drupal/modules/poll.module

<?php
// $Id$

function poll_allowvotes(&$node) {
  /*
  ** Only accept votes on specific cases to prevent double voting and abuse.
  ** We only need to determine this once for a poll, but we don't do this in
  ** poll_load() (i.e. for every poll that is loaded) for speed reasons.
  */
  global $REMOTE_ADDR, $user;

  if ($node->allowvotes != -1) {
    return $node;
  }

  $node->allowvotes = 0;
  if (user_access("vote on polls")) {
    if ($user->uid) {
      // Pad the UID with underscores to allow a simple strstr() search
      $id = "_". $user->uid ."_";
    }
    else {
      $id = $REMOTE_ADDR;
    }
    if (!strstr($node->voters, $id)) {
      $node->allowvotes = $node->active;
    }

    // Save this for later
    $node->polluserid = $id;
  }
  return $node;
}

function poll_access($op, $node) {
  if ($op == "view") {
    return $node->status;
  }

  if ($op == "create") {
    return 1;
  }
}

function poll_block() {
  $timestamp = db_result(db_query("SELECT MAX(created) FROM node WHERE type='poll' AND status='1' AND moderate='0'"));
  if ($timestamp) {
    $poll = node_load(array("type" => "poll", "created" => $timestamp, "moderate" => "0", "status" => "1"));
    if ($poll->nid) {
      // Poll_view dumps the output into $poll->body
      poll_view($poll, 1, 1);
    }
  }
  $blocks[0][subject] = t("Latest poll: %t", array("%t" => $poll->title));
  $blocks[0][content] = $poll->body;
  $blocks[0][info] = t("Most recent poll");
  return $blocks;
}

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

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);
}

function poll_form(&$node, &$help, &$error) {
  $admin = user_access("administer nodes");

  $_duration = array(0 => t("Unlimited"), 86400 => format_interval(86400), 172800 => format_interval(172800), 345600 => format_interval(345600), 604800 => format_interval(604800), 1209600 => format_interval(1209600), 2419200 => format_interval(2419200), 4838400 => format_interval(4838400), 9676800 => format_interval(9676800), 31536000 => format_interval(31536000));
  $_active = array(0 => t("Closed"), 1 => t("Active"));

  $node->choices = $node->choices ? $node->choices : max(2, count($node->choice) ? count($node->choice) : 5);

  if (isset($node->title)) {
    // Check for at least two options and validate amount of votes:
    for ($i = 0; $i < $node->choices; $i++) {
      if ($node->choice[$i] != "") {
        $actualchoices++;
      }

      if ($node->chvotes[$i] < 0) {
        $error["chvotes][$i"] = theme_invoke("theme_error", t("Negative values are not allowed."));
      }
    }

    if ($actualchoices < 2) {
      $error["choice][0"] = theme_invoke("theme_error", t("You must fill in at least two choices."));
    }
  }
  else {
    $help = variable_get("poll_help", "");
  }

  if (function_exists("taxonomy_node_form")) {
    $output = implode("", taxonomy_node_form("poll", $node));
  }

  for ($c = 2; $c <= 30; $c++) {
    $opts[$c] = $c;
  }
  $output .= form_select(t("Number of choices"), "choices", $node->choices, $opts, t("This item sets the number of multiple choice options in the poll, but it doesn't have to equal the actual amount of options; you can leave the extra boxes empty."));
  $output .= form_submit(t("Preview")) ."<br /><br /><br />";

  for ($a = 0; $a < $node->choices; $a++) {
    $output .= form_textfield(t("Choice") ." ". ($a + 1), "choice][$a", $node->choice[$a], 50, 127, $error["choice][$a"]);
    if ($admin) {
      $output .= form_textfield(t("Votes for choice %n", array("%n" => ($a + 1))), "chvotes][$a", $node->chvotes[$a] ? $node->chvotes[$a] : 0, 7, 7, $error["chvotes][$a"]);
    }
  }

  if ($admin) {
    $output .= form_select(t("Poll status"), "active", isset($node->active) ? $node->active : 1, $_active);
  }

  $output .= form_select(t("Poll duration"), "runtime", $node->runtime ? $node->runtime : 0, $_duration, t("After this period, the poll will be closed automatically."));

  return $output;
}

function poll_help() {
 ?>
  <p>Drupal's poll module allows users with at least content posting privileges to submit multiple-choice questions that others can vote on.  Any user with sufficient privileges can vote.  Please note that this is fully controlled by Drupal's access control features.  For example, users might be required to login before voting (or even seeing the page where the voting occurs) or it could be open to the world.</p>
 <?php
}

function poll_insert($node) {
  if (!user_access("administer nodes")) {
    // Make sure all votes are 0 initially
    for ($i = 0; $i < count($node->chvotes); $i++) $node->chvotes[$i] = 0;
    $node->active = 1;
  }

