RatingExtension/Source Code

From PeacockWiki

<?php

################################################################################
# Core Code                                                                    #
################################################################################
# This section handles the core functions of this extension                    #
#   * Serving Files                                                            #
#   * Recording Ratings                                                        #
#   * Displaying Ratings                                                       #
################################################################################

#-------------------------------------------------------------------------------
# If html request requests file, serve file                                    #
# Files are requested by adding the ?file= GET parameter                       #
#-------------------------------------------------------------------------------
if(isset($_GET['file']))
  doFile();

#-------------------------------------------------------------------------------
# If html request contains rate information, process it                        #
# Rating information indicated by ?rate= GET parameter                         #
#                                                                              #
# MediaWiki engine is started by imitating the code in index.php               #
# This ensures database functions are working                                  #
#-------------------------------------------------------------------------------
if(isset($_GET['rate']))
{
  #Init
  #----------------
  require_once( 'includes/Setup.php' );
  require_once( "includes/Wiki.php" );
  $mediaWiki = new MediaWiki();
  $action = $wgRequest->getVal( 'action', 'view' );
  $title = $wgRequest->getVal( 'title' );
  $wgTitle = $mediaWiki->checkInitialQueries($title, $action, $wgOut,
    $wgRequest, $wgContLang);


  #Record Rating
  #----------------
  $sql = "REPLACE INTO `ratings` (`page_oldid`, `user_id`, `page_rating`) '.
    'VALUES (".$_GET['oldid'].", '".
    ($wgUser->getID()?$wgUser->getID():$wgUser->getName()).
    "', ".$_GET['rate'].")";
  $dbr =& wfGetDB( DB_WRITE );
  $res=wfQuery($sql, DB_WRITE, "");
  
  #Return to refering page and exit
  #----------------
  $wgTitle->invalidateCache();
  header( 'Location: '.$_SERVER["HTTP_REFERER"] ) ;
  die();
}

#-------------------------------------------------------------------------------
# Initialize extension                                                         #
# Sets up credit information, and hooks                                        #
#-------------------------------------------------------------------------------
if(isset($wgScriptPath))
{
$wgExtensionCredits["parserhook"][]=array(
  'name' => 'Rating Extension',
  'version' => '0.1',
  'url' => 'http://wiki.peacocktech.com/wiki/RatingExtension',
  'author' => '[http://about.peacocktech.com/trevorp/ Trevor Peacock]',
  'description' => 'Adds rating mechanism' );
  $wgHooks['OutputPageBeforeHTML'][] = 'InsertRating';
  $wgHooks['SkinTemplateSetupPageCss'][] = 'RatingCss';
}

#-------------------------------------------------------------------------------
# Insert rating to top of page                                                 #
#-------------------------------------------------------------------------------
function InsertRating($parserOutput, $text) {
  global $wgArticle;
  $oldid=getOldID($wgArticle);
  if($oldid)
    $text='<div id="ratingsection">'.
      getRatingHTML(getRating($oldid), $oldid).'</div>'.$text;
}



#-------------------------------------------------------------------------------
# Add CSS into skin for rating                                                 #
#-------------------------------------------------------------------------------
function RatingCss(&$css) {
  global $wgScriptPath;
  $css = "/*<![CDATA[*/".
  " @import \"$wgScriptPath/?file=rating.css\"; ".
  "/*]]>*/";
  return true;
}

################################################################################
# Supporting Functions                                                         #
################################################################################
# These functions support the core functions of the extension                  #
################################################################################

#-------------------------------------------------------------------------------
# Use the mediawiki engine to run the given sql code and return an object      #
# containing the first result of the query                                     #
#-------------------------------------------------------------------------------
#run sql code
function runQuery($sql)
{
  $dbr =& wfGetDB( DB_SLAVE );
  $res=wfQuery($sql, DB_SLAVE, "");
  return $dbr->fetchObject( $res );
}

#-------------------------------------------------------------------------------
# Return the oldid of the current page                                         #
# If oldid=0 (most current revision) take the latest oldid from the database   #
# for the current article                                                      #
#-------------------------------------------------------------------------------
function getOldID($article)
{
  $oldid=$article->getOldIDFromRequest();
  if($oldid!=0)
    return $oldid;
  $dbr =& wfGetDB( DB_SLAVE );
  $sql = "SELECT MAX(`rc_this_oldid`) AS `rc_this_oldid` FROM recentchanges '.
    'WHERE rc_cur_id=".$article->getID().";";
  $res=wfQuery($sql, DB_SLAVE, "");
  $row=$dbr->fetchObject( $res );
  if($row->rc_this_oldid)
    return $row->rc_this_oldid;
  return null;
}

