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File content missing when i download from s3

I am using node.js aws sdk for s3 related methods. I have a method to download the file from s3 bucket.
I am downloading the file using the below code.
const downloadFileBase64 = async (payload) => {
let params = { Bucket: s3BucketName, Key: `${payload.folderName}/${payload.fileName}` };
try {
const response = await s3
.getObject(params, (err) => {
if (err) {
return err;
}
})
.promise();
return {
data: response.Body.toString('base64'),
fileName: payload.fileName
};
} catch (error) {
return Boom.badRequest(error.message);
}
};
Once i get the base64 content i am sending it over an email using sendgrid.
Issue: When i download small files everything is working fine. But when i download large files, some part of the file is missing in multiple pages. I just copy pasted the base64 in few online websites and downloaded the file from there, it's the same issue in those websites also. With this i concluded that there is some issue while returning the response from s3 itself. When i go to s3 and check it in the folder, it's showing proper file.
If you see the above screenshot, its the pdf which is having some random grey background in few pages and some text is also missing from the pdf.
I tried to use another method which just download buffer excluding the base64 conversion as shown below.
const downloadFileBuffer = async (payload) => {
let params = { Bucket: s3BucketName, Key: `${payload.folderName}/${payload.fileName}` };
try {
const response = await s3
.getObject(params, (err) => {
if (err) {
return err;
}
})
.promise();
return {
data: response.Body,
fileName: payload.fileName
};
} catch (error) {
return Boom.badRequest(error.message);
}
};
And once i get the file content in this above response, i am storing temporarily in a folder on server and then reading again and sending over email. But i am still having the same issue.
const fileContent = await docs.downloadFileBuffer({ payload: req.payload.action.dire });
await fs.writeFileSync(`${temp}testinggg.pdf`, fileContent?.data);
const fileData = await fs.readFileSync(`${temp}testinggg.pdf`, { encoding: 'base64' });
Any help on this issue is really appreciated.

After days of research and trying different ways, I found the issue. The issue was with .promise() used in s3.getObject(params, (err) => {}).promise();. Instead of that, I used callback using Promise as shown below. Now the file is properly showing the full content without missing any data.
const downloadFileBuffer = async (payload) => {
let params = { Bucket: s3BucketName, Key: `${payload.folderName}/${payload.fileName}` };
try {
return new Promise((resolve, reject) => {
s3.getObject(params, (err, response) => {
if (err) {
reject(err);
}
resolve({
data: response.Body,
fileName: payload.fileName
});
});
});
} catch (error) {
return Boom.badRequest(error.message);
}
};

How do I get uploaded image in next js and save it?

How do I get uploaded image in next.js API route and save it on public folder? I have front end ready. I'm uploading images to an endpoint using plain JavaScript.
here is the onSubmit function for uploading images. Suggest me if I'm doing it wrong here. The main question is how do I retrieve it?
const onSubmit=async(e)=>{
e.preventDefault();
const fd=new FormData()
fd.append('myfile',image.name)
let res=await fetch(`http://localhost:3000/api/upload`,{
method: 'POST',
headers: {
"Content-Type": "image/jpeg",
},
body: fd,
})
let response=await res.json();
one more bonus question, it's surely not a good idea to save the uploaded images on public folder. I have save it somewhere on the cloud.

This is the endpoint code I used for uploading image in nextjs, it requires some additional packages I will list them bellow also.
next-connect
multer
uuid
import nextConnect from "next-connect";
import multer from "multer";
import { v4 as uuidv4 } from "uuid";
let filename = uuidv4() + "-" + new Date().getTime();
const upload = multer({
storage: multer.diskStorage({
destination: "./public/uploads/profiles", // destination folder
filename: (req, file, cb) => cb(null, getFileName(file)),
}),
});
const getFileName = (file) => {
filename +=
"." +
file.originalname.substring(
file.originalname.lastIndexOf(".") + 1,
file.originalname.length
);
return filename;
};
const apiRoute = nextConnect({
onError(error, req, res) {
res
.status(501)
.json({ error: `Sorry something Happened! ${error.message}` });
},
onNoMatch(req, res) {
res.status(405).json({ error: `Method '${req.method}' Not Allowed` });
},
});
apiRoute.use(upload.array("file")); // attribute name you are sending the file by
apiRoute.post((req, res) => {
res.status(200).json({ data: `/uploads/profiles/${filename}` }); // response
});
export default apiRoute;
export const config = {
api: {
bodyParser: false, // Disallow body parsing, consume as stream
},
};

