RSS Feed Readers Part IV - Filter Tools

// Performs a very simple filtering operation on rss feeds.
// configuration is stored in per user config filter, see example file for details.
// Setting 'default' to 'show' shows all articles EXCEPT if the defines words appear in article
// Setting 'default' to 'hide' hides all articles EXCEPT if the defines words appear in article
class SimpleArticleFilterExtension extends Minz_Extension {
  public function init() {
    $this->registerHook('entry_before_insert', array($this, 'checkForStrings'));

    // Was using this one for debug.  Doesn't store in Db.  
    // It leaves the count unmodified - nice to see how many skipped.... 
    //$this->registerHook('entry_before_display', array($this, 'checkForStrings'));
  }

  public function checkForStrings($entry) {
    // $entry is FreshRSS_Entry object
    // Accessible fields:
    // title, author, content, link, date, is_read, is_favourite, feed

    // Get json settings filename
    // Each user can have their own json file: "DefinedFilters.User.json"
    $current_user = Minz_Session::param('currentUser');
    $filename =  'DefinedFilters.'.$current_user.'.json';
    $filepath = join_path($this->getPath(), $filename);

    // Read the json file
    $jsonString = file_get_contents($filepath);
    $filterSettings = json_decode($jsonString);

    // Get the site settings if defined for this site
    $filterExists = false;
    foreach($filterSettings as $filterEntry)
    {
      // Unable to use the url as some rss feeds don't have it or are shared across many feeds ie twitter
      // Instead use feed id which is unique, which can be read from url eg f_8
      if (strpos($entry->feed(), $filterEntry->feedId) !== false)
      {
        $filterExists = true;

        $site = $filterEntry->site;
        $default = $filterEntry->default;
        $filters = $filterEntry->filters;
      }
    }

    //Got a filter, so do the processing
    if($filterExists)
    {
      // Combine title and content, so only doing one search
      $titlePlusContent = $entry->content().$entry->title(); 

      // Are any of our keywords in the title or body
      $filterMatch = false;
      foreach( $filters as $filter)
      {
        //Check. Case insensitive
        if ( stripos($titlePlusContent, $filter) !== false)
        {
          // Got a defined word.  NO need to keep checking
          $filterMatch = true;
          break;
        }
      }

      // Test for the scenarios where we wish to hide entry:
      // i)  Where default is to hide, and we didn't find one of the filters
      // ii) Where teh default action is to show, but we found one of our filters
      if(($default==="hide" && !$filterMatch) || ($default==="show" && $filterMatch))
      {
        // Don't return entry.  Has effect of hiding.
        // poss could set is_read, but doesn't work for entry_before_display hook
        return;
      }
    }

    // We want to see this one!
    return $entry;

  }// End checkForStrings
}//End Class