ranking.inc in Advanced Poll 6
Same filename and directory in other branches
Handle ranking votes, e.g. choice A is preferred over choice B, which in turn is preferred over choice C.
File
modes/ranking.incView source
<?php
/**
* @file
* Handle ranking votes, e.g. choice A is preferred over choice B, which in turn is preferred over choice C.
*/
function advpoll_info_ranking() {
return array(
'name' => 'ranking',
'name_label' => t('Ranking'),
'description' => t('Rank a number of choices.'),
);
}
function advpoll_algorithms_ranking() {
return array(
'borda_count' => t('Borda count'),
'instant_runoff' => t('Instant runoff'),
);
}
function advpoll_voting_ranking_form(&$form_state, $node, $teaser, $page, $status) {
static $ranking_form_count = 0;
$form = array(
'#id' => 'advpoll_voting_ranking_form-' . $ranking_form_count++,
'#attributes' => array(
'class' => 'advpoll-vote',
),
'#node' => $node,
);
// Add write-in select box if write-ins are enabled and user has permission.
$handle_writeins = $node->writeins && user_access('add write-ins');
$form['ajax'] = array(
'#type' => 'hidden',
'#attributes' => array(
'class' => 'ajax',
),
);
$form['#attributes']['class'] .= ' drag-and-drop';
$form['js_order'] = array(
'#type' => 'hidden',
'#value' => '',
);
if ($node->max_choices) {
$max_choices = $node->max_choices;
}
else {
$max_choices = count($node->choice) - $node->writein_choices;
/*if ($handle_writeins) {
$max_choices++;
}
*/
}
$form['max_choices'] = array(
'#type' => 'hidden',
'#value' => $max_choices,
);
// TODO: figure out why this is here. shouldn't every poll have choices?
if (isset($node->choice)) {
$list = array();
$num_choices = count($node->choice);
// Generate the list of possible rankings
$choices[0] = '--';
for ($i = 1; $i <= $num_choices; $i++) {
if ($i == 1) {
$val = t('1st');
}
elseif ($i == 2) {
$val = t('2nd');
}
elseif ($i == 3) {
$val = t('3rd');
}
else {
$val = t($i . 'th');
}
$choices[$i] = $val;
}
// Fix to work around limitations in the current translation system. By
// listing the strings here they are made immediately available for
// translating. Listing up to 15 here, as it should be enough for most
// users. If more are needed they are made available for translating in
// Drupal when a poll with more than 15 choices has been created.
// TODO: Find a better solution for this.
array(
t('4th'),
t('5th'),
t('6th'),
t('7th'),
t('8th'),
t('9th'),
t('10th'),
t('11th'),
t('12th'),
t('13th'),
t('14th'),
t('15th'),
);
// List of poll choices, to be populated.
$form['choice'] = array(
'#tree' => TRUE,
);
// If previewing check the format against the current users permissions.
$check = $node->build_mode == NODE_BUILD_PREVIEW;
foreach ($node->choice as $key => $choice) {
// Don't show blank choices or write-in votes if the setting is disabled.
if ($choice['label'] && ($node->show_writeins || !$choice['writein'])) {
$form['choice'][$key] = array(
'#type' => 'select',
'#title' => _advpoll_choice_markup($choice['label'], $node->format, $check) . ($choice['writein'] ? ' ' . t('(write-in)') : ''),
'#options' => $choices,
);
}
}
if ($handle_writeins) {
$form['choice'][$key + 1] = array(
'#type' => 'select',
'#title' => t('(write-in)'),
'#options' => $choices,
'#attributes' => array(
'class' => 'advpoll-writeins',
),
);
// Key index of the write-in option.
$form['writein_key'] = array(
'#type' => 'value',
'#value' => $key + 1,
);
}
}
// Add write-in text field.
if ($handle_writeins) {
$form['writein_choice'] = array(
'#type' => 'textfield',
'#title' => t('Write-in vote'),
'#size' => 25,
);
}
$form['nid'] = array(
'#type' => 'hidden',
'#value' => $node->nid,
'#attributes' => array(
'class' => 'edit-nid',
),
);
// Hide vote button if user can't vote and instead display appropriate message.
if ($node->build_mode != NODE_BUILD_PREVIEW && advpoll_eligible($node) && $status == 'open') {
static $ranking_vote_count = 0;
$form['vote'] = array(
'#type' => 'submit',
'#value' => t('Vote'),
'#id' => 'edit-vote-rank-' . $ranking_vote_count++,
);
}
elseif ($node->build_mode == NODE_BUILD_PREVIEW) {
// Display nothing.
