Yii常量的轻松管理

获取常量

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;
}

用法示例

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() );

小结

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。

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