Dev.SN

I've updated my voting system to allow preferential voting (the previous method uses approval voting). It gives a score to each candidate based on its rank. E.g. if there are 10 candidates, and you give a candidate 1st preference, it gets 10 points, second preference gets 9 points, etc.

It's therefore functionally equivalent to "range voting".

<?php

/* How to use:
    Put all emails in an array with values in $emails["text"] and $emails["user_id"];
    Put the list of valid candidates in the function valid_candidate();
    Put the check for user-authorisation in function valid_user();
    Enjoy.
*/

$emails_array = array(
    array("user_id"=>234, "text"=>"
            option1 = 1
            option3 = 2
            optionwhatever = 3
        "),
    // Duplicate user, will be handled correctly.
    array("user_id"=>234, "text"=>"
        Oops forgot one I like:
        Optionfour = 2
        // Did I mention:
        option1=1
        "
        ),
    array("user_id"=>1234,
        "text"=>"
        // I hate option1
        Option1 = 6
        option2 = 1
        ")
    );

function valid_user($user_id){return true;} // put user filter in here if necessary
function valid_candidate($name){ return true;} // is the name one of the candidates?

$number_of_options = 6;

// Process all emails
foreach ($emails_array as $email)
{

  // Is it a valid registered user?
  if (valid_user($email["user_id"]))
  {

    // Process each line of the email
    $email_lines = explode("\n", trim($email["text"]));
    foreach ($email_lines as $this_line)
    {
      // Does it have an '=' sign and only one = sign
      $equals_sign = strpos($this_line, "=");
      if ($equals_sign !== false)
      {
        $cleaned_up_line_text = trim($this_line, ";.!\t\n\r\0");
        $parts_of_line = explode("=", $cleaned_up_line_text);
        if (count($parts_of_line) == 2)
        {
            // Is it a valid candidate and rank?
            // Candidate is in lower case.
            $candidate = strtolower(trim($parts_of_line[0]));
            $rank = intval(trim($parts_of_line[1]));
            if (valid_candidate($candidate) && ($rank > 0) && ($rank <= $number_of_options))
            {
                // Get the score for this candidate.
                // The score is the number of options - how far it is ranked below 1.
                // e.g. a rank of 1 would give it a score of $number_of_options.
                // a rank of 2 gives it a score of $number_of_options -1.
                // See "range voting".
                $score = $number_of_options - ($rank-1);

                // Make sure this vote for this user hasn't already been cast
                if (!isset($user_votes[$email["user_id"]]) ||
                    !isset($user_votes[$email["user_id"]][$candidate]))
                {
                    // Remember this user has voted for this name already.
                    $user_votes[$email["user_id"]][$candidate] = true;

                    // Count the vote towards the total
                    if (!isset($candidate_votes[$candidate]))
                        $candidate_votes[$candidate]=$score;
                    else $candidate_votes[$candidate]+= $score;
                }
            } // end of check for valid vote values.
        } // of check for correctly formatted vote
      } // of check for equals sign
    } // End of for loop for lines of email
  } // of check for valid user.
} // end of for loop for all emails.

print "votes:<br>";
print_r($user_votes);
print "<br><Br>";
print "candiate_votes<Br>";
print_r($candidate_votes);

?>