<?php
/**#@+
* @version 0.0.5
* @since 0.0.5
*/
/**
* @package POT
* @version 0.1.5
* @author Wrzasq <wrzasq@gmail.com>
* @copyright 2007 - 2008 (C) by Wrzasq
* @license http://www.gnu.org/licenses/lgpl-3.0.txt GNU Lesser General Public License, Version 3
* @todo future: Use fetchObject() to reduce amount of SQL queries.
* @todo future: Iterator classes (to map id => name iterations) with tutorial.
*/
/**
* Basic list class routines.
*
* <p>
* This class defines entire lists mechanism for classes that represents records set from OTServ database. All child classes only have to define {@link OTS_Base_List::init() init() method} to set table info for queries.
* </p>
*
* <p>
* Table on which list will operate has to contain integer <var>"id"</var> field and single row representing class has to support loading by this filed as key.
* </p>
*
* <p>
* This class is mostly usefull when you create own extensions for POT code.
* </p>
*
* @package POT
* @version 0.1.5
* @property-write int $limit Sets LIMIT clause.
* @property-write int $offset Sets OFFSET clause.
* @property-write OTS_SQLFilter $filter Sets filter for list SQL query.
*/
abstract class OTS_Base_List implements IOTS_DAO, Iterator, Countable
{
/**
* Database connection.
*
* @var PDO
* @version 0.1.5
*/
protected $db;
/**
* Limit for SELECT query.
*
* @var int
*/
private $limit = false;
/**
* Offset for SELECT query.
*
* @var int
*/
private $offset = false;
/**
* WHERE clause filter.
*
* @var OTS_SQLFilter
*/
private $filter = null;
/**
* List of sorting criteriums.
*
* @var array
*/
private $orderBy = array();
/**
* Query results.
*
* @var array
* @version 0.1.5
*/
protected $rows;
/**
* Default table name for queries.
*
* @var string
*/
protected $table;
/**
* Class of generated objects.
*
* @var string
*/
protected $class;
/**
* Sets database connection handler.
*
* @version 0.1.0
*/
public function __construct()
{
$this->db = POT::getInstance()->getDBHandle();
$this->init();
}
/**
* Sets list parameters.
*/
abstract public function init();
/**
* Magic PHP5 method.
*
* <p>
* Allows object serialisation.
* </p>
*
* @return array List of properties that should be saved.
*/
public function __sleep()
{
return array('limit', 'offset', 'filter', 'orderBy', 'table', 'class');
}
/**
* Magic PHP5 method.
*
* <p>
* Allows object unserialisation.
* </p>
*/
public function __wakeup()
{
$this->db = POT::getInstance()->getDBHandle();
}
/**
* Sets LIMIT clause.
*
* <p>
* Reduces amount of seleced rows up to given number.
* </p>
*
* @param int|bool $limit Limit for SELECT (false to reset).
*/
public function setLimit($limit = false)
{
if( is_int($limit) )
{
$this->limit = $limit;
}
else
{
$this->limit = false;
}
}
/**
* Sets OFFSET clause.
*
* <p>
* Moves starting rows of selected set to given position.
* </p>
*
* @param int|bool $offset Offset for SELECT (false to reset).
*/
public function setOffset($offset = false)
{
if( is_int($offset) )
{
$this->offset = $offset;
}
else
{
$this->offset = false;
}
}
/**
* Returns current row.
*
* <p>
* Returns object of class which handle single row representation. Object is initialised with ID of current position in result cursor.
* </p>
*
* @version 0.1.3
* @return OTS_Base_DAO Current row.
*/
public function current()
{
$id = current($this->rows);
$class = 'OTS_' . $this->class;
return new $class( (int) $id['id']);
}
/**
* Select rows from database.
*
* @throws PDOException On PDO operation error.
*/
public function rewind()
{
$this->rows = $this->db->query( $this->getSQL() )->fetchAll();
}
/**
* Moves to next row.
*/
public function next()
{
next($this->rows);
}
/**
* Current cursor position.
*
* @return mixed Array key.
*/
public function key()
{
return key($this->rows);
}
/**
* Checks if there are any rows left.
*
* @return bool Does next row exist.
