如何为Yii2创建文件上载REST API控制器

Question

我正在使用Ionic框架进行移动应用程序开发.下面的Yii2 API代码可用于文件上传,但它不起作用.它显示以下错误:

i)未定义的偏移量:0.

ii)yii\db\BaseActiveRecord-> save()

public function actionNew() {
    $model = new Apiprofile();
    $userid = $_REQUEST['user_id'];
    $photo = $_FILES['photo'];
    $model->user_id = $userid;
    $model->photo = $photo;
    $name = $model->user_id;
    $model->file = UploadedFile::getInstance($model, 'photo');

    if($model->file) {
        $model->file->saveAs('uploads/photos/'.$name.'.'.$model->file->extension);
        $model->photo = $name.'.'.$model->file->extension;
        $model->save();
    }

    $name = $model->user_id;

    if($model->save()) {
        echo json_encode(array('status'=>1,'data'=>$model->attributes),JSON_PRETTY_PRINT);
    } else {
        echo json_encode(array('status'=>0,'error_code'=>400,'errors'=>$model->errors),JSON_PRETTY_PRINT);
    }
}