}
elseif ($status == 'pending') {
$form['message']['#value'] = t('This poll opens @time.', array(
'@time' => format_date($node->start_date),
));
}
else {
global $user;
$login_message = t('<a href="@login">Login</a> to vote in this poll.', array(
'@login' => url('user/login', array(
'query' => drupal_get_destination(),
)),
));
$form['message']['#value'] = $user->uid ? t('You are not eligible to vote in this poll.') : $login_message;
}
$form['#action'] = url('node/' . $node->nid);
// Set form caching because we could have multiple forms on the page.
// (from poll.module).
$form['#cache'] = TRUE;
return $form;
}
/**
* Process variables for advpoll-display-ranking-form.tpl.php.
*
* The variables array contains the following arguments:
* - $form
*
* @see advpoll-display-ranking-form.tpl.php
*/
function advpoll_preprocess_advpoll_voting_ranking_form(&$variables) {
$form =& $variables['form'];
$variables['message'] = drupal_render($form['message']);
// If write-ins are used on this form.
if (isset($form['writein_choice'])) {
$variables['writein_choice'] = drupal_render($form['writein_choice']);
}
$variables['form_id'] = $form['#id'];
// List of available choices in the poll.
$variables['choice_list'] = drupal_render($form['choice']);
// Take off the annoying colon & endlines that Drupal adds to each title.
$variables['choice_list'] = preg_replace('/[\\n\\r]*: <\\/label>[\\n\\r]*/i', '</label>', $variables['choice_list']);
// All remaining form elements.
$variables['form_submit'] = drupal_render($form);
// Add tabledrag JavaScript.
drupal_add_tabledrag($form['#id'] . '-table', 'order', 'self', 'advpoll-choice-order', NULL, NULL, FALSE);
}
function advpoll_view_results_ranking($node, $teaser, $page) {
$results = votingapi_select_results(array(
'content_type' => 'advpoll',
'content_id' => $node->nid,
));
$round_table = '';
// If no one has voted, $results = array() and thus is empty.
if (!empty($results)) {
// Temporary list of choices indexes for the ranking.
$ranking_list = array();
// Result object
$ranking = array();
$choices = array();
$poll = array();
$rounds = array();
foreach ($results as $result) {
$tag = $result['tag'];
if ($tag == '_advpoll') {
// Poll-wide cached value.
$poll[$result['function']] = $result['value'];
}
else {
if (strstr($tag, '_rounds_')) {
// Re-construct round data and extract the round from the tag.
$round = str_replace('_rounds_', '', $tag);
if (!isset($rounds[$round])) {
$rounds[$round] = array();
}
// $result->function actually stores $choice.
$rounds[$round][$result['function']] = $result['value'];
}
else {
if (isset($node->choice[$tag])) {
// Note: choices that have been removed will not pass the previous
// line's test even though their values are still in the vote table.
// Choice-specific cached value.
if ($result['function'] == 'ranking') {
$ranking_list[$result['value']][] = $tag;
}
else {
if (!isset($node->choice[$result['function']])) {
$choices[$tag][$result['function']] = $result['value'];
}
}
}
}
}
}
// Re-construct the rankings object.
foreach ($ranking_list as $i => $choice_list) {
$ranking[$i]->choices = array();
foreach ($choice_list as $choice_i) {
$ranking[$i]->choices[] = $choice_i;
if (isset($choices[$choice_i]['view_score'])) {
$ranking[$i]->view_score = $choices[$choice_i]['view_score'];
}
if (isset($choices[$choice_i]['raw_score'])) {
$ranking[$i]->raw_score = $choices[$choice_i]['raw_score'];
}
if (isset($choices[$choice_i]['percentage'])) {
$ranking[$i]->percentage = $choices[$choice_i]['percentage'];
}
}
}
$output = '';
if ($node->algorithm == 'borda_count') {
for ($i = 0; $i < count($ranking); $i++) {
$first_one = TRUE;
$this_rank = '';
// Loop through all choices with this ranking.
