节点 js req.body 空返回

Question

我有一个非常奇怪的问题，我已经用同样的方式做了一些表格，一切都很好.. 我会尽量给你一些代码：

后端路由器js：

const express = require('express');
const { check } = require('express-validator');

const chatControllers = require('../controllers/chat-controllers');
const checkAuth = require('../middleware/check-auth');

const router = express.Router();

router.get('/', chatControllers.getChat);

router.use(checkAuth);

router.post(
  '/',
  [
    check('message')
      .not()
      .isEmpty()
  ],
  chatControllers.createChat
);

module.exports = router;

后端控制器js：

const createChat = async (req, res, next) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return next(
      new HttpError('Invalid, please check your data.', 422)
    );
  }

  const { message } = req.body;

  const createdChat = new Chat({
    message,
    creator: req.userData.userId
  });

  let user;
  try {
    user = await User.findById(req.userData.userId);
  } catch (err) {
    const error = new HttpError(
      'Creating message failed, please try again.',
      500
    );
    return next(error);
  }

  if (!user) {
    const error = new HttpError('Could not find user for provided id.', 404);
    return next(error);
  }

  try {
    const sess = await mongoose.startSession();
    sess.startTransaction();
    await createdChat.save({ session: sess });
  } catch (err) {
    const error = new HttpError(
      'Creating message failed, please try again.',
      500
    );
    return next(error);
  }

  res.status(201).json({ chat: createdChat });
};

和前端形式：

const Chat = () => {
  const auth = useContext(AuthContext);
  const { isLoading, error, sendRequest, clearError } = useHttpClient();
  const [formState, inputHandler] = useForm(
    {
      message: {
        value: '',
        isValid: false
      }
    },
    false
  );


  const chatSubmitHandler = async event => {
    event.preventDefault();
    try {
      const formData = new FormData();
      formData.append('message', formState.inputs.message.value);
      await sendRequest('http://localhost:5000/api/chat', 'POST', formData, {
        Authorization: 'Bearer ' + auth.token
      });
    } catch (err) {}
  };

  return (
    <React.Fragment>
      <Helmet>
        <title></title>
      </Helmet>
      
      <ErrorModal error={error} onClear={clearError} />

      <div className="container">
      <h1>CHAT</h1>
      <form className="chat-form" onSubmit={chatSubmitHandler}>

        <Input
          id="message"
          element="input"
          type="text"
          label="Message"
          validators={[VALIDATOR_REQUIRE()]}
          errorText="Please enter message."
          onInput={inputHandler}
        />

        <Button type="submit" disabled={!formState.isValid}>
          SEND
        </Button>
      </form>

      <div className="chat-body overflow-auto">
        message body
      </div>

      </div>
    </React.Fragment>
  );
};

export default Chat;

在应用程序 js 中，我已经需要聊天路由，并且我设置了标题和正文解析器，但在其他页面上非常奇怪，一切正常，但在这里我无法检索 req.body...

@我什至无法处理形成成功错误我得到：无效，请检查您的数据。我认为当我 console.log req 我看到 req.body 为空时，这个输入有问题......

Answer 1

您的快速服务器应用程序中需要某种请求负载解析器中间件。解析器实际上解析主体并在request 对象上创建一个名为body 的属性。通常对于以 JSON 作为请求体的 API，我们需要像这样使用bodyparser 中间件：

import bodyParser from 'body-parser';

// And then
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

但是如果你想使用多部分表单数据，那么你可以使用formidable作为中间件。

Answer 2

这很奇怪，我将在这里发布我的 app.js：

const fs = require('fs');
const path = require('path');

const express = require('express');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');

const companiesRoutes = require('./routes/companies-routes');
const usersRoutes = require('./routes/users-routes');
const adsRoutes = require('./routes/ads-routes');
const chatRoutes = require('./routes/chat-routes');
const HttpError = require('./models/http-error');
const { check } = require('express-validator');

const app = express();
const server = require("http").createServer(app);
const io = require("socket.io")(server, {
  cors: {
    origin: "http://localhost:3000",
    methods: ["GET", "POST"],
    credentials: true
  }
});

app.use(bodyParser.json());

app.use('/uploads/images', express.static(path.join('uploads', 'images')));
app.use('/uploads/videos', express.static(path.join('uploads', 'videos')));

app.use((req, res, next) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader(
    'Access-Control-Allow-Headers',
    'Origin, X-Requested-With, Content-Type, Accept, Authorization'
  );
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PATCH, DELETE');

  next();
});

app.use('/api/companies', companiesRoutes);
app.use('/api/users', usersRoutes);
app.use('/api/ads', adsRoutes);
app.use('/api/chat', chatRoutes);

app.use((req, res, next) => {
  const error = new HttpError('Could not find this route.', 404);
  throw error;
});

app.use((error, req, res, next) => {
  if (req.file) {
    fs.unlink(req.file.path, err => {
      console.log(err);
    });
  }
  if (res.headerSent) {
    return next(error);
  }
  res.status(error.code || 500);
  res.json({ message: error.message || 'An unknown error occurred!' });

}); 

mongoose
  .connect('mongodburllink', { useNewUrlParser: true })
  .then(() => {
    server.listen(5000);
  })
  .catch(err => {
    console.log(err);
  });

我有和其他表单用于创建和更新，一切正常，但在我上次聊天中我无法检索 req.body.. 我使用 express-validator 获取 req.body...看起来我错过了一些东西在这里，我在第一篇文章中发布了其他文件的完整代码，所以如果有人可以帮助我，我会很满意..