GenericSequencerFilter.inc.php

<?php
import('lib.pkp.classes.filter.CompositeFilter');
 
class GenericSequencerFilter extends CompositeFilter {
   function __construct(&$filterGroup, $displayName = null) {
      parent::__construct($filterGroup, $displayName);
   }
 
 
   //
   // Implementing abstract template methods from PersistableFilter
   //
   function getClassName() {
      return 'lib.pkp.classes.filter.GenericSequencerFilter';
   }
 
 
   //
   // Implementing abstract template methods from Filter
   //
   function &process(&$input) {
      // Iterate over all filters and always feed the
      // output of one filter as input to the next
      // filter.
      $previousOutput = null;
      foreach($this->getFilters() as $filter) {
         if(is_null($previousOutput)) {
            // First filter
            $previousOutput =& $input;
         }
         $output = $filter->execute($previousOutput);
 
         // Propagate errors of sub-filters (if any)
         foreach($filter->getErrors() as $errorMessage) $this->addError($errorMessage);
 
         // If one filter returns null then we'll abort
         // execution of the filter chain.
         if (is_null($output)) break;
 
         unset($previousOutput);
         $previousOutput = $output;
      }
      return $output;
   }
}