Drupal form menu

Question

I have a menu callback, and I want to add a form on it using the following code.

function parking_calculator_menu() {
  $items['admin/parkingcalculator'] = array(
    'title' => 'Node parkingCalculator',
    'description' => 'Adjust node parkingCalculator options.',
    'position' => 'right',
    'weight' => -5,
    'page callback' => 'get_form',
    'access arguments' => array('administer site configuration'),
  );

  return $items;
}

function get_form() {
  $form['short-term-parking'] = array(
    '#title' => t('Short term parking'),
    '#type' => 'fieldset',
    '#description' => t('Short term parking.'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );

  $form['short-term-parking']['free_time'] = array(
    '#type' => 'textfield',
    '#required' => TRUE, 
    '#title' => t('Free time'),
    '#default_value' => variable_get('free_time', 1),
    '#description' => t('Please enter Free time.')
  );

  $form['short-term-parking']['long-term-starts'] = array(
    '#title' => t('Long term starts'),
    '#type' => 'textfield',
    '#default_value' => variable_get('long-term-starts', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter Long term starts.')
  );

  $form['short-term-parking']['first-hour-cost'] = array(
    '#title' => t('First hour cost'),
    '#type' => 'textfield',
    '#default_value' => variable_get('first-hour-cost', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter First hour cost.')
  );

  $form['short-term-parking']['each-hour-cost'] = array(
    '#title' => t('Each hour cost'),
    '#type' => 'textfield',
    '#default_value' => variable_get('each-hour-cost', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter Each hour cost.')
  );

  $form['long-term-parking'] = array(
    '#title' => t('Long term parking'),
    '#type' => 'fieldset',
    '#description' => t('Long term parking.'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE
  );

  $form['long-term-parking']['free_timel'] = array(
    '#type' => 'textfield',
    '#required' => TRUE, 
    '#default_value' => variable_get('free_timel', 1),
    '#title' => t('Free time'),
    '#description' => t('Please enter Free time.')
  );

  $form['long-term-parking']['long-term-startsl'] = array(
    '#title' => t('Long term starts'),
    '#default_value' => variable_get('long-term-startsl', 1),   
    '#type' => 'textfield',
    '#required' => TRUE, 
    '#description' => t('Please enter Long term starts.')
  );

  $form['long-term-parking']['first-hour-costl'] = array(
    '#title' => t('First hour cost'),
    '#type' => 'textfield',
    '#default_value' => variable_get('first-hour-costl', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter First hour cost.')
  );

  $form['long-term-parking']['each-hour-costl'] = array(
    '#title' => t('Each hour cost'),
    '#type' => 'textfield',
    '#default_value' => variable_get('each-hour-costl', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter Each hour cost.')
  );

  $form['valet-parking'] = array(
    '#title' => t('Valet parking'),
    '#type' => 'fieldset',
    '#description' => t('Valet parking.'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE
  );

  $form['valet-parking']['first-hour-costv'] = array(
    '#title' => t('First hour cost'),
    '#type' => 'textfield',
    '#default_value' => variable_get('first-hour-costv', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter First hour cost.')
  );

  $form['valet-parking']['each-hour-costv'] = array(
    '#title' => t('Each hour cost'),
    '#type' => 'textfield',
    '#default_value' => variable_get('each-hour-costv', 1),
    '#required' => TRUE, 
    '#description' => t('Please enter Each hour cost.')
  );

  return system_settings_form($form);
}

With this code, I get the following error message:

Recoverable fatal error: Argument 1 passed to drupal_attributes() must be an array, null given, called in /var/www/html/APIG01JO2012039/includes/form.inc on line 3252 and defined in drupal_attributes() (line 2366 of /var/www/html/APIG01JO2012039/includes/common.inc). The website encountered an unexpected error. Please try again later.

Why am I getting that error?

Answer 1

The page arguments hook_menu() expects is an array, not a string.

function parking_calculator_menu() {
  $items['admin/parkingcalculator'] = array(
    'title' => 'Node parkingCalculator',
    'description' => 'Adjust node parkingCalculator options.',
    'position' => 'right',
    'weight' => -5,
    'page callback' => 'drupal_get_form',
    // You used:
    // 'page callback' => 'get_form',
    // The correct value is the following one:
    'page arguments' => array('get_form'),
    'access arguments' => array('administer site configuration'),
  );

  return $items;
}