#-------------------------------------------------------------------------------
# Performs a SQL query to fetch a rating for page oldid                        #
#-------------------------------------------------------------------------------
function getRatingData($oldid)
{
  $sql="SELECT COUNT(*) AS `count`, AVG(`page_rating`) AS `rating` '.
    'FROM ratings WHERE `page_oldid`=".$oldid." GROUP BY `page_oldid`;";
  return runQuery($sql);
}

#-------------------------------------------------------------------------------
# Fetch and calculate a rating for page oldid                                  #
# If there are not enough ratings for the current revivion, cycle              #
# older revisions to gather a minimum number of ratings                        #
#-------------------------------------------------------------------------------
function getRating($oldid)
{
  global $wgTitle;

  $countlimit=3;

  $ratingdata=getRatingData($oldid);
  $finalrating='?';
  $currentcount=number_format($ratingdata->count, 0);
  #If there are not enough ratings for the current revision
  if($rating->count<$countlimit)
  {
    $count=$ratingdata->count;
    $rating=$count*$ratingdata->rating;
    #cycle older revisions looking for more ratings
    while($oldid=$wgTitle->getPreviousRevisionID($oldid)) 
    {
      $ratingdata=getRatingData($oldid);
      #If still not enough ratings
      if($count+$ratingdata->count<$countlimit)
      {
        $count+=$ratingdata->count;
        $rating+=$ratingdata->count*$ratingdata->rating;
      }
      else #found enough ratings
      {
        $rating+=($countlimit-$count)*$ratingdata->rating;
        $count=$countlimit;
        $finalrating=$rating/$count;
        $oldid=false;
      }
    }
  }
  else
    $finalrating=$rating/$count;

  #format rating data
  if(is_numeric($finalrating))
    $finalrating=($finalrating-1)*1.25;
  $ratingarray=array('display'=>
      (is_numeric($finalrating)?number_format($finalrating, 2):$finalrating).
      " ($currentcount ratings)",
    'count'=>$currentcount,
    'rating'=>(is_numeric($finalrating)?$finalrating:0));
  return $ratingarray;
}

#-------------------------------------------------------------------------------
# Given the rating array and the page oldid, generate HTML code to be          #
# displayed                                                                    #
#-------------------------------------------------------------------------------
function getRatingHTML($rating, $oldid)
{
  global $wgTitle, $wgScriptPath;
  $countlimit=3;
  $html='';
  #generate stars
  for($x=0;$x<=4;$x++)
  {
    $html.='<a href="'.
      $wgTitle->getFullURL('oldid='.$oldid.'&rate='.($x+1)).'">'.
      '<img src="?file=star';
    if($rating['rating']>=$x+1) #larger than current star : filled
         $html.='4'.($rating['count']<$countlimit?'b':'');
    elseif($rating['rating']>$x+0.75) #3/4 current star : 3/4 filled
      $html.='3'.($rating['count']<$countlimit?'b':'');
    elseif($rating['rating']>$x+0.5) #1/2 current star : 1/2 filled
      $html.='2'.($rating['count']<$countlimit?'b':'');
    elseif($rating['rating']>$x+0.25) #1/4 current star : 1/4 filled
      $html.='1'.($rating['count']<$countlimit?'b':'');
    else #less than current star : empty
      $html.='0';
    $html.='.png" align=bottom/></a>'."\n";
  }
  #add text rating 
  $html.=' '.$rating['display'].'';
  $html=($rating['count']<$countlimit?'<b>'.$html.'</b>':$html);
  return $html;
}


#-------------------------------------------------------------------------------
# Return a file and exit.                                                      #
# File determined by ?file= GET parameter                                      #
#-------------------------------------------------------------------------------
function doFile()
{
  switch ($_GET['file'])
  {
    #Star .png files
    case "star0.png":
    case "star1.png":
    case "star1b.png":
    case "star2.png":
    case "star2b.png":
    case "star3.png":
    case "star3b.png":
    case "star4.png":
    case "star4b.png":
      header("Content-type: image/png");
      echo readFile('extensions/rating/'.$_GET['file']);
      die();
    #extension css styling
    case "rating.css":
      header("Content-type: text/css");
        ?>
#ratingsection {
  float: right;
  margin-top: -3.7em;
  padding: 3px;
}

#ratingsection b {
  color: red;
  padding: 4px;
}
<?php
      die();
  }
}

?>