*/
public function valid()
{
return key($this->rows) !== null;
}
/**
* Returns number of rows on list in current criterium.
*
* @version 0.1.5
* @return int Number of rows.
* @throws PDOException On PDO operation error.
*/
public function count()
{
return $this->db->query( $this->getSQL(true) )->fetchColumn();
}
/**
* Sets filter on list.
*
* <p>
* Call without argument to reset filter.
* </p>
*
* @param OTS_SQLFilter|null $filter Filter for list.
*/
public function setFilter(OTS_SQLFilter $filter = null)
{
$this->filter = $filter;
}
/**
* Clears ORDER BY clause.
*/
public function resetOrder()
{
$this->orderBy = array();
}
/**
* Appends sorting rule.
*
* <p>
* First parameter may be of type string, then it will be used as literal field name, or object of {@link OTS_SQLField OTS_SQLField class}, then it's representation will be used as qualiffied SQL identifier name.
* </p>
*
* <p>
* Note: Since 0.0.7 version <var>$field</var> parameter can be instance of {@link OTS_SQLField OTS_SQLField class}.
* </p>
*
* @version 0.0.7
* @param OTS_SQLField|string $field Field name.
* @param int $order Sorting order (ascending by default).
*/
public function orderBy($field, $order = POT::ORDER_ASC)
{
// constructs field name filter
if($field instanceof OTS_SQLField)
{
$table = $field->getTable();
// full table name
if( !empty($table) )
{
$table = $this->db->tableName($table) . '.';
}
$field = $table . $this->db->fieldName( $field->getName() );
}
// literal name
else
{
$field = $this->db->fieldName($field);
}
$this->orderBy[] = array('field' => $field, 'order' => $order);
}
/**
* Returns SQL query for SELECT.
*
* @version 0.1.5
* @param bool $count Shows if the SQL should be generated for COUNT() variant.
* @return string SQL query part.
*/
protected function getSQL($count = false)
{
// fields list
if($count)
{
$fields = 'COUNT(' . $this->db->tableName($this->table) . '.' . $this->db->fieldName('id') . ')';
}
else
{
$fields = $this->db->tableName($this->table) . '.' . $this->db->fieldName('id') . ' AS ' . $this->db->fieldName('id');
}
return $this->prepareSQL( array($fields) );
}
/**
* Returns generic SQL query that can be adaptated by child classes.
*
* @version 0.1.5
* @since 0.1.5
* @param array $fields Fields to be selected.
* @return string SQL query.
*/
protected function prepareSQL($fields)
{
$tables = array();
// generates tables list for current qeury
if( isset($this->filter) )
{
$tables = $this->filter->getTables();
}
// adds default table
if( !in_array($this->table, $tables) )
{
$tables[] = $this->table;
}
// prepares tables names
foreach($tables as &$name)
{
$name = $this->db->tableName($name);
}
// WHERE clause
if( isset($this->filter) )
{
$where = ' WHERE ' . $this->filter->__toString();
}
else
{
$where = '';
}
// ORDER BY clause
if(empty($this->orderBy) )
{
$orderBy = '';
}
else
{
$orderBy = array();
foreach($this->orderBy as $criterium)
{
switch($criterium['order'])
{
case POT::ORDER_ASC:
$orderBy[] = $criterium['field'] . ' ASC';
break;
case POT::ORDER_DESC:
$orderBy[] = $criterium['field'] . ' DESC';
break;
}
}
$orderBy = ' ORDER BY ' . implode(', ', $orderBy);
}
return 'SELECT ' . implode(', ', $fields) . ' FROM ' . implode(', ', $tables) . $where . $orderBy . $this->db->limit($this->limit, $this->offset);
}
/**
* Magic PHP5 method.
*
* @version 0.1.0
* @since 0.1.0
* @param string $name Property name.
* @param mixed $value Property value.
* @throws OutOfBoundsException For non-supported properties.
*/
public function __set($name, $value)
{
switch($name)
{
case 'limit':
$this->setLimit($value);
break;
case 'offset':
$this->setOffset($value);
break;
case 'filter':
$this->setFilter($value);
break;
default:
throw new OutOfBoundsException();
}
}
}
/**#@-*/
?>