我经常在不同的地方使用模型中的常量(基本状态常量),当常量改变时我不得不在使用每处它的代码中修改。
为了解决这个问题我使用了一个方法 getConstants().
public static function getConstants($token,$objectClass) { $tokenLen = strlen($token); $reflection = new ReflectionClass($objectClass); //php built-in $allConstants = $reflection->getConstants(); //constants as array $tokenConstants = array(); foreach($allConstants as $name => $val) { if ( substr($name,0,$tokenLen) != $token ) continue; $tokenConstants[ $val ] = $val; } return $tokenConstants; }
为了给每个 ActiveRecord 类添加此方法，我们可以写个基类
class ActiveRecord extends CActiveRecord { /* Get class constants by token. If you set constants with same prefix, like: MY_STATUS_1 MY_STATUS_2 MY_STATUS_3 , you can get it by calling Class::getConstants('MY'); or Class::getConstants('MY_STATUS'); */ public static function getConstants($token,$objectClass) { $tokenLen = strlen($token); $reflection = new ReflectionClass($objectClass); //php built-in $allConstants = $reflection->getConstants(); //constants as array $tokenConstants = array(); foreach($allConstants as $name => $val) { if ( substr($name,0,$tokenLen) != $token ) continue; $tokenConstants[ $val ] = $val; } return $tokenConstants; } }
然后所有的模型类都继承此类而不是 CActiveRecord
class Media extends ActiveRecord { const TYPE_MUSIC = 'music'; const TYPE_VIDEO = 'video'; const TYPE_DOC = 'document'; const STATUS_ACTIVE = 'active'; const STATUS_REMOVED = 'removed'; //... }
在模型规则，方法，或模型外使用 self::getConstants()
class Media extends ActiveRecord { //.. public function rules() { return array( array('type', 'in','range' => self::getConstants('TYPE_',__CLASS__)), ); } //.. public static function getStatuses() { return self::getConstants('STATUS_',__CLASS__); } public static function getTypes() { return self::getConstants('TYPE_',__CLASS__); } }
其他地方
print_r( Media::getConstants('STATUS_','Media') ); //or create Media method and use simplified print_r( Media::getStatuses() );
当然如果你的模型中只有两个常量你可以不使用它，但当你的模型中有大量常量时建议你使用。
