嘗試從文件輸入 select a.csv 文件並將其傳遞到后端並使用 remix run 從后端讀取它

Question

我正在嘗試 select 一個 CSV 文件，其中包含一些列和使用文件輸入的數據。 這是CSV的內容

id,level,cvss,title,Vulnerability,Solution,reference, 963,LOW,7.8,Title - 963,Vulnerability - 963,Solution - 963,reference - 963, 964,CRITICAL,4.6,Title - 964,Vulnerability - 964,Solution - 964,reference - 964, 965,INFO,0,Title - 965,Vulnerability - 965,Solution - 965,reference - 965, 966,CRITICAL,10,Title - 966,Vulnerability - 966,Solution - 966,reference - 966, 967,HIGH,7.5,Title - 967,Vulnerability - 967,Solution - 967,reference - 967, 968,HIGH,5,Title - 968,Vulnerability - 968,Solution - 968,reference - 968, 969,MEDIUM,7.5,Title - 969,Vulnerability - 969,Solution - 969,reference - 969,

這是用戶界面的代碼

import { Form } from "@remix-run/react";
import type { ActionArgs, UploadHandler } from "@remix-run/server-runtime";
import {
  composeUploadHandlers,
  parseMultipartFormData,
} from "@remix-run/server-runtime/dist/formData";
import { createMemoryUploadHandler } from "@remix-run/server-runtime/dist/upload/memoryUploadHandler";
import { csvUploadHandler } from "~/models/code.server";

export async function action({ request, params }: ActionArgs) {
  const uploadHandler: UploadHandler = composeUploadHandlers(
    csvUploadHandler,
    createMemoryUploadHandler()
  );

  const formData = await parseMultipartFormData(request, uploadHandler);
  const selected_csv = formData.get("selected_csv");
  console.log("========== selected csv file: ", selected_csv);
  return selected_csv;
}

export default function codeListImport() {
  return (
    <div style={{ textAlign: "center" }}>
      <h1 style={{ marginBottom: 10 }}>UPDATE CODE LIST</h1>
      <Form method="post" encType="multipart/form-data">
        <input
          type="file"
          accept=".csv"
          name="selected_csv"
        />
        <button type="submit" className="btn btn-sm">
          UPLOAD CSV
        </button>
      </Form>
    </div>
  );
}

這是 code.server.ts 文件

export const csvUploadHandler: UploadHandler = async ({
  name,
  filename,
  data,
  contentType,
}) => {
  if (name !== "selected_csv") {
    return undefined;
  }

  console.log("===== file name", filename);
  console.log("===== data", data);
  console.log("===== content type", contentType);
};

我試圖使用 uploadHandler 提供的data獲取uploadHandler文件的內容。 我得到了 HTML 輸入元素的正確名稱、文件名以及內容類型。 但是當我控制日志data時，它會在日志中顯示：

我顯然不明白的是如何解碼這個 object

我已經閱讀了多個教程和許多 stackoverflow 帖子，但我仍然很難理解Symbol.asyncIterator到底是什么。 我是 ES6 的新手。 請幫我解決這個問題

Answer 1

在您的UploadHandler中，參數類型為UploadHandlerPart

export type UploadHandlerPart = {
  name: string;
  filename?: string;
  contentType: string;
  data: AsyncIterable<Uint8Array>;
};

所以data不是 CSV 字符串，它是字節的AsyncIterable 。 您需要將其轉換為字符串，然后從您的處理程序中返回它。

export const csvUploadHandler: UploadHandler = async ({
  name,
  filename,
  data,
  contentType,
}) => {
  if (name !== 'selected_csv') {
    return undefined;
  }
  // get data in chunks
  let chunks = [];
  for await (let chunk of data) {
    chunks.push(chunk);
  }
  // convert chunks to string using Blob()
  return await new Blob(chunks, { type: contentType }).text();
};

我這里有一個例子： https://stackblitz.com/edit/node-ubpgp5?file=app%2Froutes%2Findex.tsx

由於您實際上並未在csvUploadHandler中執行任何操作，因此您可以簡單地使用現有的 memoryUploadHandler()。 您的 csv 文件將在formData中作為File類型。

const uploadHandler = createMemoryUploadHandler();
const formData = await parseMultipartFormData(request, uploadHandler);
const csvFile = formData.get('selected_csv') as File;
const csv = await csvFile.text();