foreach ($ranking[$i]->choices as $choice) {
$label = isset($node->choice[$choice]) ? _advpoll_choice_markup($node->choice[$choice]['label'], $node->format, FALSE) . ($node->choice[$choice]['writein'] ? ' ' . t('(write-in)') : '') : t('(deleted)');
$this_rank .= ($first_one ? '' : ', ') . $label;
$first_one = FALSE;
}
$percentage = round(100 * (isset($ranking[$i]->percentage) ? $ranking[$i]->percentage : 0), 0);
$output .= theme('advpoll_bar', $this_rank, $percentage, $ranking[$i]->view_score);
}
}
else {
$output .= '<ol>';
for ($i = 0; $i < count($ranking); $i++) {
$output .= '<li> ';
$first_one = TRUE;
// If previewing check the format against the current users permissions.
$check = $node->build_mode == NODE_BUILD_PREVIEW;
// Loop through all choices with this ranking.
foreach ($ranking[$i]->choices as $choice) {
$label = isset($node->choice[$choice]) ? _advpoll_choice_markup($node->choice[$choice]['label'], $node->format, FALSE) . ($node->choice[$choice]['writein'] ? ' ' . t('(write-in)') : '') : t('(deleted)');
$output .= ($first_one ? '' : ', ') . $label;
$first_one = FALSE;
}
// Show the ranking's score if it exists (depends on algorithm).
if (isset($ranking[$i]->view_score)) {
$output .= ' (' . $ranking[$i]->view_score . '%)';
}
$output .= '</li>';
}
}
$output .= '</ol>';
if (user_access('inspect all votes') && isset($rounds)) {
if (count($rounds) > 0) {
$header[0] = t('Rounds');
$total_rounds = count($rounds);
for ($i = 0; $i < count($rounds); $i++) {
$choices = $rounds[$i];
if ($i + 1 == $total_rounds) {
// This is the last round.
$header[$i + 1] = t('Final');
}
else {
$header[$i + 1] = $i + 1;
}
if ($i == 0) {
$rows = array();
}
foreach ($node->choice as $key => $data) {
$rows[$key][0] = $data['label'];
$rows[$key][$i + 1] = isset($choices[$key]) && $choices[$key] ? $choices[$key] : '';
}
}
$round_table = theme('table', $header, $rows, array(), t('Per-round breakdown of votes for each choice'));
}
}
}
$output .= $round_table;
return array(
'results' => $output,
'votes' => $poll['total_votes'],
);
}
/**
* Calculate the results for a ranking poll based on the algorithm.
*
* @param $node
* The node object for the current poll
*
* @return
* Should return an object that include the following attributes
* -results : 2d array listing the aggregate preference, including ties
* -rounds : 2d array listing the per-choice vote count for each round and
* a status message indicating who was eliminated
* -totalVoters : the total number of voters who participated
*/
function advpoll_calculate_results_ranking(&$cache, $node) {
if ($node->algorithm == 'borda_count') {
$results = _advpoll_calculate_bordacount($node);
}
else {
$results = _advpoll_calculate_instantrunoff($node);
}
// Cache rankings.
// API: $cache[$tag][$type][$function] = $value (0 is the default $type)
if (isset($results->ranking)) {
for ($i = 0; $i < count($results->ranking); $i++) {
foreach ($results->ranking[$i]['choices'] as $choice) {
$cache[$choice][0]['ranking'] = $i;
if (isset($results->ranking[$i]['raw_score'])) {
$cache[$choice][0]['raw_score'] = $results->ranking[$i]['raw_score'];
}
if (isset($results->ranking[$i]['view_score'])) {
$cache[$choice][0]['view_score'] = $results->ranking[$i]['view_score'];
}
if (isset($results->ranking[$i]['percentage'])) {
$cache[$choice][0]['percentage'] = $results->ranking[$i]['percentage'];
}
}
}
}
// Cache round results.
if (isset($results->matrix)) {
foreach ($results->matrix as $i => $round) {
$key = '_rounds_' . $i;
$cache[$key] = array();
foreach ($round as $choice => $votes) {
$cache[$key][0][$choice] = count($votes);
}
}
}
// Cache total votes.