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

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

function poll_link($type, $node = 0, $main) {
  if ($type == "menu.create" && user_access("post content")) {
    $links[] = lm(t("create poll"), array("mod" => "node", "op" => "add", "type" => "poll"), "", array("title" => t("Add a new poll.")));
  }
  else if ($type == "page" && user_access("access content")) {
    $links[] = lm(t("polls"), array("mod" => "poll"), "", array("title" => t("View the list of polls on this site.")));
  }
  else if ($type == "node" && $node->type == "poll") {
    /*
    ** Add links to allow the user to switch between the results and the voting
    ** form, if he/she hasn't voted yet.
    */

    // Make sure we have determined the 'allowvotes' flag
    poll_allowvotes($node);

    if ($node->allowvotes == 1) {
      global $pollresults;

      // Change the current URL: add/edit the value of pollresults[nid]
      if ($pollresults[$node->nid]) {
        // Disable
        $url = eregi_replace("pollresults\[$node->nid\]=1", "pollresults[$node->nid]=0", request_uri());

        $links[] = "<a href=\"$url\">". t("voting form") . "</a>";
      }
      else {
        // Enable
        if (strstr(request_uri(), "pollresults[$node->nid]=")) {
          $url = eregi_replace("pollresults\[$node->nid\]=0", "pollresults[$node->nid]=1", request_uri());
        }
        else {
          $url = request_uri() . (strstr(request_uri(), "?") ? "&amp;" : "?") ."pollresults[$node->nid]=1";
        }

        $links[] = "<a href=\"$url\">". t("view results") . "</a>";
      }
    }
  }
  return $links ? $links : array();
}

function poll_load($node) {
  // Load the appropriate choices into the $node object
  $poll = db_fetch_object(db_query("SELECT runtime, voters, 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_object($result)) {
    $poll->choice[$choice->chorder]  = $choice->chtext;
    $poll->chvotes[$choice->chorder] = $choice->chvotes;
  }

  // Reset allowvotes flag, will be filled in later on when needed.
  $poll->allowvotes = -1;
  return $poll;
}

function poll_node($field) {
  $info["name"] = t("poll");
  $info["description"] = t("A poll is a multiple-choice question which visitors can vote on.");
  return $info[$field];
}

function poll_page() {
  global $theme;

  $theme->header();
  $result = db_query("SELECT n.nid, n.title, p.active, SUM(c.chvotes) AS votes FROM node n LEFT JOIN poll p ON n.nid=p.nid LEFT JOIN poll_choices c ON n.nid=c.nid WHERE type = 'poll' AND status = '1' AND moderate = '0' GROUP BY n.nid, n.title, p.active, n.created ORDER BY n.created DESC");
  $output = "<ul>";
  while ($node = db_fetch_object($result)) {
    $output .= "<li>". l($node->title, array("id" => $node->nid)) ." - ". format_plural($node->votes, "vote", "votes") ." - ". ($node->active ? t("open") : t("closed")) ."</li>";
  }
  $output .= "</ul>";
  $theme->box(t("Polls"), $output);
  $theme->footer();
}

function poll_perm() {
  return array("vote on polls");
}

function poll_save($op, $node) {
  if ($op == "approve") {
    return array("status" => 1, "promote" => 1);
  }

  if ($op == "create") {
    if (user_access("administer nodes")) {
      return array("runtime", "active", "choice", "choices", "chvotes", "body" => "", "moderate" => 0, "status" => 1, "teaser" => poll_teaser($node));
    }
    else {
      return array("runtime", "active", "choice", "choices", "chvotes", "body" => "", "moderate" => 1, "status" => 0, "teaser" => poll_teaser($node));
    }
  }

  if ($op == "decline") {
    return array("status" => 0, "promote" => 0);
  }

  if ($op == "update") {
    return array("runtime", "active", "choice", "choices", "chvotes");
  }
}

function poll_system($field){
  $system["description"] = t("Enables your site to capture votes on different topics in the form of multiple choice questions.");
  return $system[$field];
}

function poll_teaser($node) {
  // Create a simple teaser that lists all the choices
  foreach ($node->choice as $k => $v) {
    if ($v != "") {
      $teaser .= "* $v\n";
    }
  }
  return $teaser;
}

function poll_view_voting(&$node, $main, $block, $links) {
  // Display the vote form
  global $theme;

  $url = request_uri();
  $output .= "<form action=\"$url\" method=\"post\">";
  $output .= "<table border=\"0\" align=\"center\"><tr><td>";

  if ($node->choice) {
    foreach ($node->choice as $key => $value) {
      if ($value != "") {
        $output .= "<input type=\"radio\" name=\"pollvote[$node->nid]\" value=\"$key\" /> $value<br />";
      }
    }
  }

  if ($block) {
    $output .= "</td></tr><tr><td><div align=\"center\">". form_submit(t("Vote")) ."</div></td></tr></table>";
  }
  else {
    $output .= "</td><td valign=\"middle\"><div align=\"right\">&nbsp;&nbsp;&nbsp;". form_submit(t("Vote")) ."</div></td></tr></table>";
  }

