pierre@1: <?php
pierre@1: // $Id: ad_weight_probability.module,v 1.1.4.5 2009/03/27 19:11:50 jeremy Exp $
pierre@1: 
pierre@1: /**
pierre@1:  * @file
pierre@1:  * A plug in for the ad.module, allowing an admin to set the probability that
pierre@1:  * a given advertisement will be displayed.
pierre@1:  *
pierre@1:  * Copyright (c) 2008-2009.
pierre@1:  *  Jeremy Andrews <jeremy@tag1consulting.com>.
pierre@1:  */
pierre@1: 
pierre@1: define('AD_PROBABILITY_DEFAULT', 100);
pierre@1: 
pierre@1: /**
pierre@1:  * Implementation of hook_form_alter().
pierre@1:  * Generate a form for assigning a weight to an advertisement.
pierre@1:  */
pierre@1: function ad_weight_probability_form_alter(&$form, &$form_state, $form_id) {
pierre@1:   if (isset($form['type']) && $form_id == 'ad_node_form') {
pierre@1:     $node = $form['#node'];
pierre@1:     $form['weighting'] = array(
pierre@1:       '#type' => 'fieldset',
pierre@1:       '#access' => user_access('configure ad probability'),
pierre@1:       '#title' => t('Weight'),
pierre@1:       '#collapsible' => TRUE,
pierre@1:       '#collapsed' => FALSE,
pierre@1:     );
pierre@1:     $form['weighting']['probability'] = array(
pierre@1:       '#type' => 'select',
pierre@1:       '#access' => user_access('configure ad probability'),
pierre@1:       '#title' => t('Probability'),
pierre@1:       '#options' => _ad_weight_probability_weights(),
pierre@1:       '#default_value' => isset($node->probability) ? $node->probability : 100,
pierre@1:       '#description' => t('The greater the probability, the more frequently this advertisement will be displayed.  An advertisement with a probablity of 2 will be displayed twice as frequently as an advertisement with a probability of 1.'),
pierre@1:     );
pierre@1:     $form['weighting']['#weight'] = -1;
pierre@1:   }
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Implementation of hook_nodeapi().
pierre@1:  */
pierre@1: function ad_weight_probability_nodeapi($node, $op, $arg = 0) {
pierre@1:   switch ($op) {
pierre@1:     case 'load':
pierre@1:       return _ad_weight_probability_node_load($node);
pierre@1:     case 'insert':
pierre@1:     case 'update':
pierre@1:       if (user_access('configure ad probability')) {
pierre@1:         // Fully load the node object to confirm that we are working with an
pierre@1:         // advertisement.
pierre@1:         $ad = node_load($node->nid);
pierre@1:         if (isset($ad->adtype)) {
pierre@1:           return _ad_weight_probability_node_save($node, $op);
pierre@1:         }
pierre@1:       }
pierre@1:     case 'delete':
pierre@1:       return _ad_weight_probability_node_delete($node);
pierre@1:   }
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Implementation of hook_perm().
pierre@1:  */
pierre@1: function ad_weight_probability_perm() {
pierre@1:   return array(t('configure ad probability'));
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Implementation of hook_ad_build_cache().
pierre@1:  */
pierre@1: function ad_weight_probability_ad_build_cache() {
pierre@1:   $cache = array();
pierre@1:   $active = db_query("SELECT a.aid, p.probability FROM {ads} a LEFT JOIN {ad_weight_probability} p ON a.aid = p.aid WHERE adstatus = 'active'");
pierre@1:   while ($ad = db_fetch_object($active)) {
pierre@1:     $probability = $ad->probability ? $ad->probability : AD_PROBABILITY_DEFAULT;
pierre@1:     $ads[$ad->aid] = $probability;
pierre@1:   }
pierre@1:   $cache['weight']['probability'] = $ads;
pierre@1:   $cache['weight']['hook_weight'] = array(
pierre@1:     'weight' => 10,
pierre@1:     'file' => drupal_get_path('module', 'ad_weight_probability') .'/ad_weight_probability.inc',
pierre@1:     'function' => 'ad_weight_probability_cache_filter',
pierre@1:   );
pierre@1:   return $cache;
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Helper function, load the probability from the database.
pierre@1:  */
pierre@1: function _ad_weight_probability_node_load($node) {
pierre@1:   $probability = (int)db_result(db_query('SELECT probability FROM {ad_weight_probability} WHERE aid = %d', $node->nid));
pierre@1:   $output['probability'] = $probability ? $probability : AD_PROBABILITY_DEFAULT;
pierre@1:   return $output;
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Helper function, save the probability to the database.
pierre@1:  */
pierre@1: function _ad_weight_probability_node_save($node) {
pierre@1:   if (is_object($node) && $node->nid) {
pierre@1:     db_query('UPDATE {ad_weight_probability} SET probability = %d WHERE aid = %d', $node->probability, $node->nid);
pierre@1:     if (!db_affected_rows()) {
pierre@1:       db_query('INSERT INTO {ad_weight_probability} (aid, probability) VALUES(%d, %d)', $node->nid, $node->probability);
pierre@1:     }
pierre@1:   }
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Helper function, delete the probability from the database.
pierre@1:  */
pierre@1: function _ad_weight_probability_node_delete($node) {
pierre@1:   db_query('DELETE FROM {ad_weight_probability} WHERE aid = %d', $node->nid);
pierre@1: }
pierre@1: 
pierre@1: /**
pierre@1:  * Available weight probabilities.
pierre@1:  */
pierre@1: function _ad_weight_probability_weights() {
pierre@1:   return array(
pierre@1:     25 => t('1/4'),
pierre@1:     33 => t('1/3'),
pierre@1:     50 => t('1/2'),
pierre@1:     100 => t('1'),
pierre@1:     200 => t('2'),
pierre@1:     300 => t('3'),
pierre@1:     400 => t('4'),
pierre@1:   );
pierre@1: }
pierre@1: