drupal/modules/poll/poll.module

<?php
// $Id$

/**
 * @file
 * Enables your site to capture votes on different topics in the form of multiple
 * choice questions.
 */

/**
 * Implementation of hook_help().
 */
function poll_help($path, $arg) {
  switch ($path) {
    case 'admin/help#poll':
      $output = '<p>'. t('The poll module can be used to create simple polls for site users. A poll is a simple multiple choice questionnaire which displays the cumulative results of the answers to the poll. Having polls on the site is a good way to get instant feedback from community members.') .'</p>';
      $output .= '<p>'. t('Users can create a poll. The title of the poll should be the question, then enter the answers and the "base" vote counts. You can also choose the time period over which the vote will run.The <a href="@poll">poll</a> item in the navigation menu will take you to a page where you can see all the current polls, vote on them (if you haven\'t already) and view the results.', array('@poll' => url('poll'))) .'</p>';
      $output .= '<p>'. t('For more information please read the configuration and customization handbook <a href="@poll">Poll page</a>.', array('@poll' => 'http://drupal.org/handbook/modules/poll/')) .'</p>';
      return $output;
  }
}

/**
 * Implementation of hook_init().
 */
function poll_init() {
  drupal_add_css(drupal_get_path('module', 'poll') .'/poll.css');
}

/**
 * Implementation of hook_theme()
 */
function poll_theme() {
  return array(
    'poll_vote' => array(
      'file' => 'poll-vote',
      'arguments' => array('form' => NULL),
    ),
    'poll_results' => array(
      'file' => 'poll-results',
      'arguments' => array('raw_title' => NULL, 'results' => NULL, 'votes' => NULL, 'raw_links' => NULL, 'block' => NULL, 'nid' => NULL, 'vote' => NULL),
    ),
    'poll_bar' => array(
      'file' => 'poll-bar',
      'arguments' => array('title' => NULL, 'votes' => NULL, 'total_votes' => NULL, 'vote' => NULL, 'block' => NULL),
    ),
  );
}

/**
 * Implementation of hook_perm().
 */
function poll_perm() {
  return array('create polls', 'vote on polls', 'cancel own vote', 'inspect all votes');
}

/**
 * Implementation of hook_access().
 */
function poll_access($op, $node) {
  if ($op == 'create') {
    return user_access('create polls');
  }
}

/**
 * Implementation of hook_menu().
 */
function poll_menu() {
  $items['poll'] = array(
    'title' => 'Polls',
    'page callback' => 'poll_page',
    'access arguments' => array('access content'),
    'type' => MENU_SUGGESTED_ITEM,
  );

  $items['node/%node/votes'] = array(
    'title' => 'Votes',
    'page callback' => 'poll_votes',
    'page arguments' => array(1),
    'access callback' => '_poll_menu_access',
    'access arguments' => array(1, 'inspect all votes', FALSE),
    'weight' => 3,
    'type' => MENU_LOCAL_TASK,
  );

  $items['node/%node/results'] = array(
    'title' => 'Results',
    'page callback' => 'poll_results',
    'page arguments' => array(1),
    'access callback' => '_poll_menu_access',
    'access arguments' => array(1, 'access content', TRUE),
    'weight' => 3,
    'type' => MENU_LOCAL_TASK,
  );
  return $items;
}

/**
 * Callback function to see if a node is acceptable for poll menu items.
 */
function _poll_menu_access($node, $perm, $inspect_allowvotes) {
  return user_access($perm) && ($node->type == 'poll') && ($node->allowvotes || !$inspect_allowvotes);
}

/**
 * Implementation of hook_block().
 *
 * Generates a block containing the latest poll.
 */
function poll_block($op = 'list', $delta = 0) {
  if (user_access('access content')) {
    if ($op == 'list') {
      $blocks[0]['info'] = t('Most recent poll');
      return $blocks;
    }
    else if ($op == 'view') {
      // Retrieve the latest poll.
      $sql = db_rewrite_sql("SELECT MAX(n.created) FROM {node} n INNER JOIN {poll} p ON p.nid = n.nid WHERE n.status = 1 AND p.active = 1");
      $timestamp = db_result(db_query($sql));
      if ($timestamp) {
        $poll = node_load(array('type' => 'poll', 'created' => $timestamp, 'status' => 1));

        if ($poll->nid) {
          $poll = poll_view($poll, TRUE, FALSE, TRUE);
        }
      }
      $block['subject'] = t('Poll');
      $block['content'] = drupal_render($poll->content);
      return $block;
    }
  }
}

