NodeJS / Restify：如何在API中接收文件上传？ [英] NodeJS/Restify: How can I recieve file upload in API?
问题描述
我正在尝试从移动应用程序上传图像文件（以本机编写，现在在iOS上运行）。
I'm trying to upload an image file from a mobile application (which is written in react native and now running on iOS).
文件发送到我的REST API，如下所示。我有两个问题：
The file is send to my REST API, which is shown below. I got two problems with that:
- 我没有得到
req.body，因为它总是一个空对象，虽然标题是正确提交的。 - 我想通过
gridfs-stream将收到的文件写入我的数据库（GridFS），但我不明白该代码的放置位置。
- I do not get
req.body, as it is always an empty object, although headers are submitted correctly. - I want to write the recieved file to my DB (GridFS) via
gridfs-stream, but I don't understand where to put that code.
API
const restify = require('restify')
const winston = require('winston')
const bunyanWinston = require('bunyan-winston-adapter')
const mongoose = require('mongoose')
const Grid = require('gridfs-stream')
const config = require('../config')
// Configure mongoose to work with javascript promises
mongoose.Promise = global.Promise
// Setting up server
const server = restify.createServer({
name: config.name,
version: config.version,
log: bunyanWinston.createAdapter(log)
})
server.use(restify.plugins.multipartBodyParser())
server.listen(config.port, () => {
mongoose.connection.on('open', (err) => {
server.post('/upload', (req, res, next) => {
console.log(req.headers) // <- returns headers as expected
/* Problem 1 */
console.log(req.body) // <- is empty object (unexpected)
res.send(200, { message: 'successful upload' })
res.end()
})
})
global.db = mongoose.connect(config.db.uri, { useMongoClient: true })
/* Problem 2: The recieved file should be stored to DB via `gridfs-stream` */
// I think this is the wrong place for this line...
var gfs = Grid(global.db, mongoose.mongo)
})
我试图找到错误，但我没有找到它，所以这里是数据，我在我的API中得到：
I tried to find the error, but I did not find it, so here is the data, which I get in my API:
标题
{
host: 'localhost:3000',
'content-type': 'multipart/form-data; boundary=pUqK6oKvY65OfhaQ3h01xWg0j4ajlanAA_e3MXVSna4F8kbg-zT0V3-PeJQm1QZ2ymcmUM',
'user-agent': 'User/1 CFNetwork/808.2.16 Darwin/15.6.0',
connection: 'keep-alive',
accept: '*/*',
'accept-language': 'en-us',
'accept-encoding': 'gzip, deflate',
'content-length': '315196'
}
body
{ }
为什么 body 为空？
React Native文件上传
这就是我将文件发送到API的方式。我还向您展示了一些变量的内容：
This is how I am sending the file to the API. I also show you the content of some variables:
async function upload (photo) {
console.log('photo', photo); // OUTPUT SHOWN BELOW
if (photo.uri) {
// Create the form data object
var data = new FormData()
data.append('picture', { uri: photo.uri, name: 'selfie.jpg', type: 'image/jpg' })
// Create the config object for the POST
const config = {
method: 'POST',
headers: {
'Accept': 'application/json'
},
body: data
}
console.log('config', config); // OUTPUT SHOWN BELOW
fetchProgress('http://localhost:3000/upload', {
method: 'post',
body: data
}, (progressEvent) => {
const progress = progressEvent.loaded / progressEvent.total
console.log(progress)
}).then((res) => console.log(res), (err) => console.log(err))
}
}
const fetchProgress = (url, opts = {}, onProgress) => {
console.log(url, opts)
return new Promise((resolve, reject) => {
var xhr = new XMLHttpRequest()
xhr.open(opts.method || 'get', url)
for (var k in opts.headers || {}) {
xhr.setRequestHeader(k, opts.headers[k])
}
xhr.onload = e => resolve(e.target)
xhr.onerror = reject
if (xhr.upload && onProgress) {
xhr.upload.onprogress = onProgress // event.loaded / event.total * 100 ; //event.lengthComputable
}
xhr.send(opts.body)
})
}
photo
{
fileSize: 314945,
origURL: 'assets-library://asset/asset.JPG?id=106E99A1-4F6A-45A2-B320-B0AD4A8E8473&ext=JPG',
longitude: -122.80317833333334,
fileName: 'IMG_0001.JPG',
height: 2848,
width: 4288,
latitude: 38.0374445,
timestamp: '2011-03-13T00:17:25Z',
isVertical: false,
uri: 'file:///Users/User/Library/Developer/CoreSimulator/Devices/D3FEFFA8-7446-42AB-BC7E-B6EB88DDA840/data/Containers/Data/Application/17CE8C0A-B781-4E56-9347-857E74055119/Documents/images/69C2F27F-9EEE-4611-853E-FC7FF6E5C373.jpg'
}
config
'http://localhost:3000/upload',
{
method: 'post',
body:
{
_parts:
[
[ 'picture',
{ uri: 'file:///Users/User/Library/Developer/CoreSimulator/Devices/D3FEFFA8-7446-42AB-BC7E-B6EB88DDA840/data/Containers/Data/Application/17CE8C0A-B781-4E56-9347-857E74055119/Documents/images/69C2F27F-9EEE-4611-853E-FC7FF6E5C373.jpg',
name: 'selfie.jpg',
type: 'image/jpg' }
]
]
}
}
我认为数据（应该在 config ）格式错误。为什么数组中有数组？
I think data (which should be send as body in config) has wrong format. Why is there an array in an array?
