use the default language
      $lang = i18n_default_language();
    }
    // avoid redundant node load, even if cached
    if ($node->language != $lang) { 
      $node = node_load($node->translation[$lang]->nid);
    }
  }
</strong>
  if ($conf['suppress_title']) {
    $node->title = '';
  }

  $output = node_view($node, $conf['teaser'], FALSE, $conf['links']);
  return $output;
}
</pre>

Agaric is pretty sure you aren't consigned to hell for hacking Drupal contrib modules. Only a few years in purgatory. This would have been better done with creating another include file to provide a separate interface for translated nodes, but this has very little performance impact if the node doesn't have a translation-- and Views 2 plus Drupal 6 had better just do it!

Resolution