/**
 * Implementation of hook_cron().
 *
 * Closes polls that have exceeded their allowed runtime.
 */
function poll_cron() {
  $result = db_query('SELECT p.nid FROM {poll} p INNER JOIN {node} n ON p.nid = n.nid WHERE (n.created + p.runtime) < '. time() .' AND p.active = 1 AND p.runtime != 0');
  while ($poll = db_fetch_object($result)) {
    db_query("UPDATE {poll} SET active = 0 WHERE nid = %d", $poll->nid);
  }
}

/**
 * Implementation of hook_node_info().
 */
function poll_node_info() {
  return array(
    'poll' => array(
      'name' => t('Poll'),
      'module' => 'poll',
      'description' => t("A poll is a multiple-choice question which visitors can vote on."),
      'title_label' => t('Question'),
      'has_body' => FALSE,
    )
  );
}

/**
 * Implementation of hook_form().
 */
function poll_form(&$node, $form_state) {
  $admin = user_access('administer nodes');
  $type = node_get_types('type', $node);
  $form['title'] = array(
    '#type' => 'textfield',
    '#title' => check_plain($type->title_label),
    '#required' => TRUE,
    '#default_value' => $node->title,
    '#weight' => -1
  );

  if (isset($form_state['choices'])) {
    $choices = $form_state['choices'];
  }
  else {
    $choices = max(2, empty($node->choice) ? 5 : count($node->choice));
  }

  $form['choices'] = array(
    '#type' => 'hidden',
    '#value' => $choices,
  );

  // Poll choices
  $form['choice'] = array(
    '#type' => 'fieldset',
    '#title' => t('Choices'),
    '#prefix' => '<div class="poll-form">',
    '#suffix' => '</div>',
    '#tree' => TRUE
  );

  // We'll manually set the #parents property of this checkbox so that
  // it appears in the fieldset visually, but its value won't pollute
  // the $form_state['values']['choice'] array.
  $form['choice']['morechoices'] = array(
    '#type' => 'checkbox',
    '#parents' => array('morechoices'),
    '#title' => t('Need more choices'),
    '#default_value' => 0,
    '#description' => t("If the amount of boxes above isn't enough, check this box and click the Preview button below to add some more."),
    '#weight' => 1,
  );

  for ($a = 0; $a < $choices; $a++) {
    $form['choice'][$a]['chtext'] = array(
      '#type' => 'textfield',
      '#title' => t('Choice @n', array('@n' => ($a + 1))),
      '#default_value' => isset($node->choice[$a]) ? $node->choice[$a]['chtext'] : '',
    );

    if ($admin) {
      $form['choice'][$a]['chvotes'] = array(
        '#type' => 'textfield',
        '#title' => t('Votes for choice @n', array('@n' => ($a + 1))),
        '#default_value' => isset($node->choice[$a]) ? (int)$node->choice[$a]['chvotes'] : 0,
        '#size' => 5, '#maxlength' => 7
      );
    }
  }

  // Poll attributes
  $_duration = array(0 => t('Unlimited')) + drupal_map_assoc(array(86400, 172800, 345600, 604800, 1209600, 2419200, 4838400, 9676800, 31536000), "format_interval");
  $_active = array(0 => t('Closed'), 1 => t('Active'));

  if ($admin) {
    $form['settings'] = array('#type' => 'fieldset', '#title' => t('Settings'));

    $form['settings']['active'] = array(
      '#type' => 'radios',
      '#title' => t('Poll status'),
      '#default_value' => isset($node->active) ? $node->active : 1,
      '#options' => $_active,
      '#description' => t('When a poll is closed, visitors can no longer vote for it.')
    );
  }
  $form['settings']['runtime'] = array(
    '#type' => 'select',
    '#title' => t('Poll duration'),
    '#default_value' => isset($node->runtime) ? $node->runtime : 0,
    '#options' => $_duration,
    '#description' => t('After this period, the poll will be closed automatically.'),
  );

  return $form;
}

/**
 * Implementation of hook_submit().
 */
function poll_node_form_submit(&$form, &$form_state) {
  // Renumber fields
  $form_state['values']['choice'] = array_values($form_state['values']['choice']);
  $form_state['values']['teaser'] = poll_teaser((object)$form_state['values']);
  $form_state['choices'] = $form_state['values']['choices'];
  if ($form_state['values']['morechoices']) {
    $form_state['choices'] *= 2;
  }
}

