how to save new value of autocomplete field with hook_form_submit?

Question

creating a custom submit function for the form of mymodule

/**
 * Implements hook_form_submit()
 */
function mymodule_form_submit($form, &$form_state){

    $new_user = drupal_anonymous_user();
    // removed basic user fields here to make it more clear

    // save taxonomy checkbox field
    foreach ($form_state['values']['third']['field_functioncat'] as $key => $value) {
        if($value > 0){
            $new_user->field_functioncat[LANGUAGE_NONE][$key]['tid'] = $value;
        }
    }

    // save text field
    $new_user->field_firstname[LANGUAGE_NONE][0]['value'] = $form_state['values']['first']['field_firstname'];

    user_save($new_user); 
}

Above code works but I'm having trouble saving the autocomplete field.

What I'm trying:

// get value of the form
$tid = taxonomy_get_term_by_name($form_state['values']['first']['field_city'], 'field_city');
// get the first array value and then the tid of the left over object:
$tid = reset($tid)->tid;
// save field to user profile
$new_user->field_city[LANGUAGE_NONE][$tid]['tid'] = $tid;

This works for existing terms, but when I put in a new term it can't get the id of the term because that term name is not created?

How do I create the term name and get the tid to submit it to the user creation?

note: I've created the field_city as taxonomy term and linked it to the user profile so it's visible and editable in on the user edit profile page.

Answer 1

As you said if you're unable to find the tid then its a new term. You can save the new term using taxonomy_term_save()

For example,

$term = new stdClass();
$term->vid = <field city vid>;
$term->name = $form_state['values']['first']['field_city'];
taxonomy_term_save($term);

After saving the new term you can access the tid like this,

$term->tid

If you want to fetch the vid referenced with particular field then look at the following thread - How to get the field settings in drupal 7