get vocabulary id by name

Question

I can retrieve a vocabulary id directly from DB, but is there a built in function for this?

for example:

i have a vocabulary called "listing", i need that built in function takes "listing" as function argument, and return a vid.

i am using drupal 6

Answer 1

There is no built in function for this, afaik. You can roll your own by calling taxonomy_get_vocabularies() and search for your name in the resulting array, but this will do a database request on every call.

If you have a vocabulary that you often use from code, it might be easier/more effective to store the vid in a Drupal variable via variable_set() once and get it back via variable_get() (Many modules that create a vocabulary on install do it this way).

Edit: here is some sample code to do this on module install.

function mymodule_install() {
  $ret = array();
  $vocabulary = array(
      'name' => t('myvocab'),
      'multiple' => '1',
      'required' => '0',
      'hierarchy' => '1',
      'relations' => '0',
      'module' => 'mymodule',
      'nodes' => array('article' => 1), 
    );
  taxonomy_save_vocabulary($vocabulary);
  $vid = $vocabulary['vid'];
  variable_set('mymodule_myvocab', $vid);
  return $ret
 }

Answer 2

I have a function for this, well almost..

 /**
 * This function will return a vocabulary object which matches the
 * given name. Will return null if no such vocabulary exists.
 *
 * @param String $vocabulary_name
 *   This is the name of the section which is required
 * @return Object
 *   This is the vocabulary object with the name
 *   or null if no such vocabulary exists
 */
function mymodule_get_vocabulary_by_name($vocabulary_name) {
  $vocabs = taxonomy_get_vocabularies(NULL);
  foreach ($vocabs as $vocab_object) {
    if ($vocab_object->name == $vocabulary_name) {
      return $vocab_object;
    }
  }
  return NULL;
}

If you want the vid just get the vid property of the returned object and.

$vocab_object = mymodule_get_vocabulary_by_name("listing");
$my_vid = $vocab_object->vid;

Henriks point about storing it in a variable is very valid as the above code you won't want to be running on every request.