/**
 * Implementation of hook_validate().
 */
function poll_validate($node) {
  if (isset($node->title)) {
    // Check for at least two options and validate amount of votes:
    $realchoices = 0;
    // Renumber fields
    $node->choice = array_values($node->choice);
    foreach ($node->choice as $i => $choice) {
      if ($choice['chtext'] != '') {
        $realchoices++;
      }
      if ($choice['chvotes'] < 0) {
        form_set_error("choice][$i][chvotes", t('Negative values are not allowed.'));
      }
    }

    if ($realchoices < 2) {
      form_set_error("choice][$realchoices][chtext", t('You must fill in at least two choices.'));
    }
  }
}

/**
 * Implementation of hook_load().
 */
function poll_load($node) {
  global $user;

  // Load the appropriate choices into the $node object
  $poll = db_fetch_object(db_query("SELECT runtime, active FROM {poll} WHERE nid = %d", $node->nid));

  $result = db_query("SELECT chtext, chvotes, chorder FROM {poll_choices} WHERE nid = %d ORDER BY chorder", $node->nid);
  while ($choice = db_fetch_array($result)) {
    $poll->choice[$choice['chorder']] = $choice;
  }

  // Determine whether or not this user is allowed to vote
  $poll->allowvotes = FALSE;
  if (user_access('vote on polls') && $poll->active) {
    if ($user->uid) {
      $result = db_fetch_object(db_query('SELECT chorder FROM {poll_votes} WHERE nid = %d AND uid = %d', $node->nid, $user->uid));
    }
    else {
      $result = db_fetch_object(db_query("SELECT chorder FROM {poll_votes} WHERE nid = %d AND hostname = '%s'", $node->nid, ip_address()));
    }
    if (isset($result->chorder)) {
      $poll->vote = $result->chorder;
    }
    else {
      $poll->vote = -1;
      $poll->allowvotes = TRUE;
    }
  }
  return $poll;
}

/**
 * Implementation of hook_insert().
 */
function poll_insert($node) {
  if (!user_access('administer nodes')) {
    // Make sure all votes are 0 initially
    foreach ($node->choice as $i => $choice) {
      $node->choice[$i]['chvotes'] = 0;
    }
    $node->active = 1;
  }

  db_query("INSERT INTO {poll} (nid, runtime, active) VALUES (%d, %d, %d)", $node->nid, $node->runtime, $node->active);

  $i = 0;
  foreach ($node->choice as $choice) {
    if ($choice['chtext'] != '') {
      db_query("INSERT INTO {poll_choices} (nid, chtext, chvotes, chorder) VALUES (%d, '%s', %d, %d)", $node->nid, $choice['chtext'], $choice['chvotes'], $i++);
    }
  }
}

/**
 * Implementation of hook_update().
 */
function poll_update($node) {
  db_query('UPDATE {poll} SET runtime = %d, active = %d WHERE nid = %d', $node->runtime, $node->active, $node->nid);

  db_query('DELETE FROM {poll_choices} WHERE nid = %d', $node->nid);
  db_query('DELETE FROM {poll_votes} WHERE nid = %d', $node->nid);

  $i = 0;
  foreach ($node->choice as $choice) {
    $chvotes = (int)$choice['chvotes'];
    $chtext = $choice['chtext'];

    if ($chtext != '') {
      db_query("INSERT INTO {poll_choices} (nid, chtext, chvotes, chorder) VALUES (%d, '%s', %d, %d)", $node->nid, $chtext, $chvotes, $i++);
    }
  }
}

/**
 * Implementation of hook_delete().
 */
function poll_delete($node) {
  db_query("DELETE FROM {poll} WHERE nid = %d", $node->nid);
  db_query("DELETE FROM {poll_choices} WHERE nid = %d", $node->nid);
  db_query("DELETE FROM {poll_votes} WHERE nid = %d", $node->nid);
}

/**
 * Implementation of hook_view().
 *
 * @param $block
 *   An extra parameter that adapts the hook to display a block-ready
 *   rendering of the poll.
 */
function poll_view($node, $teaser = FALSE, $page = FALSE, $block = FALSE) {
  global $user;
  $output = '';

  // Special display for side-block
  if ($block) {
    // No 'read more' link
    $node->readmore = FALSE;

    $links = module_invoke_all('link', 'node', $node, 1);
    $links[] = array('title' => t('Older polls'), 'href' => 'poll', 'attributes' => array('title' => t('View the list of polls on this site.')));
    if ($node->allowvotes && $block) {
      $links[] = array('title' => t('Results'), 'href' => 'node/'. $node->nid .'/results', 'attributes' => array('title' => t('View the current poll results.')));
    }