no Need to use any packages to handle file uploading you can use base64 to convert file to string and return it back to file by using "fs" module
why This way is beterr then using formData ?
because you duleing with normal post request where you can send any kind of data with it and use body parsere .
converting
const toBase64 = (file: File) => new Promise((resolve, reject) => {
const reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = () => resolve(reader.result);
reader.onerror = error => reject(error);
}
send a post request to server
const base64: string = await toBase64(file) as string;
const fileData = { base64, fileName: file.name };
const result = await api.post("/foo", fileData, name: "Salih", massage: "Hello World"})
converting base64 to file in server
function base64ToFile(file: { base64: string, fileName: string }) {
const fileContents = file.base64.replace(/^data:image\/png;base64,/, "");
fs.mkdirSync("./public/uploads", { recursive: true });
const fileName = `./public/uploads/${Date.now().toString() + file.fileName}`
fs.writeFile(fileName, fileContents, 'base64', function (err) { console.log(err) });
}

I suggest the popular and lightweight formidable library:
# install
yarn add formidable#v3 #types/formidable
// pages/api/file-upload.ts
import fs from "fs";
import path from "path";
import { File } from "formidable";
// Important for NextJS!
export const config = {
api: {
bodyParser: false,
},
};
export default async function handler(
req: NextApiRequest,
res: NextApiResponse<string>
) {
try {
// Parse request with formidable
const { fields, files } = await parseFormAsync(req);
// Files are always arrays (formidable v3+)
const myfile = (files["myfile"] as any as File[])[0];
// Save file in the public folder
saveFile(myfile, "./public/uploads");
// Return success
res.status(200).json("success!");
} catch (e) {
return res.status(500).json(e);
}
}
function saveFile(file: File, publicFolder: string): void {
const fileExt = path.extname(file.originalFilename || "");
fs.renameSync(file.filepath, `${publicFolder}/${file.newFilename}${fileExt}`);
}
// ./helpers/formidable.ts
import type { NextApiRequest } from "next";
import formidable from "formidable";
export type FormidableParseReturn = {
fields: formidable.Fields;
files: formidable.Files;
};
export async function parseFormAsync(
req: NextApiRequest,
formidableOptions?: formidable.Options
): Promise<FormidableParseReturn> {
const form = formidable(formidableOptions);
return await new Promise<FormidableParseReturn>((resolve, reject) => {
form.parse(req, async (err, fields, files) => {
if (err) {
reject(err);
}
resolve({ fields, files });
});
});
}
Bonus question
one more bonus question, it's surely not a good idea to save the uploaded images on public folder. I have save it somewhere on the cloud.
S3 and other cloud services
You can save on cloud services with Formidable.
See the official examples: https://github.com/node-formidable/formidable/blob/master/examples/store-files-on-s3.js
But you don't need to use cloud storage to protect private uploads. You can store them locally.
Working with private uploads locally
Saving:
Store the uploads in a non-public folder;
Ex. /private-uploads/{logged_user_id}/;
Reading:
Create an API page to fetch the file
Ex. https://.../uploads/{filename}
Fail if the file doesn't belong to the authenticated user;
Send the file as the response;
Security:
With the above folder scheme, hackers can use .. and similar on the filename to obtain unauthorized access;
Sanitize the filename having this in mind (ex. only allow alphanumeric characters);
Alternatively, use a database table to control ownership instead of a folder scheme;

AWS S3 file upload with Node.js: Unsupported body payload error

I am trying to get my node.js backend to upload a file to AWS S3, which it got in a post request from my front-end. This is what my function looks like:
async function uploadFile(file){
var uploadParams = {Bucket: '<bucket-name>', Key: file.name, Body: file};
s3.upload (uploadParams, function (err, data) {
if (err) {
console.log("Error", err);
} if (data) {
console.log("Upload Success", data.Location);
}
});
}
When I try uploading the file this way, I get an Unsupported Body Payload Error...
I used fileStream.createReadStream() in the past to upload files saves in a directory on the server, but creating a fileStream did not work for me, since there is no path parameter to pass here.
EDIT:
The file object is created in the angular frontend of my web application. This it the relevant html code where the file is uploaded by a user:
<div class="form-group">
<label for="file">Choose File</label>
<input type="file" id="file"(change)="handleFileInput($event.target.files)">
</div>
If the event occurs, the handleFileInput(files: FileList) method in the corresponding component is called:
handleFileInput(files: FileList) {
// should result in array in case multiple files are uploaded
this.fileToUpload = files.item(0);
// actually upload the file
this.uploadFileToActivity();
// used to check whether we really received the file
console.log(this.fileToUpload);
console.log(typeof this.fileToUpload)
}
uploadFileToActivity() {
this.fileUploadService.postFile(this.fileToUpload).subscribe(data => {
// do something, if upload success
}, error => {
console.log(error);
});
}
the postFile(fileToUpload: File) method of the file-upload service is used to make the post request:
postFile(fileToUpload: File): Observable<Boolean> {
console.log(fileToUpload.name);
const endpoint = '/api/fileupload/single';
const formData: FormData = new FormData();
formData.append('fileKey', fileToUpload, fileToUpload.name);
return this.httpClient
.post(endpoint, formData/*, { headers: yourHeadersConfig }*/)
.pipe(
map(() => { return true; }),
catchError((e) => this.handleError(e)),
);
}
Here is the the server-side code that receives the file and then calls the uploadFile(file) function:
app.post('/api/fileupload/single', async (req, res) => {
try {
if(!req.files) {
res.send({
status: false,
message: 'No file uploaded'
});
} else {
let file = req.files.fileKey;
uploadFile(file);
//send response
res.send({
status: true,
message: 'File is uploaded',
data: {
name: file.name,
mimetype: file.mimetype,
size: file.size
}
});
}
} catch (err) {
res.status(500).send(err);
}
});
Thank you very much for your help in solving this!
Best regards, Samuel

