KeystoneJS:如何在上传到Cloudinary之前或上传过程中创建不同大小的多个版本的镜像？

npm install cloudinary

const keystone = require('keystone');
const cloudinary = require('cloudinary');

// 配置Cloudinary
cloudinary.config({
  cloud_name: 'your_cloud_name',
  api_key: 'your_api_key',
  api_secret: 'your_api_secret'
});

// 定义模型
const MyModel = keystone.createList('MyModel', {
  fields: {
    image: { type: keystone.fields.CloudinaryImage }
  }
});

// 在保存之前创建不同大小的多个版本的镜像
MyModel.schema.pre('save', async function (next) {
  const image = this.image;
  if (image) {
    // 创建缩略图
    const thumbnail = await cloudinary.v2.uploader.upload(image.path, {
      transformation: [
        { width: 100, height: 100, crop: 'thumb' },
        { quality: 'auto' }
      ]
    });
    this.thumbnail = thumbnail.secure_url;

    // 创建大图
    const largeImage = await cloudinary.v2.uploader.upload(image.path, {
      transformation: [
        { width: 800, height: 600, crop: 'limit' },
        { quality: 'auto' }
      ]
    });
    this.largeImage = largeImage.secure_url;
  }
  next();
});