adodb-active-record.inc.php

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<?php
/*

@version V4.94 23 Jan 2007  (c) 2000-2007 John Lim (jlim#natsoft.com.my). All rights reserved.
  Latest version is available at http://adodb.sourceforge.net
 
  Released under both BSD license and Lesser GPL library license. 
  Whenever there is any discrepancy between the two licenses, 
  the BSD license will take precedence.
  
  Active Record implementation. Superset of Zend Framework's.
  
  Version 0.07
  
  See http://www-128.ibm.com/developerworks/java/library/j-cb03076/?ca=dgr-lnxw01ActiveRecord 
  	for info on Ruby on Rails Active Record implementation
*/

global $_ADODB_ACTIVE_DBS;
global $ADODB_ACTIVE_CACHESECS; // set to true to enable caching of metadata such as field info
global $ACTIVE_RECORD_SAFETY; // set to false to disable safety checks

// array of ADODB_Active_DB's, indexed by ADODB_Active_Record->_dbat
$_ADODB_ACTIVE_DBS = array();
$ACTIVE_RECORD_SAFETY = true;

class ADODB_Active_DB {
	var $db; // ADOConnection
	var $tables; // assoc array of ADODB_Active_Table objects, indexed by tablename
}

class ADODB_Active_Table {
	var $name; // table name
	var $flds; // assoc array of adofieldobjs, indexed by fieldname
	var $keys; // assoc array of primary keys, indexed by fieldname
	var $_created; // only used when stored as a cached file
}

// returns index into $_ADODB_ACTIVE_DBS
function ADODB_SetDatabaseAdapter(&$db)
{
	global $_ADODB_ACTIVE_DBS;
	
		foreach($_ADODB_ACTIVE_DBS as $k => $d) {
			if (PHP_VERSION >= 5) {
				if ($d->db === $db) return $k;
			} else {
				if ($d->db->_connectionID === $db->_connectionID && $db->database == $d->db->database) 
					return $k;
			}
		}
		
		$obj = new ADODB_Active_DB();
		$obj->db =& $db;
		$obj->tables = array();
		
		$_ADODB_ACTIVE_DBS[] = $obj;
		
		return sizeof($_ADODB_ACTIVE_DBS)-1;
}


class ADODB_Active_Record {
	var $_dbat; // associative index pointing to ADODB_Active_DB eg. $ADODB_Active_DBS[_dbat]
	var $_table; // tablename, if set in class definition then use it as table name
	var $_tableat; // associative index pointing to ADODB_Active_Table, eg $ADODB_Active_DBS[_dbat]->tables[$this->_tableat]
	var $_where; // where clause set in Load()
	var $_saved = false; // indicates whether data is already inserted.
	var $_lasterr = false; // last error message
	var $_original = false; // the original values loaded or inserted, refreshed on update
	
	// should be static
	function SetDatabaseAdapter(&$db) 
	{
		return ADODB_SetDatabaseAdapter($db);
	}
	
	// php4 constructor
	function ADODB_Active_Record($table = false, $pkeyarr=false, $db=false)
	{
		ADODB_Active_Record::__construct($table,$pkeyarr,$db);
	}
	
	// php5 constructor
	function __construct($table = false, $pkeyarr=false, $db=false)
	{
	global $ADODB_ASSOC_CASE,$_ADODB_ACTIVE_DBS;
	
		if ($db == false && is_object($pkeyarr)) {
			$db = $pkeyarr;
			$pkeyarr = false;
		}
		
		if (!$table) { 
			if (!empty($this->_table)) $table = $this->_table;
			else $table = $this->_pluralize(get_class($this));
		}
		if ($db) {
			$this->_dbat = ADODB_Active_Record::SetDatabaseAdapter($db);
		} else
			$this->_dbat = sizeof($_ADODB_ACTIVE_DBS)-1;
		
		
		if ($this->_dbat < 0) $this->Error("No database connection set; use ADOdb_Active_Record::SetDatabaseAdapter(\$db)",'ADODB_Active_Record::__constructor');
		
		$this->_table = $table;
		$this->_tableat = $table; # reserved for setting the assoc value to a non-table name, eg. the sql string in future
		$this->UpdateActiveTable($pkeyarr);
	}
	
	function __wakeup()
	{
  		$class = get_class($this);
  		new $class;
	}
	
	function _pluralize($table)
	{
		$ut = strtoupper($table);
		$len = strlen($table);
		$lastc = $ut[$len-1];
		$lastc2 = substr($ut,$len-2);
		switch ($lastc) {
		case 'S':
			return $table.'es';	
		case 'Y':
			return substr($table,0,$len-1).'ies';
		case 'X':	
			return $table.'es';
		case 'H': 
			if ($lastc2 == 'CH' || $lastc2 == 'SH')
				return $table.'es';
		default:
			return $table.'s';
		}
	}
	
	//////////////////////////////////
	
	// update metadata
	function UpdateActiveTable($pkeys=false,$forceUpdate=false)
	{
	global $ADODB_ASSOC_CASE,$_ADODB_ACTIVE_DBS , $ADODB_CACHE_DIR, $ADODB_ACTIVE_CACHESECS;
	
		$activedb =& $_ADODB_ACTIVE_DBS[$this->_dbat];