    $node->links = $links;
  }

  if (!empty($node->allowvotes) && ($block || empty($node->show_results))) {
    $node->content['body'] = array(
      '#value' => drupal_get_form('poll_view_voting', $node, $block),
    );
  }
  else {
    $node->content['body'] = array(
      '#value' => poll_view_results($node, $teaser, $page, $block),
    );
  }
  return $node;
}

/**
 * Menu callback to provide a simple list of all polls available.
 */
function poll_page() {
  // List all polls
  $sql = "SELECT n.nid, n.title, p.active, n.created, SUM(c.chvotes) AS votes FROM {node} n INNER JOIN {poll} p ON n.nid = p.nid INNER JOIN {poll_choices} c ON n.nid = c.nid WHERE n.status = 1 GROUP BY n.nid, n.title, p.active, n.created ORDER BY n.created DESC";
  $sql = db_rewrite_sql($sql);
  $result = pager_query($sql, 15);
  $output = '<ul>';
  while ($node = db_fetch_object($result)) {
    $output .= '<li>'. l($node->title, "node/$node->nid") .' - '. format_plural($node->votes, '1 vote', '@count votes') .' - '. ($node->active ? t('open') : t('closed')) .'</li>';
  }
  $output .= '</ul>';
  $output .= theme("pager", NULL, 15);
  return $output;
}

/**
 * Creates a simple teaser that lists all the choices. 
 *
 * This is primarily used for RSS.
 */
function poll_teaser($node) {
  $teaser = NULL;
  if (is_array($node->choice)) {
    foreach ($node->choice as $k => $choice) {
      $teaser .= '* '. $choice['chtext'] .'\n';
    }
  }
  return $teaser;
}

/**
 * Generates the voting form for a poll.
 *
 * @ingroup forms
 * @see poll_vote()
 * @see phptemplate_preprocess_poll_vote()
 */
function poll_view_voting(&$form_state, $node, $block) {
  if ($node->choice) {
    $list = array();
    foreach ($node->choice as $i => $choice) {
      $list[$i] = check_plain($choice['chtext']);
    }
    $form['choice'] = array(
      '#type' => 'radios',
      '#default_value' => -1,
      '#options' => $list,
    );
  }
  
  $form['vote'] = array(
    '#type' => 'submit', 
    '#value' => t('Vote'),
    '#submit' => array('poll_vote'),
  );

  // Store the node so we can get to it in submit functions.
  $form['#node'] = $node;
  $form['#block'] = $block;

  // Set form caching because we could have multiple of these forms on
  // the same page, and we want to ensure the right one gets picked.
  $form['#cache'] = TRUE;

  // Provide a more cleanly named voting form theme.
  $form['#theme'] = 'poll_vote';
  return $form;
}

/**
 * Submit handler for processing a vote
 */
function poll_vote($form, &$form_state) {
  $node = $form['#node'];
  $choice = $form_state['values']['choice'];

  global $user;
  if ($user->uid) {
    db_query('INSERT INTO {poll_votes} (nid, chorder, uid) VALUES (%d, %d, %d)', $node->nid, $choice, $user->uid);
  }
  else {
    db_query("INSERT INTO {poll_votes} (nid, chorder, hostname) VALUES (%d, %d, '%s')", $node->nid, $choice, ip_address());
  }

  // Add one to the votes.
  db_query("UPDATE {poll_choices} SET chvotes = chvotes + 1 WHERE nid = %d AND chorder = %d", $node->nid, $choice);

  cache_clear_all();
  drupal_set_message(t('Your vote was recorded.'));

  // Return the user to whatever page they voted from.
}

/**
 * Themes the voting form for a poll.
 *
 * Inputs: $form
 */
function template_preprocess_poll_vote(&$variables) {
  $form = $variables['form'];
  $variables['choice'] = drupal_render($form['choice']);
  $variables['title'] = check_plain($form['#node']->title);
  $variables['vote'] = drupal_render($form['vote']);
  $variables['rest'] = drupal_render($form);
  $variables['block'] = $form['#block'];
}

/**
 * Generates a graphical representation of the results of a poll.
 */
function poll_view_results(&$node, $teaser, $page, $block) {
  // Count the votes and find the maximum
  $total_votes = 0;
  $max_votes = 0;
  foreach ($node->choice as $choice) {
    $total_votes += $choice['chvotes'];
    $max_votes = max($max_votes, $choice['chvotes']);
  }

  $poll_results = '';
  foreach ($node->choice as $i => $choice) {
    if ($choice['chtext'] != '') {
      $poll_results .= theme('poll_bar', $choice['chtext'], $choice['chvotes'], $total_votes, isset($node->vote) && $node->vote == $i, $block);
    }
  }

  return theme('poll_results', $node->title, $poll_results, $total_votes, isset($node->links) ? $node->links : array(), $block, $node->nid, isset($node->vote) ? $node->vote : NULL);
}

