Revise the structure, layout, and visibility of your node fields

Submitted by Eric on Tue, 11/04/2008 - 11:16

When creating your theme, you may need absolute control over your node fields, and creating a node specific template file (CONTENTTYPE.tpl.php) does not give you enough flexibility. This code snippet defines a preprocess_node hook to modify the $content variable, so the field html has already been modified before it reaches your theme.

<?php
function MYMODULE_preprocess_node(&$variables) {
  // test for your node type that you'd like to modify
  if ($variables['type']=='MYNODETYPE') {
    // prepare your node object so the fields can be rendered individually
    $newNode = node_build_content(node_load($variables['nid']));

    // define a variable to hold your rendered content
    $newContent = "";

    // example: define a list of fields to show in an item list
    $itemListFields = array('field_itemlist_1','field_itemlist_2','field_itemlist_3');
    $itemListFieldsData = array();

    // loop through the node content
    foreach ($newNode->content as $k => $v) {
      // example: to prevent a field from being shown,
      // simply render the field and don't capture the output
      if ($k == 'MYFIELDTOHIDE') {
        drupal_render($v);
      } elseif (in_array($k, $itemListFields)) {
        // example: group some fields in an item list
        $itemListFieldsData[] = drupal_render($v);
      } elseif ($k == 'MYOTHERFIELD') {
        // example: surround a field in a div
        $newContent .= "<div id='MYHTMLID'>" . drupal_render($v) . "</div>";
      } else {
        // render the remaining fields and capture the output
        $newContent .= drupal_render($v);
      }

    }

    // example: generate the output for the item list
    if (count($itemListFieldsData)) $newContent .= theme('item_list', $itemListFieldsData);

    // replace the content variable
    if (strlen($newContent)) $variables['content'] = $newContent;

  }

}
?>

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Comments

Thanks! Addition to avoid WSOD

Submitted by Anonymous on Fri, 04/16/2010 - 21:48.

Extremely helpful post, thanks very much for sharing!

I was getting the following error when I first tried your code:

PHP Fatal error: Unsupported operand types in /drupal6/includes/common.inc on line 2845

It seems the problem was caused by passing the #pre_render and #content_extra_fields elements of the $newNode->content array into drupal_render. Testing for those at the beginning of the foreach loop and NOT passing them to drupal_render got things working.

This led me to a slight variation on your approach: I specify only the specific fields that need to be rendered individually. After each field is rendered (inside the foreach loop), I unset its element from the $newNode->content array. Then all the remaining fields can be rendered by throwing the entire (now smaller) $newNode->content into drupal_render (after the foreach loop is done).

That way if new fields are added to the content type later, they'll at least show up in $node->content.