$cache['_advpoll'][0]['total_votes'] = isset($results->total_votes) ? $results->total_votes : 0;
// Cache total points (if it exists).
if (isset($results->total_points)) {
$cache['_advpoll'][0]['total_points'] = $results->total_points;
}
}
/**
* Calculate the results using borda count.
*
* @param $node
* The node object for the current poll.
*
* @return
* Should return an object that include the following attributes
* -results : 2d array listing the aggregate preference, including ties
* -rounds : 2d array listing the per-choice vote count for each round and
* a status message indicating who was eliminated
* -totalVoters : the total number of voters who participated
*/
function _advpoll_calculate_bordacount($node) {
$votes = array();
// ORDER BY value ASC lets us ensure no gaps.
$result = db_query("SELECT * FROM {votingapi_vote} v WHERE content_type = '%s' AND content_id = %d ORDER BY value ASC", 'advpoll', $node->nid);
while ($vobj = db_fetch_object($result)) {
$votes[] = $vobj;
}
if (count($votes) == 0) {
// No votes yet.
return array();
}
// Aggregate votes by user (uid if logged in, IP if anonymous)
// in ascending order of value.
$user_votes = array();
foreach ($votes as $vote) {
if ($vote->uid == 0) {
// Anonymous user.
$key = $vote->vote_source;
}
else {
// Logged-in user.
$key = $vote->uid;
}
$user_votes[$key][$vote->value] = $vote->tag;
}
$choice_votes = array();
$total_choices = count($node->choice);
$total_points = 0;
// Loop through each user's vote
foreach ($user_votes as $uid => $user_vote) {
foreach ($user_vote as $ranking => $choice) {
// Negative values are possible if choices were removed after vote
$vote_value = max($total_choices - $ranking, 0);
isset($choice_votes[$choice]) ? $choice_votes[$choice] += $vote_value : ($choice_votes[$choice] = $vote_value);
$total_points += $vote_value;
}
}
// Add any remaining choices that received no votes.
foreach ($node->choice as $i => $choice) {
if (!isset($choice_votes[$i])) {
// Didn't receive any votes
$choice_votes[$i] = 0;
}
}
// Sort descending (although there may be ties).
arsort($choice_votes);
// Figure out the final ranking.
$ranking = array();
$previous_total = -1;
$cur_result = -1;
foreach ($choice_votes as $choice => $total) {
if ($total != $previous_total) {
// Didn't tie with the previous score.
$cur_result++;
}
$ranking[$cur_result]['choices'][] = $choice;
$ranking[$cur_result]['raw_score'] = $total;
$ranking[$cur_result]['view_score'] = format_plural($total, '1 point', '@count points');
$ranking[$cur_result]['percentage'] = $total_points ? $total / $total_points : 0;
$previous_total = $total;
}
$total_votes = count($user_votes);
$result_obj->ranking = $ranking;
$result_obj->total_votes = $total_votes;
$result_obj->total_points = $total_points;
return $result_obj;
}
/**
* Calculate the results using instant-runoff voting.
*
* @param $node
* The node object for the current poll.
*
* @return
* Should return an object that include the following attributes.
* -results : 2d array listing the aggregate preference, including ties
* -rounds : 2d array listing the per-choice vote count for each round and
* a status message indicating who was eliminated
* -totalVoters : the total number of voters who participated
*/
function _advpoll_calculate_instantrunoff($node) {
$votes = array();
// ORDER BY value ASC lets us ensure no gaps.
$result = db_query("SELECT * FROM {votingapi_vote} v WHERE content_type = '%s' AND content_id = %d ORDER BY value ASC", 'advpoll', $node->nid);
while ($vobj = db_fetch_object($result)) {
$votes[] = $vobj;
}
if (count($votes) == 0) {
// No votes yet.
return array();
}
// Aggregate votes by user (uid if logged in, IP if anonymous)
// in ascending order of value.
