Source for file RecordSet.class.php

<?php
 
/**
 * The RecordSet class holds a list of IDs and their Records in a specific record set.
 *
 * @package harmoni.datamanager
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: RecordSet.class.php,v 1.12 2007/09/04 20:25:32 adamfranco Exp $
 */
class RecordSet {
    
    var $_records;
    
    var $_dirty;
    
    function RecordSet() {
        $this->_records = array();
        
        $this->_dirty = false;
    }
    
    /**
     * Adds the records in the passed array to our set.
     * @param ref array $records An array of {@link Record} objects.
     * @access public
     * @return void 
     */
    function addRecords($records)
    {
        $this->_dirty = true;
        for ($i = 0; $i < count($records); $i++) {
            $this->_records[] =$records[$i];
        }
    }
 
    /**
     * Returns the number of records in this set.
     * @access public
     * @return int 
     */
    function numRecords()
    {
        return count($this->_records);
    }
    
    /**
     * Returns an array of records.
     * @access public
     * @return ref array
     */
    function getRecords()
    {
        return $this->_records;
    }
    
    /**
     * Returns if this set contains the passed {@link Record}
     * @param ref object $record
     * @access public
     * @return boolean 
     */
    function contains($record)
    {
        $id = $record->getID();
        if (!$id) return false;
        
        for ($i = 0; $i < count($this->_records); $i++) {
            if ($this->_records[$i]->getID() == $id) {
                return true;
            }
        }
        return false;
    }
    
    /**
     * Removes the given record from the set.
     * @param ref object $record A {@link Record} object.
     * @access public
     * @return void 
     */
    function removeRecord($record)
    {
        $id = $record->getID();
        if (!$id) {
            throwError(new Error("Could not remove record from set because the record does not yet have an ID.","RecordSet",false));
            return;
        }
        
        $newArr = array();
        for ($i = 0; $i < count($this->_records); $i++) {
            if ($this->_records[$i]->getID() != $id) $newArr[] =$this->_records[$i];
        }
        
        unset($this->_records);
        $this->_records =$newArr;
        
        $this->_dirty = true;
    }
    
    /**
     * Returns an array of Record IDs that we know about.
     * @return array 
     */
    function getRecordIDs() {
        $ids = array();
        for ($i = 0; $i < count($this->_records); $i++) {
            $id = $this->_records[$i]->getID();
            if ($id) $ids[] = $id;
        }
        
        return array_unique($ids);
    }
    
    /**
     * Returns an array of {@link Records} of the passed {@link Schema} {@link HarmoniType Type}.
     * @param string $id A type/ID string linked with a {@link Schema}.
     * @access public
     * @return ref array
     */
    function getRecordsByType($id)
    {
        $records =$this->getRecords();
        
        $return = array();
        for ($i = 0; $i < count($records); $i++) {
            if ($id == $records[$i]->getSchemaID()) {
                $return[] =$records[$i];
            }
        }
        
        return $return;
    }
    
    /**
     * Returns an array of records based on a label assigned previously. NOTE: this is a proposed method and has not been implemented.
     * @param string $label The string label of the {@link Records} to return.
     * @access public
     * @return ref array
     */
    function getRecordsByLabel($label)
    {
        // @todo decide if this is useful or if getRecordsByType is sufficient.
    }
    
    /**
     * Adds the given {@link Record} to our list.
     * @param ref object $record
     * @return void 
     */
    function add($record) {
        $this->_dirty = true;
        
        $this->_records[] =$record;
    }
    
    /**
     * This is a synonym for {@link RecordSet::add()}.
     * @param ref object $record
     * @access public
     * @return void 
     */
    function addRecord($record)
    {
        $this->add($record);
    }
    
    /**
     * Returns an array of merged tag-dates (as {@link DateAndTime} objects) which can be used to setup our Records as they were on a specific date.
     * @access public
     * @return array 
     */
    function getMergedTagDates()
    {
        // first get all the tags for each of our Records, then ask them for their dates. avoid duplicates
        $tagManager = Services::getService("RecordTagManager");
        $dates = array();
        $dateStrings = array();
        foreach ($this->getRecordIDs() as $id) {
            $tags =$tagManager->fetchTagDescriptors($id);
            foreach (array_keys($tags) as $key) {
                $date =$tags[$key]->getDate();
                $str = $date->asString();
                if (!in_array($str, $dateStrings)) {
                    $dateStrings[] = $str;
                    $dates[] =$date;
                }
            }
        }
        
        return $dates;
    }
    
    /**
     * Returns all of the {@link Record}s within this Set to the state they were in on the given date.
     * @param ref object $date A {@link DateAndTime} object.
     * @access public
     * @return boolean 
     */
    function revertToDate($date)
    {
        // this function goes through each Record, gets all the tags, and finds the one that has the closest tag
        // date to $date, as long as the tag date is *before* $date.
        // then, we activate that tag on the Record and commit it to the database
        $tagManager = Services::getService("RecordTagManager");
        
        for ($i = 0; $i < count($this->_records); $i++) {
            $id = $this->_records[$i]->getID();
            if (!$id) continue;
            $tags =$tagManager->fetchTags($id);
            
            $closest = null;
            $closestDate = null;
            foreach (array_keys($tags) as $key) {
                $tagDate =$tags[$key]->getDate();
                if ($tagDate->isLessThanOrEqualTo($date) 
                    && ($closestDate == null || $tagDate->isGreaterThan($closestDate))) 
                {
//                    print "-> for record $id, new best is " . $tagDate->asString() . " with sep = $sep<br/>";
                    $closestDate =$tagDate;
                    $closest =$tags[$key];
                }
            }
            
            if ($closest) {
                // we're going to activate the tag, then commit the Record
                $d =$closest->getDate();
                $this->_records[$i]->activateTag($closest);
                $this->_records[$i]->commit();
            }
        }
        return true;
    }
    
}
 
?>