DRUPAL*DRUPAL

<?php
// $Id: hiragana_captcha.module,v 1.0 2008/06/29 0829 Exp $

/**
 * Implementation of hook_menu().
 */
function hiragana_captcha_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/user/captcha/hiragana_captcha',
      'title' => t('Hiragana CAPTCHA'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('hiragana_captcha_settings_form'),
      'type' => MENU_LOCAL_TASK,
    );
  }
  return $items;
}

/**
 * Implementation of hook_help().
 */
function hiragana_captcha_help($section) {
  switch ($section) {
    case 'admin/user/captcha/hiragana_captcha':
      return '<p>'. t('The hiragana CAPTCHA ask for the n^th word of a predetermined phrase like text CAPTCHA.') .'</p>';
  }
}

/**
 * Administration form.
 */
function hiragana_captcha_settings_form() {
  $form = array();
  $form['hiragana_captcha_words'] = array(
    '#type' => 'fieldset',
    '#title' => t('Words settings'),
    '#description' => t('Input the generated word length and number of words in the phrase for hiragana CAPTCHA.'),
  );
  $form['hiragana_captcha_words']['hiragana_captcha_length_min'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum number of characters'),
    '#default_value' => variable_get('hiragana_captcha_length_min', 3),
    '#size' => 2,
    '#maxlength' => 2,
  );
  $form['hiragana_captcha_words']['hiragana_captcha_length_max'] = array(
    '#type' => 'textfield',
    '#title' => t('Maximum number of characters'),
    '#default_value' => variable_get('hiragana_captcha_length_max', 3),
    '#size' => 2,
    '#maxlength' => 2,
  );
  $form['hiragana_captcha_words']['hiragana_captcha_quantity'] = array(
    '#type' => 'textfield',
    '#title' => t('Number of words in the phrase'),
    '#default_value' => variable_get('hiragana_captcha_quantity', 5),
    '#size' => 2,
    '#maxlength' => 2,
  );
  return system_settings_form($form);
}

/**
 * Validate function of the administration form.
 */
function hiragana_captcha_settings_form_validate($form_id, $form_values) {
  if ($form_id == 'hiragana_captcha_settings_form') {
    if ($form_values['hiragana_captcha_length_min'] < 1 || $form_values['hiragana_captcha_length_max'] < 1) {
      form_set_error('hiragana_captcha_length', t('Minimum and maximum number of characters should be more than \'1\'.'));
    }
    else if ($form_values['hiragana_captcha_length_min'] > $form_values['hiragana_captcha_length_max']) {
      form_set_error('hiragana_captcha_length', t('Maximum number of characters should be more than minimum number of characters.'));
    }
    if ($form_values['hiragana_captcha_quantity'] < 4 || $form_values['hiragana_captcha_quantity'] > 10) {
      form_set_error('hiragana_captcha_quantity', t('Number of words in the phrase should be between 4 and 10.'));
    }
  }
}

/**
 * Implementation of hook_captcha().
 */
function hiragana_captcha_captcha($op, $captcha_type='') {
  switch ($op) {
    case 'list':
      return array('Hiragana');
    case 'generate':
      if ($captcha_type == 'Hiragana') {
        $words = _hiragana_captcha_generate_phrase(variable_get('hiragana_captcha_quantity', 5));
        $key = array_rand($words, 1);
        $answer = $words[$key];
        $result = array();
        $result['solution'] = $answer;
        $result['form']['captcha_response'] = array(
          '#type' => 'textfield',
          '#title' => t('What is the @nth word in the phrase "@words"?', array('@nth' => _hiragana_captcha_ordinal($key + 1), '@words' => implode(' / ', $words))),
          '#weight' => 0,
          '#size' => 15,
          '#required' => TRUE,
        );
        return $result;
      }
  }
}

/**
 * function for generating a random nonsense word of a given number of characters.
 */
function _hiragana_captcha_generate_word($min, $max) {
  $kana = "あいうえおかきくけこさしすせそたちつてとなにぬねのはひふへほまみむめもやゆよらりるれろわをん";
  $end = mb_strlen($kana) - 1;
  $length = mt_rand($min, $max);
  $word = '';
  for ($i = 0; $i < $length; ++$i) {
    $word .= mb_substr($kana, mt_rand(0, $end), 1);
  }
  return $word;
}

/**
 * function for generating an array of words.
 */
function _hiragana_captcha_generate_phrase($quantity) {
  $length = variable_get('hiragana_captcha_length_min', 3);
  $words = array();
  for ($w = 0; $w < $quantity; ++$w) {
    $words[] = _hiragana_captcha_generate_word(variable_get('hiragana_captcha_length_min', 3), variable_get('hiragana_captcha_length_max', 3));
  }
  return $words;
}

/**
 * function that returns a textual represention of an ordinal.
 */
function _hiragana_captcha_ordinal($n) {
  $ordinalmap = array(
    1 => t('first'),
    2 => t('second'),
    3 => t('third'),
    4 => t('fourth'),
    5 => t('fifth'),
    6 => t('sixth'),
    7 => t('seventh'),
    8 => t('eighth'),
    9 => t('ninth'),
    10 => t('tenth')
  );
  if (array_key_exists($n, $ordinalmap)) {
    return $ordinalmap[$n];
  }
  else {
    return "{$n}th";
  }
}

<?php
// $Id: hiragana_captcha.install,v 1.0 2008/06/29 0829 Exp $

/**
 * On uninstall: remove module variables and clear variable cache
 */
function hiragana_captcha_uninstall() {
  db_query("DELETE FROM {variable} WHERE name LIKE 'hiragana_captcha_%'");
  cache_clear_all('variables', 'cache');
}

<?php
// $Id: hiragana_captcha.user.inc,v 1.0 2008/06/29 0829 Exp $

/**
 * function for generating a random nonsense word of a given number of characters.
 */
function _hiragana_captcha_generate_word($min, $max) {
  $kana = "あいうえおかきくけこさしすせそたちつてとなにぬねのはひふへほまみむめもやゆよらりるれろわをん";
  $end = mb_strlen($kana) - 1;
  $length = mt_rand($min, $max);
  $word = '';
  for ($i = 0; $i < $length; ++$i) {
    $word .= mb_substr($kana, mt_rand(0, $end), 1);
  }
  return $word;
}

/**
 * function for generating an array of words.
 */
function _hiragana_captcha_generate_phrase($quantity) {
  $length = variable_get('hiragana_captcha_length_min', 3);
  $words = array();
  for ($w = 0; $w < $quantity; ++$w) {
    $words[] = _hiragana_captcha_generate_word(variable_get('hiragana_captcha_length_min', 3), variable_get('hiragana_captcha_length_max', 3));
  }
  return $words;
}

/**
 * function that returns a textual represention of an ordinal.
 */
function _hiragana_captcha_ordinal($n) {
  $ordinalmap = array(
    1 => t('first'),
    2 => t('second'),
    3 => t('third'),
    4 => t('fourth'),
    5 => t('fifth'),
    6 => t('sixth'),
    7 => t('seventh'),
    8 => t('eighth'),
    9 => t('ninth'),
    10 => t('tenth')
  );
  if (array_key_exists($n, $ordinalmap)) {
    return $ordinalmap[$n];
  }
  else {
    return "{$n}th";
  }
}