Drupal 7 forms API: File upload

Question

I've been following the form example 10 from the Drupal doc: http://api.drupal.org/api/examples/form_example!form_example.module/group/form_example/7

Here goes the definition of my form:

function portal_upload_form($form, $form_state) {

    $form['file'] = array(
        '#type' => 'file',
        '#title' => t('Choose a file'),
    );

    $form['document_submit_button'] = array(

      '#type' => 'submit', 
      '#value' => t('upload'), 
    );

    return $form;
}

And the form_submit hook:

function portal_upload_form_submit($form, &$form_state) {

    $file = $form_state['values']['file'];
        // ...

$file is 'empty' despite having set an input file with 777 permissions. I'm missing something and can't find what on my own...

Thanks! J.

Solution 1

Doesn't answer the question of why the form doesn't provide with a file/url/... but it solves the whole upload issue:

function portal_upload_form_submit($form, &$form_state) {

    $file = $form_state['values']['file'];

    $validators = array();
    $file = file_save_upload('file', $validators, 'public://');

Solution 2

Here are a few other things to consider here:

1. file_save_upload() only will validate a default list of content types: jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp

2. Be sure to name your first item in an associative array format i.e. '#name' => 'files[img_1]',

file_save_upload() documentation, see the first comment for information on my second point.