我如何处理来自 multipart/formdata 的多个文件并使用 multer 存储它们

Question

我正在尝试创建一个考试应用程序，用户可以在其中添加多个问题，每个问题可能包含图像。这里我使用的是expressjs、reactjs、multer、mongodb。

问题是，当用户以 quertion1Data: "xxx", Question1Image: file, quertion2Data: "xxx", Question2Image: file 等表单数据发送多个问题数据时（我真的不知道如何发送多个问题） formdata 中的数据，比如我应该以什么方式发送，我提到的方式是否正确？而且我只在nodejs 中工作，我的其他团队成员在reactjs 中工作）。我如何首先使用 multer 将 Question1 的文件存储在我的服务器中的文件夹中，然后获取其路径，将其存储在 mongodb 中，获取其 _id，并将其与其他 Question1 字段链接，最后将 Question1 存储到 mongodb 并执行以下操作与其他问题相同。

路线如下：

 router.post("/addQuestions", authTeacherAdminSuperAdmin('Questions.Create'), uploadFile({ multipleImages: 'image' }), QuestionController.addQuestions);

中间件看起来像这样：

const multer = require('multer');
const fs = require('fs');
const path = require('path');
const sharp = require('sharp');
const { array } = require('joi');

function createDynamicFolders(folderPath) {
    if (!fs.existsSync(folderPath)) {
        fs.mkdirSync(folderPath, { recursive: true });
    }
}


function uploadFile(options) {
    const storage = multer.diskStorage({
        destination: (req, file, cb) => {
            console.log('Dynamic folder: ', req.dynamicFolder);
            const folderPath = ./public/uploads/${req.user.orgId}/${req.user.id}/${req.dynamicFolder};
            createDynamicFolders(folderPath);
            cb(null, folderPath);
        },
        filename: (req, file, cb) => {
            const ext = path.extname(file.originalname);
            const uniqueFilename = ${Date.now()}${ext};
            cb(null, uniqueFilename);
        }
    });

    const upload = multer({ storage: storage });

    return function (req, res, next) {
        console.log(options, "options")
        console.log(options, "options")
        console.log('Uploading file for field:', options.fieldName);
        if (Array.isArray(options)) {
            upload.fields(options)(req, res, async function (err) {
                if (err) {
                    console.error('Error during file upload:', err);
                    return res.status(500).json({ message: 'File Upload Error: ' + err.message });
                }
                next();
            });
        } else if (options.fieldName) {
            upload.single(options.fieldName)(req, res, async function (err) {
                if (err) {
                    console.error('Error during file upload:', err);
                    return res.status(500).json({ message: 'File Upload Error: ' + err.message });
                }
                // // Check if the uploaded file is an image (you might want to add more validation)
                // if (req.file.mimetype.startsWith('image')) {
                //     // Resize the image using Sharp
                //     const resizedImagePath = ./public/uploads/${req.user.orgId}/${req.user.id}/${req.dynamicFolder}/resized_${req.file.filename};

                //     await sharp(req.file.path)
                //         .resize(300, 200, { fit: 'inside' })
                //         .toFile(resizedImagePath);

                //     // You can save the resized image path or perform further actions with it
                //     req.resizedImagePath = resizedImagePath;
                // }
                next();
            });

        } else {

            upload.array(options.multipleImages)(req, res, async function (err) {
                if (err) {
                    console.error('Error during file upload:', err);
                    return res.status(500).json({ message: 'File Upload Error: ' + err.message });
                }
                req.files = req.files.map((item, index) => ({ ...item, index }));
                next();
            });

        }


    };
}

module.exports = uploadFile;

创建函数如下所示：

static create = async (data) => {
    try {
      let questions = []
      for (let index = 0; index < data.questions.length; index++) {
        const question = data.questions[index];
        if (question.image && Object.keys(question.image).length > 0) {

          const addImage = await FileServices.addFile(question.image);
          question.image = addImage._id
        } else {
          delete question.image
        }
        questions.push(question)
      }

      const result = {
        ...data,
        questions: questions.map((question) => ({
          ...question,
          organizationId: data.organizationId,
          deleted: data.deleted ? data.deleted : false,
          createdBy: data.createdBy
        }))
      };


      if (result.questions.length > 0) {
        const promises = result.questions.map(item => QuestionModel.create(item));
        return await Promise.all(promises)
      }
    } catch (error) {
      throw error;
    }
  }

Answer 1

您应该远离像

question1Data

这样的变量名称。

相反，您应该将问题存储在数组中，然后在服务器上为它们建立索引。

github 上的示例