PHP物件導向之工作單元

namespace woo\domain; //标识映射 class ObjectWatcher{ private $all = array(); //存放对象的小仓库 private $dirty = array(); //存放需要在数据库中修改的对象 private $new = array(); //存放需要在数据库中新增的对象 private $delete = array(); //存放需要在数据库中删除的对象 private static $instance; //单例 private function construct (){} static function instance(){ if(!self::$instance){ self::$instance = new ObjectWatcher(); } return self::$instance; } //获取一个唯一的标识,这里采用了领域类类名+ID的方式创建一个唯一标识，避免多个数据库表调用这个类时出现ID重复的问题 function globalKey(DomainObject $obj){ $key = get_class($obj) . "." . $obj->getId(); return $key; } //添加对象 static function add(DomainObject $obj){ $inst = self::instance(); $inst->all[$inst->globalKey($obj)] = $obj; } //获取对象 static function exists($classname,$id){ $inst = self::instance(); $key = "$classname.$id"; if(isset($inst->all[$key]){ return $inst->all[$key]; } return null; } //标记为需要删除的对象 static function addDelete(DomainObject $obj){ $self = self::instance(); $self->delete[$self->globalKey($obj)] = $obj; } //标记为需要修改的对象 static function addDirty(DomainObject $obj){ $inst = self::instance(); if(!in_array($obj,$inst->new,true)){ $inst->dirty[$inst->globalKey($obj)] = $obj; } } //标记为需要新增的对象 static function addNew(DomainObject $obj){ $inst = self::instance(); $inst->new[] = $obj; } //标记为干净的对象 static function addClean(DomainObject $obj){ $self = self::instance(); unset($self->delete[$self->globalKey($obj)]); unset($self->dirty[$self->globalKey($obj)]); $self->new = array_filter($self->new,function($a) use($obj) {return !($a === $obj);}); } //将上述需要增删改的对象与数据库交互进行处理 function performOperations(){ foreach($this->dirty as $key=>$obj){ $obj->finder()->update($obj); //$obj->finder()获取一个数据映射器 } foreach($this->new as $key=>$obj){ $obj->finder()->insert($obj); } $this->dirty = array(); $this->new = array(); } } //领域模型 abstract class DomainObject{ //抽象基类 private $id = -1; function construct ($id=null){ if(is_null($id)){ $this->markNew(); //初始化时即被标记为需要新增的对象了 } else { $this->id = $id; } } //调用了标识映射的标记对象的方法 function markNew(){ ObjectWatcher::addNew($this); } function markDeleted(){ ObjectWatcher::addDelete($this); } function markDirty(){ ObjectWatcher::addDirty($this); } function markClean(){ ObjectWatcher::addClean($this); } function setId($id){ $this->id = $id; } function getId(){ return $this->id; } function finder(){ return self::getFinder(get_class($this)); } //通过工厂类来实例化一个特定类型的数据映射器对象，例如VenueMapper //这个对象将被标识映射器中的performOperations方法调用用于与数据库交互进行增删改的操作 static function getFinder($type){ return HelperFactory::getFinder($type); } } class Venue extends DomainObject { private $name; private $spaces; function construct ($id = null,$name=null){ $this->name= $name; $this->spaces = self::getCollection('\\woo\\domain\\space'); parent::construct($id); } function setSpaces(SpaceCollection $spaces){ $this->spaces = $spaces; $this->markDirty(); //标记为需要修改的对象 } function addSpace(Space $space){ $this->spaces->add($space); $space->setVenue($this); $this->markDirty(); //标记为需要修改的对象 } function setName($name_s){ $this->name = $name_s; $this->markDirty(); //标记为需要修改的对象 } function getName(){ return $this->name; } } //领域模型 class Space extends DomainObject{ //......... function setName($name_s){ $this->name = $name_s; $this->markDirty(); } function setVenue(Venue $venue){ $this->venue = $venue; $this->markDirty(); } } //数据映射器 abstract class Mapper{ abstract static $PDO; //操作数据库的pdo对象 function construct (){ if(!isset(self::$PDO){ $dsn = \woo\base\ApplicationRegistry::getDSN(); if(is_null($dsn)){ throw new \woo\base\AppException("no dns"); } self::$PDO = new \PDO($dsn); self::$PDO->setAttribute(\PDO::ATTR_ERRMODE,\PDO::ERRMODE_EXCEPTION); } } //获取标记的对象 private function getFroMap($id){ return \woo\domain\ObjectWatcher::exists($this->targetClass(),$id); } //新增标记的对象 private function addToMap(\woo\domain\DomainObject $obj){////// return \woo\domain\ObjectWatcher::add($obj); } //将数据库数据映射为对象 function createObject($array){ $old = $this->getFromMap($array['id']); if($old){return $old;} $obj = $this->doCreateObject($array); $this->addToMap($obj); $obj->markClean(); return $obj; } function find($id){ //通过ID从数据库中获取一条数据并创建为对象 $old = $this->getFromMap($id); if($old){return $old} $this->selectStmt()->execute(array($id)); $array= $this->selectStmt()->fetch(); $this->selectStmt()->closeCursor(); if(!is_array($array)){ return null; } if(!isset($array['id'])){ return null; } $object = $this->createObject($array); $this->addToMap($object); return $object; } function insert(\woo\domain\DomainObject $obj){ //将对象数据插入数据库 $this->doInsert($obj); $this->addToMap($obj); } //需要在子类中实现的各个抽象方法 abstract function targetClass(); //获取类的类型 abstract function update(\woo\domain\DomainObject $objet); //修改操作 protected abstract function doCreateObject(array $array); //创建对象 protected abstract function selectStmt(); //查询操作 protected abstract function doInsert(\woo\domain\DomainObject $object); //插入操作 } class VenueMapper extends Mapper { function construct (){ parent::construct(); //预处理对象 $this->selectStmt = self::$PDO->prepare("select * from venue where id=?"); $this->updateStmt = self::$PDO->prepare("update venue set name=?,id=? where id=?"); $this->insertStmt = self::$PDO->prepare("insert into venue (name) values(?)"); } protected function getCollection(array $raw){ //将Space数组转换成对象集合 return new SpaceCollection($raw,$this); } protected function doCreateObject (array $array){ //创建对象 $obj = new \woo\domain\Venue($array['id']); $obj->setname($array['name']); return $obj; } protected function doInsert(\woo\domain\DomainObject $object){ //将对象插入数据库 print 'inserting'; debug_print_backtrace(); $values = array($object->getName()); $this->insertStmt->execute($values); $id = self::$PDO->lastInsertId(); $object->setId($id); } function update(\woo\domain\DomainObject $object){ //修改数据库数据 print "updation\n"; $values = array($object->getName(),$object->getId(),$object->getId()); $this->updateStmt->execute($values); } function selectStmt(){ //返回一个预处理对象 return $this->selectStmt; } } //客户端 $venue = new \woo\domain\Venue(null,"The Green Tree"); //在初始化时就被标记为新增对象了 $venue->addSpace(new \woo\domain\Space(null,"The Space Upstairs")); //这二行addSpace方法因为venue已经被标记新增所以不会再标记为修改对象,但是space在初始化的时候会被标记为新增对象 $venue->addSpace(new \woo\domain\Space(null,"The Bar Stage"));　　　　　　 \woo\domain\ObjectWatcher::instance()->performOperations(); //与数据库交互新增一条Venue数据,以及二条space数据