/**
 * Preprocess the poll_results theme hook.
 *
 * Inputs: $raw_title, $results, $votes, $raw_links, $block, $nid, $vote. The
 * $raw_* inputs to this are naturally unsafe; often safe versions are
 * made to simply overwrite the raw version, but in this case it seems likely
 * that the title and the links may be overridden by the theme layer, so they
 * are left in with a different name for that purpose.
 *
 * @see poll-results.tpl.php
 * @see poll-results-block.tpl.php
 * @see theme_poll_results()
 */
function template_preprocess_poll_results(&$variables) {
  $variables['links'] = theme('links', $variables['raw_links']);
  if (isset($variables['vote']) && $variables['vote'] > -1 && user_access('cancel own vote')) {
    $variables['cancel_form'] = drupal_get_form('poll_cancel_form', $variables['nid']);
  }
  $variables['title'] = check_plain($variables['raw_title']);

  // If this is a block, allow a different tpl.php to be used.
  if ($variables['block']) {
    $variables['template_files'][] = 'poll-results-block';
  }
}

/**
 * Preprocess the poll_bar theme hook.
 *
 * Inputs: $title, $votes, $total_votes, $voted, $block
 *
 * @see poll-bar.tpl.php
 * @see poll-bar-block.tpl.php
 * @see theme_poll_bar()
 */
function template_preprocess_poll_bar(&$variables) {
  if ($variables['block']) {
    $variables['template_files'][] = 'poll-bar-block';
  }
  $variables['title'] = check_plain($variables['title']);
  $variables['percentage'] = round($variables['votes'] * 100 / max($variables['total_votes'], 1));
}

/**
 * Builds the cancel form for a poll.
 *
 * @ingroup forms
 * @see poll_cancel()
 */
function poll_cancel_form(&$form_state, $nid) {
  // Store the nid so we can get to it in submit functions.
  $form['#nid'] = $nid;

  $form['submit'] = array(
    '#type' => 'submit', 
    '#value' => t('Cancel your vote'),
    '#submit' => array('poll_cancel')
  );

  $form['#cache'] = TRUE;

  return $form;
}

/**
 * Submit callback for poll_cancel_form
 */
function poll_cancel($form, &$form_state) {
  $node = node_load($form['#nid']);
  global $user;

  if ($user->uid) {
    db_query('DELETE FROM {poll_votes} WHERE nid = %d and uid = %d', $node->nid, $user->uid);
  }
  else {
    db_query("DELETE FROM {poll_votes} WHERE nid = %d and hostname = '%s'", $node->nid, ip_address());
  }

  // Subtract from the votes.
  db_query("UPDATE {poll_choices} SET chvotes = chvotes - 1 WHERE nid = %d AND chorder = %d", $node->nid, $node->vote);
}

/**
 * Callback for the 'results' tab for polls you can vote on
 */
function poll_results($node) {
  drupal_set_title(check_plain($node->title));
  $node->show_results = TRUE;
  return node_show($node, 0);
}

/**
 * Callback for the 'votes' tab for polls you can see other votes on
 */
function poll_votes($node) {
  drupal_set_title(check_plain($node->title));
  $output = t('This table lists all the recorded votes for this poll.  If anonymous users are allowed to vote, they will be identified by the IP address of the computer they used when they voted.');

  $header[] = array('data' => t('Visitor'), 'field' => 'u.name');
  $header[] = array('data' => t('Vote'), 'field' => 'pv.chorder');

  $result = pager_query("SELECT pv.chorder, pv.uid, pv.hostname, u.name FROM {poll_votes} pv LEFT JOIN {users} u ON pv.uid = u.uid WHERE pv.nid = %d" . tablesort_sql($header), 20, 0, NULL, $node->nid);
  $rows = array();
  while ($vote = db_fetch_object($result)) {
    $rows[] = array(
      $vote->name ? theme('username', $vote) : check_plain($vote->hostname),
      check_plain($node->choice[$vote->chorder]['chtext']));
  }
  $output .= theme('table', $header, $rows);
  $output .= theme('pager', NULL, 20, 0);
  return $output;
}

/**
 * Implementation of hook_user().
 */
function poll_user($op, &$edit, &$user) {
  if ($op == 'delete') {
    db_query('UPDATE {poll_votes} SET uid = 0 WHERE uid = %d', $user->uid);
  }
}