Remove "Related projects" block until it provides relevant suggestions

Thanks! I'll go ahead and try to implement it :)

Explanation of the algorithm from my advisor Paul Resnick:

"...[This is] an integrated version that automatically adjusts which recommendations it makes based on user clickthroughs, through a technique called a Multi-Armed Bandit learning algorithm. All of the matching algorithms (based on text similarity, co-mention in conversations, or co-installation) generate initial candidate sets of items to recommend, but the actual items to recommend will adjust over time based on clickthroughs. the adjustments can happen offline, in batches, so they don't affect page load performance."

The code is checked in at https://svn.drupal.org/drupal/redesign_modules_sandbox/staging8/custom/

The same copy is posted here for easier review:

define('PIVOTS_PID', 6001);

/**
 * Implementation of hook_block()
 */
function pivots_project_block($op = 'list', $delta = 0, $edit = array()) {
  switch ($op) {
    case 'list':
      $blocks[0]['info'] = t('Pivots: related projects');
      return $blocks;

    case 'view':
      $block['subject'] = t('Related projects');
      $block['content'] = pivots_project_output();
      return $block;
  }
}

function pivots_project_output() {
  // skip nid=3060, the drupal project
  if (($node = project_get_project_from_menu()) && ($node->nid != 3060)) {
    $output = '';
    $node_id = $node->nid;
    $pivot_id = PIVOTS_PID;

    $ga_event = "{$node->nid}";
    $items = _pivots_project_generate_items($node_id, $pivot_id, variable_get('pivots_project_max_display', 5));
    if (!empty($items)) {
      foreach ($items as $position => $item) {
        $items[$position] = l($item['title'], "node/{$item['nid']}", array( 'attributes' => array(
                "onClick" => "javascript:pageTracker._trackEvent('PivotsClick_${pivot_id}', '${node_id}_{$item['nid']}');",
                "rel"     => "nofollow"
        )));
        $ga_event .= "_{$item['nid']}";
      }
      $output = theme('item_list', $items, $title);
    }
    else {
      $output = t("No related project yet. Please make suggestions. Thanks.");
    }
    $GLOBALS['conf']['googleanalytics_codesnippet_after'] .= "pageTracker._trackEvent('PivotsPageview_{$pivot_id}', '{$ga_event}');";

    $output .= _pivots_project_suggestbox($node->nid, $pivot_id);
    return $output;
  }
}


function _pivots_project_generate_items($node_id, $pivot_id, $limit) {

  db_set_active('pivots'); // NOTE: here we activate the pivots database.

  // if there's database failure, we just pretend nothing happens whatsoever. pivots_project returns nothing in this case.
  $matches = db_query("SELECT DISTINCT dst dest_id FROM {pivots_mab_match} WHERE pid=%d AND src=%d
        AND dst<>%d ORDER BY updated DESC, score DESC", $pivot_id, $node_id, $node_id);

  db_set_active();  // NOTE: change back to use the default database

  $count = 0;
  $items = array();
  while (($match = db_fetch_array($matches)) && $count < $limit) {
    $dest_id = $match['dest_id'];
    $result = db_query("SELECT title FROM {node} WHERE nid=%d AND status=1", $dest_id);
    // there might be cases that the node was deleted, or set to unpublished between pivots database refresh
    // so here we only count the valid node.
    $title = db_result($result);
    if ($title) {
      $items[] = array('nid' => $dest_id, 'title' => $title, 'pid' => $pivot_id);
      $count++;
    }
  }
  return $items;
}

function _pivots_project_suggestbox($node_id, $pivot_id) {
  $form = array();

  $form['suggest'] = array(
    '#type' => 'button',
    '#value' => t('Make a suggestion!'),
    '#weight' => 1,
    '#id' => 'pivots_project_suggestbutton'
  );

  $node = node_load($node_id);
  drupal_add_js("
      $(document).ready(function() {
        $('#pivots_project_suggestbutton').click(function() {
          var pattern = /^http[:][/][/]drupal[.]org[/]project[/]\w+$/;
          var suggestion = ''; //$('#pivots_project_suggestbox').val();
          var promption = 'Please suggest a related project to -{$node->title}- using its URL such as http://drupal.org/project/xxx. Thank you.';
          var error_promption = 'Your suggested URL does not look like http://drupal.org/project/xxx. Please try again, or press Cancel.';
          var success_promption = 'Thank you for suggesting a related project. It may or may not display soon according to the competition algorithm.';
          while (!suggestion.match(pattern)) {
            suggestion = prompt(promption);
            if (!suggestion) break;
            else promption = error_promption;
          }
          if (suggestion) {
            alert(success_promption);
            pageTracker._trackEvent('PivotsSuggest_${pivot_id}', '${node_id}_'+suggestion);
          }
        });
      });
    ", 'inline');

  return drupal_render_form('pivots_project_suggestbox', $form);
}

A working demo can be found at http://staging8.drupal.org/project/cck

patch attached. thanks!

@Michelle: Thanks for asking. May I ask a favor from you to review the code for me? I'll reciprocate if ever you'll need a code review. thanks!! --daniel

@drumm: I have uploaded a new patch with minor changes on the Google Analytics code. Yes. You are right. The patch only sends data to GA, but then we have a Python script (mab4do.py in attachment) that retrieves the GA data, saves the data in a local database hosted on d.o., and then updates the "related projects" block based on the GA clicks/suggestions data. The Python script would be running on scratchvm.drupal.org once a day. The algorithm we use is based on a particular version of the multi-armed bandit algorithm. It is documented in the paper Optimal learning and experimentation in bandit problems.

I have fully tested the patch on our local d.o. development environment. If the code review is fine, I can do "git apply patch" to the drupalorg module myself. Thanks.

Thanks drumm! New patch attached:

- made JS into an external file; used \/ instead of [/]
- URL patterns check for https
- made some code refactoring.

Thanks for the feedback drumm. New patch attached, and is tested successfully on my local d.o. dev.

-- Used Drupal.behaviors in JS
-- Instead of using [id^="pivots-block-list"], now it uses exact class/id match.
-- onclick events are now defined in JS and attached with JQuery.

If the patch looks fine, can you let me check in the patch myself? I'm waiting for #658218: get access to stagingvm in order to run the python update script that goes together with the patch. Thanks.

Thanks drumm for the suggestion and JSlint code. New patch attached:

-- changed the redundant $ga_data = "$node_id"; to be $ga_data = $node_id;
-- replaced original JS file with the JSLint output.

I have fully tested the patch on my local d.o. dev environment.

Got it. Sorry drumm for the trouble. I've tested it on my local d.o. dev server; don't know why it throws JS error on d.o....
I'm travelling now. Will resume in 10 days.

Sorry guys for not following up as the creator of the issue. For some reason I didn't receive updates on this issue until now.

The patch I submitted earlier used the "Multi-armed bandit" algorithm that automatically moves modules that got more clicks to the front of the "related projects" list. Overall the goal is to increases clicks rate on the "related projects" block, which is an indicator to show whether people find the recommendations useful or not.

I'm not sure whether there is still an interest to deploy this feature. If so, I can follow up and contribute more time to it.

An alternative is to use ApacheSolr's "More Like This" feature. Since d.o. already runs on ApacheSolr, it is the easiest approach to get it deployed. Our research back in 2009 on d.o. used A/B testing (actually multivariate testing) and showed that "More Like This" is the second best approach (in terms of clicks rate) compared to a few other alternatives. It is not ideal but still a decent option.