使用 Iron Params 访问表单上传的文件路径

Access to file path on form upload with Iron Params

我尝试使用 Iron params 获取上传文件的临时路径。我有这个请求处理程序:

fn handler(req: &mut Request) -> IronResult<Response> {
    let tmp_file_name = req.get_ref::<Params>().unwrap().find(&["file"]).unwrap();
    println!("{:?}", tmp_file_name);
    Ok( Response::with( (status::Ok, "Lorem Ipsum.") ) )
}

显示如下:

File { path: "/xxx/yyy", filename: Some("file.txt"), size: 123 }

但是如果我尝试访问路径:

println!("{:?}", tmp_file_name.path());

不编译:

error: attempted access of field `path` on type `&params::Value`, 
but no field with that name was found

我想我错过了一些关于类型的基础知识,但我不知道从哪里(重新)开始。

params::Value is not a params::File, but an enum that could contain a params::File.

这应该适用于适当的导入(未经测试):

match req.get_ref::<Params>().unwrap().find(&["file"]) {
  Some(&Value::File(ref file)) => {
    println!("{:?}", file.path())
  }
  _ => {
    println!("no file");
  }
}