推荐答案
以下示例使用 react-native-fetch-blob 在React Native部分，Nodejs使用Express和 Formidable 在服务器端解析表单。
The example below uses react-native-fetch-blob at React Native part, and Nodejs with Express and Formidable to parse form at the server side.
让我们在确定后首先上传文件用户是否上传了照片或视频：
Let's first upload the file after determining whether user uploaded a photo or video:
RNFetchBlob.fetch(
'POST',
Constants.UPLOAD_URL + '/upload',
{
'Content-Type': 'multipart/form-data'
},
[
{
name: this.state.photoURL ? 'image' : 'video',
filename: 'avatar-foo.png',
type: 'image/foo',
data: RNFetchBlob.wrap(dataPath)
},
// elements without property `filename` will be sent as plain text
{ name: 'email', data: this.props.email },
{ name: 'title', data: this.state.text }
]
)
// listen to upload progress event
.uploadProgress((written, total) => {
console.log('uploaded', written / total);
this.setState({ uploadProgress: written / total });
})
// listen to download progress event
.progress((received, total) => {
console.log('progress', received / total);
})
.then(res => {
console.log(res.data); // we have the response of the server
this.props.navigation.goBack();
})
.catch(err => {
console.log(err);
});
};
同样，接收文件并相应地加载数据：
Similarly, receive file and load the data accordingly:
exports.upload = (req, res) => {
var form = new formidable.IncomingForm();
let data = {
email: '',
title: '',
photoURL: '',
videoURL: '',
};
// specify that we want to allow the user to upload multiple files in a single request
form.multiples = true;
// store all uploads in the /uploads directory
form.uploadDir = path.join(__dirname, '../../uploads');
form.on('file', (field, file) => {
let suffix = field === 'image' ? '.png' : '.mp4';
let timestamp = new Date().getTime().toString();
fs.rename(file.path, path.join(form.uploadDir, timestamp + suffix)); //save file with timestamp.
data[field === 'image' ? 'photoURL' : 'videoURL'] = timestamp + suffix;
});
form.on('field', (name, value) => {
data[name] = value;
});
form.on('error', err => {
console.log('An error has occured: \n ' + err);
});
form.on('end', () => {
// now we have a data object with fields updated.
});
form.parse(req);
};
并使用控制器功能：
let route = express.Router();
// other controller functions...
route.post('/upload', uploadController.upload);
app.use(route);
请务必阅读代码中包含的注释。 Datapath 是使用 react-native-image-picker 。您可以使用 react-native-progress 来显示上传进度。
Make sure you read the comments included in the code. Datapath is media's path (not base64 string) created after using react-native-image-picker . You can use react-native-progress to show upload progress.
查看react-native-fetch-blob的multipartform-data部分以供进一步参考： https://github.com/wkh237/react-native-fetch-blob#multipartform-data-示例 - 表格后数据与文件和数据
Check out multipartform-data section of react-native-fetch-blob for further reference: https://github.com/wkh237/react-native-fetch-blob#multipartform-data-example-post-form-data-with-file-and-data
这篇关于NodeJS / Restify：如何在API中接收文件上传？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