$user_votes = array();
foreach ($votes as $vote) {
if ($vote->uid == 0) {
// Anonymous user.
$key = $vote->vote_source;
}
else {
// Logged-in user.
$key = $vote->uid;
}
// Note: relies on ORDER BY value ASC in vote-getting SQL query.
// Otherwise a later vote might have a lower value.
$user_votes[$key][] = $vote->tag;
}
$total_votes = count($user_votes);
// Log of 1st-place votes per choice in each round.
$round_log = array();
// Gradually append candidates as they are eliminated; end with the winner.
$reverse_ranking = array();
// If we eliminate one choice per round and have n choices, we should
// not be able to do more than n - 1 rounds.
$max_rounds = count($node->choice);
for ($round = 0; $round < $max_rounds; $round++) {
// Initialize cur_round.
$cur_round = array();
$total_choices = count($node->choice);
foreach ($node->choice as $key => $data) {
$cur_round[$key] = array();
}
// Loop through each user.
foreach ($user_votes as $key => $user_vote) {
// $user_vote[0] contains the user's first remaining preference.
$cur_round[$user_vote[0]][] = $key;
}
if ($round == 0) {
// This is the first round.
// Any choices with no first-place votes are considered eliminated.
foreach ($cur_round as $key => $choice_votes) {
if (count($choice_votes) == 0) {
unset($cur_round[$key]);
$reverse_ranking[0]['choices'][] = $key;
}
}
}
// Add the current round to the matrix.
$round_log[] = $cur_round;
// Calculate the min and max number of votes.
$min_votes = -1;
$max_votes = 0;
// Number of choices that have already been discarded.
$num_discarded = 0;
// Examine the number of votes each choice received this round.
foreach ($cur_round as $ch => $choice_votes) {
$num_votes = count($choice_votes);
if ($num_votes > $max_votes) {
$max_votes = $num_votes;
// Store current winner in case it has a majority.
$cur_winner = $ch;
}
// This choice has already been eliminated (theoretically)
// so don't count it as the minimum.
if ($num_votes == 0) {
$num_discarded++;
// XXX: Probably don't need this variable any more
}
else {
if ($num_votes != 0 && ($num_votes < $min_votes || $min_votes == -1)) {
$min_votes = $num_votes;
}
}
}
// If one choice has a majority of remaining users it wins.
// Note: we use count($user_votes) because some users may have incomplete
// ballots and may have already had all of their choices eliminated.
if ($max_votes > count($user_votes) / 2) {
// Prune out the winning choice if it's still in there.
if (isset($cur_round[$cur_winner])) {
unset($cur_round[$cur_winner]);
}
// Keep computing until we figure out all final rankings.
while (count($cur_round) > 0) {
// Loop through non-winning choices.
$current_place = array();
$min = -1;
foreach ($cur_round as $ch => $choice_votes) {
// Choice has already been eliminated, just unset it.
if (count($choice_votes) == 0) {
unset($cur_round[$ch]);
}
else {
if ($min == -1 || count($choice_votes) < $min) {
// New minimum.
$current_place = array(
$ch,
);
$min = count($choice_votes);
}
else {
if (count($choice_votes) == $min) {
// Tied for minimum.
$current_place[] = $ch;
}
}
}
}
// current_place will be empty the first iteration if some
// choices had no first-place votes and were eliminated
// at the beginning.
if (count($current_place) > 0) {
$reverse_ranking[]['choices'] = $current_place;
// Remove all choices that had the minimum.
foreach ($current_place as $ch_key) {
unset($cur_round[$ch_key]);
}
}
}
// Save a reversed version of the round log to help compute winnerPercent.
$revmat = array_reverse($round_log);
// The winner finally gets added
$reverse_ranking[]['choices'] = array(
$cur_winner,
);
$index = count($reverse_ranking) - 1;
$reverse_ranking[$index]['raw_score'] = round(count($revmat[0][$cur_winner]) * 100 / count($user_votes), 1);
$reverse_ranking[$index]['view_score'] = $reverse_ranking[$index]['raw_score'] . '%';
$result_obj->matrix = $round_log;
$result_obj->total_votes = $total_votes;
$result_obj->ranking = array_reverse($reverse_ranking);
return $result_obj;
}
// Since we're still here, no one has won, so eliminate one of the
// choices with the lowest number of votes.