  $output .= $block ? "<div align=\"center\">". $theme->links($links) ."</div>" : "";
  $output .= "</form>";

  return $output;
}

function poll_view_results(&$node, $main, $block, $links) {
  // Display the results
  global $theme;

  // Count the votes and find the maximum
  if ($node->choice) {
    foreach ($node->choice as $key => $value) {
      $votestotal += $node->chvotes[$key];
      $votesmax = max($votesmax, $node->chvotes[$key]);
    }
    $votesmax = max($votesmax, 1);
  }

  /*
  ** Define CSS classes for the bars
  ** (note: style is not allowed outside <head>, but the alternative is very
  ** ugly and it seems to work in all browsers)
  */
  $output .= "<style type=\"text/css\">";
  $output .= "td.pollfg { background-color: ". $theme->foreground ."; font-size: 5pt; }";
  $output .= "td.pollbg { background-color: ". $theme->background ."; font-size: 5pt; }";
  $output .= "</style>";

  if ($node->choice) {
    foreach ($node->choice as $key => $value) {
      if ($value != "") {
        $width = round($node->chvotes[$key] * 100 / $votesmax);
        $percentage = round($node->chvotes[$key] * 100 / max($votestotal, 1));

        $output .= "<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"95%\" align=\"center\"><tr><td>$value</td><td><div align=\"right\"> $percentage%". (!$block ? " (". format_plural($node->chvotes[$key], "vote", "votes") .")" : "") ."</div></td></tr></table>";
        if ($width == 0) {
          $output .= "<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"95%\" align=\"center\"><tr><td class=\"pollbg\" width=\"100%\">&nbsp;</td></tr></table>";
        }
        else if ($width == 100) {
          $output .= "<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"95%\" align=\"center\"><tr><td class=\"pollfg\" width=\"100%\">&nbsp;</td></tr></table>";
        }
        else {
          $output .= "<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"95%\" align=\"center\"><tr><td class=\"pollfg\" width=\"". $width ."%\">&nbsp;</td><td class=\"pollbg\" width=\"". (100 - $width) ."%\">&nbsp;</td></tr></table>";
        }
      }
    }
  }
  $output .= "<br /><div align=\"center\">". t("Total votes") .": $votestotal";

  $output .= ($block ? "<br />". $theme->links($links) : "") ."</div>";

  return $output;
}

function poll_view_processvote(&$node) {
  global $pollvote;

  if (isset($pollvote[$node->nid]) && ($node->allowvotes == 1)) {
    if (!empty($node->choice[$pollvote[$node->nid]])) {
      $node->voters = $node->voters ? ($node->voters ." ". $node->polluserid) : $node->polluserid;
      db_query("UPDATE poll SET voters='%s' WHERE nid = '%d'", $node->voters, $node->nid);
      db_query("UPDATE poll_choices SET chvotes = chvotes + 1 WHERE nid = '%d' AND chorder = '%d'", $node->nid, $pollvote[$node->nid]);
      $node->allowvotes = 0;
      $node->chvotes[$pollvote[$node->nid]]++;
    }
  }
}

function poll_view(&$node, $main = 0, $block = 0) {
  global $theme, $user;

  /*
  ** When several polls are displayed on the same page (e.g. on the front page and in the side bar)
  ** we distinguish between them using the nid as index into associative arrays:
  ** $pollvote[nid]    - A user's vote
  ** $pollresults[nid] - When a user hasn't voted, he can choose to see the voting form or the results
  */
  global $pollresults;

  // Make sure we have determined the 'allowvotes' flag
  poll_allowvotes($node);

  // Because the voting form is embedded in the node-display, we process the data here
  poll_view_processvote($node);

  // Add extra link pointing to the list of polls (side-block only)
  if ($block) {
    $node->body = $node->teaser = "";

    $links = link_node($node, $main);
    $links[] = lm(t("older polls"), array("mod" => "poll"), "", array("title" => t("View the list of polls on this site.")));
  }

  if (($node->allowvotes == 1) && !$pollresults[$node->nid]) {
    $output = poll_view_voting($node, $main, $block, $links);
  }
  else {
    $output = poll_view_results($node, $main, $block, $links);
  }

  $node->body = $node->teaser = $output;

  // We also use poll_view() for the side-block
  if (!$block) {
    $theme->node($node, $main);
  }
}

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'", $node->nid);
  for ($i = 0; $i < $node->choices; $i++) {
    $choice->chtext = filter($node->choice[$i]);
    $choice->chvotes = (int)$node->chvotes[$i];
    $choice->chorder = $i;

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

?>