Setting Drupal Free Tags Programmatically

Overview

The following demonstrates a means to add taxonomy terms programmatically in Drupal 7 using a free tagging type of arrangement.

Problem

1. In this scenario we are using an external script (not shown here) to add new nodes to a Drupal 7 website programmatically.

2. We want to associate any number of terms in the vocabulary food to each node using a Term reference field having the machine name field_food.

3. We want to be able to create new terms in the food vocabulary on the fly.

4. We want all terms in the food vocabulary to be unique.

Solution

// This demonstrates how to get the vid by way of the
// vocabulary's machine name.
$vocab_machine_name = 'food';
$vocab = taxonomy_vocabulary_machine_name_load($vocab_machine_name);
// $vid = $vocab->vid;

// Add Taxonomy Terms Using Free Tagging

// These variables must be set, but you shouldn't 
// have to change aynthing in the foreach loop.
$node->language = LANGUAGE_NONE;
$field_name = 'field_food';
$vid = $vocab->vid;
$terms = array('apple', 'pear', 'avocodo', 'spinach');



foreach ($terms as $term) {
  $vterms = taxonomy_get_term_by_name($term);  
  // taxonomy_get_term_by_name() doesn't filter by vid, nor does it 
  // insure that a term name is unique in a given vocabulary. This means
  // we have to jump through some hoops. We only want unique term names, and
  // we want it to come from a specific vocabulary, so we're going to loop
  // through all the results and stop when we find a match.
  foreach ($vterms as $vterm) {
    if ($vterm->vid == $vid) {
      break;
    }
    unset($vterm);
  }
  // If this term doesn't yet exist, we must first create it 
  // so the tid can be referenced.  
  if (!$vterm) {
    $vterm = array(
      'vid' => $vid,
      'name' => $term
    );
    $vterm = (object) $vterm;
    taxonomy_term_save($vterm);
  }
  // Set the term.  
  $node->{$field_name}[$node->language][]['tid'] = $vterm->tid;
  unset($vterm);
}