// Find all choices with the minimum number of votes
$min_choices = array();
foreach ($cur_round as $ch => $choice_votes) {
if (count($choice_votes) == $min_votes) {
$min_choices[] = $ch;
}
}
// Randomly select the choice to eliminate out of the available choices.
// TODO: due to the randomness, this result must be cached after each vote.
$round_loser = array_rand($min_choices);
$reverse_ranking[]['choices'] = array(
$min_choices[$round_loser],
);
// Loop through the users who voted for the loser and redistribute.
foreach ($cur_round[$min_choices[$round_loser]] as $user_key) {
// Remove their current first preference.
array_shift($user_votes[$user_key]);
// Keep eliminating first preference until we run out or find an choice
// that hasn't been eliminated.
while ($cur_round[$user_votes[$user_key][0]] == array() && count($user_votes[$user_key]) > 0) {
array_shift($user_votes[$user_key]);
}
// If they have no more preferences, remove from list for simplicity.
if (count($user_votes[$user_key]) == 0) {
unset($user_votes[$user_key]);
}
}
}
// Loop detected. Signal user and record.
drupal_set_message(t('Could not find a solution within @rounds iterations.', array(
'@rounds' => $max_rounds,
)));
$result_obj->matrix = $round_log;
$result_obj->total_votes = $total_votes;
return $result_obj;
}
/**
* Implementation of the vote hook for the runoff module.
*
* This takes care of registering the vote in runoff nodes.
*/
function advpoll_voting_ranking_form_submit($form, &$form_state) {
$votes = array();
$node = $form['#node'];
// Do submission specific to writeins.
if (isset($form_state['values']['writein_key'])) {
_advpoll_writeins_voting_form_submit($node, $form_state, $votes, $form_state['values']['choice'][$form_state['values']['writein_key']]);
}
foreach ($form_state['values']['choice'] as $choice => $rank) {
$vote = array();
// Ignore write-in choice that has already been taken care of.
if (!$node->writeins || !isset($form_state['values']['writein_key']) || $choice != $form_state['values']['writein_key']) {
$vote['value'] = $rank;
// A zero value indicates they didn't rank that choice.
if ($vote['value'] != 0) {
$vote['value_type'] = 'option';
$vote['tag'] = $choice;
$vote['content_type'] = 'advpoll';
$vote['content_id'] = $node->nid;
$votes[] = $vote;
}
}
}
votingapi_set_votes($votes, array());
_advpoll_vote_response($node, $form_state);
}
/**
* Implementation of the vote validation hook for the runoff module.
*
* This checks if the submitted values are within range, if they are
* not empty, and if they are not repeated.
*
* @returns boolean false on invalid forms, true otherwise.
*/
function advpoll_voting_ranking_form_validate($form, &$form_state) {
$node = $form['#node'];
$ajax = $form_state['values']['ajax'];
// Check if user is eligible to vote.
if (!advpoll_eligible($node)) {
_advpoll_form_set_error('choice[', t('You are not allowed to vote in this poll.'), $ajax);
}
// Check if poll is active.
if (!_advpoll_is_active($node)) {
_advpoll_form_set_error('choice[', t('This poll is closed.'), $ajax);
}
// Whether the write-in option is selected.
$writein_option = FALSE;
$writein_text = isset($form_state['values']['writein_key']) ? $form_state['values']['writein_choice'] : '';
// Check if user has already voted.
list($voted, $cancel_vote) = _advpoll_user_voted($node->nid);
if ($voted) {
_advpoll_form_set_error('choice[', t('You have already voted in this poll.'), $ajax);
// Redirect to the current poll node to view the poll result instead of the voting form. This is only
// initiated for non-Ajax voting.
drupal_goto('node/' . $node->nid);
}
// Array used to check which values are set.
$set_values = array();
$num_choices = 0;
// Write-ins are enabled, user has permission, and the write-in box is checked.
if ($node->writeins && user_access('add write-ins') && $form_state['values']['choice'][$form_state['values']['writein_key']]) {
$num_choices++;
// Set a flag for additional checks.