		$table = $this->_table;
		$tables = $activedb->tables;
		$tableat = $this->_tableat;
		if (!$forceUpdate && !empty($tables[$tableat])) {
			$tobj =& $tables[$tableat];
			foreach($tobj->flds as $name => $fld) 
				$this->$name = null;
			return;
		}
		
		$db =& $activedb->db;
		$fname = $ADODB_CACHE_DIR . '/adodb_' . $db->databaseType . '_active_'. $table . '.cache';
		if (!$forceUpdate && $ADODB_ACTIVE_CACHESECS && $ADODB_CACHE_DIR && file_exists($fname)) {
			$fp = fopen($fname,'r');
			@flock($fp, LOCK_SH);
			$acttab = unserialize(fread($fp,100000));
			fclose($fp);
			if ($acttab->_created + $ADODB_ACTIVE_CACHESECS - (abs(rand()) % 16) > time()) { 
				// abs(rand()) randomizes deletion, reducing contention to delete/refresh file
				// ideally, you should cache at least 32 secs
				$activedb->tables[$table] = $acttab;
				
				//if ($db->debug) ADOConnection::outp("Reading cached active record file: $fname");
			  	return;
			} else if ($db->debug) {
				ADOConnection::outp("Refreshing cached active record file: $fname");
			}
		}
		$activetab = new ADODB_Active_Table();
		$activetab->name = $table;
		
		
		$cols = $db->MetaColumns($table);
		if (!$cols) {
			$this->Error("Invalid table name: $table",'UpdateActiveTable'); 
			return false;
		}
		$fld = reset($cols);
		if (!$pkeys) {
			if (isset($fld->primary_key)) {
				$pkeys = array();
				foreach($cols as $name => $fld) {
					if (!empty($fld->primary_key)) $pkeys[] = $name;
				}
			} else	
				$pkeys = $this->GetPrimaryKeys($db, $table);
		}
		if (empty($pkeys)) {
			$this->Error("No primary key found for table $table",'UpdateActiveTable');
			return false;
		}
		
		$attr = array();
		$keys = array();
		
		switch($ADODB_ASSOC_CASE) {
		case 0:
			foreach($cols as $name => $fldobj) {
				$name = strtolower($name);
				$this->$name = null;
				$attr[$name] = $fldobj;
			}
			foreach($pkeys as $k => $name) {
				$keys[strtolower($name)] = strtolower($name);
			}
			break;
			
		case 1: 
			foreach($cols as $name => $fldobj) {
				$name = strtoupper($name);
				$this->$name = null;
				$attr[$name] = $fldobj;
			}
			
			foreach($pkeys as $k => $name) {
				$keys[strtoupper($name)] = strtoupper($name);
			}
			break;
		default:
			foreach($cols as $name => $fldobj) {
				$name = ($fldobj->name);
				$this->$name = null;
				$attr[$name] = $fldobj;
			}
			foreach($pkeys as $k => $name) {
				$keys[$name] = $cols[$name]->name;
			}
			break;
		}
		
		$activetab->keys = $keys;
		$activetab->flds = $attr;

		if ($ADODB_ACTIVE_CACHESECS && $ADODB_CACHE_DIR) {
			$activetab->_created = time();
			$s = serialize($activetab);
			if (!function_exists('adodb_write_file')) include(ADODB_DIR.'/adodb-csvlib.inc.php');
			adodb_write_file($fname,$s);
		}
		$activedb->tables[$table] = $activetab;
	}
	
	function GetPrimaryKeys(&$db, $table)
	{
		return $db->MetaPrimaryKeys($table);
	}
	
	// error handler for both PHP4+5. 
	function Error($err,$fn)
	{
	global $_ADODB_ACTIVE_DBS;
	
		$fn = get_class($this).'::'.$fn;
		$this->_lasterr = $fn.': '.$err;
		
		if ($this->_dbat < 0) $db = false;
		else {
			$activedb = $_ADODB_ACTIVE_DBS[$this->_dbat];
			$db =& $activedb->db;
		}
		
		if (function_exists('adodb_throw')) {	
			if (!$db) adodb_throw('ADOdb_Active_Record', $fn, -1, $err, 0, 0, false);
			else adodb_throw($db->databaseType, $fn, -1, $err, 0, 0, $db);
		} else
			if (!$db || $db->debug) ADOConnection::outp($this->_lasterr);
		
	}
	
	// return last error message
	function ErrorMsg()
	{
		if (!function_exists('adodb_throw')) {
			if ($this->_dbat < 0) $db = false;
			else $db = $this->DB();
		
			// last error could be database error too
			if ($db && $db->ErrorMsg()) return $db->ErrorMsg();
		}
		return $this->_lasterr;
	}
	
	function ErrorNo() 
	{
		if ($this->_dbat < 0) return -9999; // no database connection...
		$db = $this->DB();
		
		return (int) $db->ErrorNo();
	}


	// retrieve ADOConnection from _ADODB_Active_DBs
	function &DB()
	{
	global $_ADODB_ACTIVE_DBS;
	
		if ($this->_dbat < 0) {
			$false = false;
			$this->Error("No database connection set: use ADOdb_Active_Record::SetDatabaseAdaptor(\$db)", "DB");
			return $false;
		}
		$activedb = $_ADODB_ACTIVE_DBS[$this->_dbat];
		$db =& $activedb->db;
		return $db;
	}
	
	// retrieve ADODB_Active_Table