$writein_option = TRUE;
}
foreach ($node->choice as $key => $choice) {
// Count the number of choices that are ranked.
if ($form_state['values']['choice'][$key]) {
$num_choices++;
}
$int_value = intval($form_state['values']['choice'][$key]);
// Mark this value as seen
isset($set_values[$int_value]) ? $set_values[$int_value]++ : ($set_values[$int_value] = 1);
// Check range
if ($int_value > count($node->choice) || $int_value < 0) {
// TODO: clean up this error message
$message = "Illegal rank for choice {$key}: {$int_value} (min: 1, max: " . count($node->choice) . ')';
_advpoll_form_set_error('choice][' . $key, $message, $ajax);
}
}
// Write-ins are enabled, user has permission, and the write-in box is checked.
if ($writein_option) {
$int_value = intval($form_state['values']['choice'][$form_state['values']['writein_key']]);
// Mark this value as seen
$set_values[$int_value]++;
// Check range
if ($int_value > count($node->choice) || $int_value < 0) {
// TODO: clean up this error message
$message = "Illegal rank for the write-in choice: {$int_value} (min: 1, max: " . count($node->choice) . ')';
_advpoll_form_set_error('choice][' . $form_state['values']['writein_key'], $message, $ajax);
}
}
// Do validation specific to writeins.
_advpoll_writeins_voting_form_validate($node, $writein_option, $writein_text, $ajax);
// Too many choices ranked.
if ($node->max_choices != 0 && $num_choices > $node->max_choices) {
$message = t('%num choices were selected but only %max are allowed.', array(
'%num' => $num_choices,
'%max' => $node->max_choices,
));
_advpoll_form_set_error('choice', $message, $ajax);
}
// Not enough choices ranked.
$min_choices = 1;
if ($num_choices < $min_choices) {
_advpoll_form_set_error('choice', t('At least one choice must be selected.'), $ajax);
}
// Check that multiple choices are not set to the same value.
foreach ($set_values as $val => $count) {
if ($val != 0 && $count > 1) {
$message = t('Multiple choices given the rank of %value.', array(
'%value' => $val,
));
_advpoll_form_set_error('choice', $message, $ajax);
}
}
}
/**
* Hook to handle a cancelled vote for a ranking poll.
*/
function advpoll_cancel_ranking($node, $user_vote) {
// Remove choice if this was the last vote for a write-in.
if ($node->writeins) {
$recalculate = FALSE;
foreach ($user_vote as $vote) {
if ($node->choice[$vote['tag']]['writein']) {
// Check if there are any other votes for this write-in.
$count = db_result(db_query('SELECT COUNT(1) FROM {votingapi_vote} WHERE content_id = %d AND tag = %d', $node->nid, $vote['tag']));
if ($count == 0) {
// Delete the write-in because no one else voted for it.
db_query('DELETE FROM {advpoll_choices} WHERE cid = %d', $vote['tag']);
$recalculate = TRUE;
watchdog('content', 'Removed write-in choice %choice after the last vote was cancelled.', array(
'%choice' => $node->choice[$vote['tag']]['label'],
));
}
}
}
if ($recalculate) {
votingapi_recalculate_results('advpoll', $node->nid);
}
}
}Functions
Name |
Description |
|---|---|
| advpoll_algorithms_ranking | |
| advpoll_calculate_results_ranking | Calculate the results for a ranking poll based on the algorithm. |
| advpoll_cancel_ranking | Hook to handle a cancelled vote for a ranking poll. |
| advpoll_info_ranking | @file Handle ranking votes, e.g. choice A is preferred over choice B, which in turn is preferred over choice C. |
| advpoll_preprocess_advpoll_voting_ranking_form | Process variables for advpoll-display-ranking-form.tpl.php. |
| advpoll_view_results_ranking | |
| advpoll_voting_ranking_form | |
| advpoll_voting_ranking_form_submit | Implementation of the vote hook for the runoff module. |
| advpoll_voting_ranking_form_validate | Implementation of the vote validation hook for the runoff module. |
| _advpoll_calculate_bordacount | Calculate the results using borda count. |
| _advpoll_calculate_instantrunoff | Calculate the results using instant-runoff voting. |