Best way is stream the file. Assuming you are. reading it from disk. You could do this
const fs = require("fs");
const aws = require("aws-sdk");
const s3Client = new aws.S3();
const Bucket = 'somebucket';
const stream = fs.createReadStream("file.pdf");
const Key = stream.path;
const response = await s3Client.upload({Bucket, Key, Body: stream}).promise();
console.log(response);

How to get file properties and upload a file from ionic 4?

I am trying to upload a file from mobile to google bucket using ionic 4. Although a file can upload into the could. I am struggling to get the file properties out of file object.
Here is my method,
async selectAFile() {
const uploadFileDetails = {
name: '',
contentLength: '',
size: '',
type: '',
path: '',
};
this.fileChooser.open().then(uri => {
this.file.resolveLocalFilesystemUrl(uri).then(newUrl => {
let dirPath = newUrl.nativeURL;
const dirPathSegments = dirPath.split('/');
dirPathSegments.pop();
dirPath = dirPathSegments.join('/');
(<any>window).resolveLocalFileSystemURL(
newUrl.nativeURL,
function(fileEntry) {
uploadFileDetails.path = newUrl.nativeURL;
const file: any = getFileFromFileEntry(fileEntry);
//log 01
console.log({ file });
uploadFileDetails.size = file.size;
uploadFileDetails.name = `${newUrl.name
.split(':')
.pop()}.${file.type.split('/').pop()}`;
uploadFileDetails.type = file.type;
async function getFileFromFileEntry(fileEntry) {
try {
return await new Promise((resolve, reject) =>
fileEntry.file(resolve, reject)
);
} catch (err) {
console.log(err);
}
}
},
function(e) {
console.error(e);
}
);
});
});
// here uploadFileDetails is simller to what I declared at the top ;)
// I wan't this to be populated with file properties
// console.log(uploadFileDetails.name) --> //''
const uploadUrl = await this.getUploadUrl(uploadFileDetails);
const response: any = this.uploadFile(
uploadFileDetails,
uploadUrl
);
response
.then(function(success) {
console.log({ success });
this.presentToast('File uploaded successfully.');
this.loadFiles();
})
.catch(function(error) {
console.log({ error });
});
}
even though I can console.log the file in log 01. I am unable to get file properties like, size, name, type out of the resolveLocalFileSystemURL function. basically, I am unable to populate uploadFileDetails object. What am I doing wrong? Thank you in advance.

you actually need 4 Ionic Cordova plugins to upload a file after getting all the metadata of a file.
FileChooser
Opens the file picker on Android for the user to select a file, returns a file URI.
FilePath
This plugin allows you to resolve the native filesystem path for Android content URIs and is based on code in the aFileChooser library.
File
This plugin implements a File API allowing read/write access to files residing on the device.
File Trnafer
This plugin allows you to upload and download files.
getting the file's metadata.
file.resolveLocalFilesystemUrl with fileEntry.file give you all the metadata you need, except the file name. There is a property called name in the metadata but it always contains value content.
To get the human readable file name you need filePath. But remember you can't use returning file path to retrieve metadata. For that, you need the original url from fileChooser.
filePathUrl.substring(filePathUrl.lastIndexOf('/') + 1) is used to get only file name from filePath.
You need nativeURL of the file in order to upload it. Using file path returning from filePath is not going to work.
getFileInfo(): Promise<any> {
return this.fileChooser.open().then(fileURI => {
return this.filePath.resolveNativePath(fileURI).then(filePathUrl => {
return this.file
.resolveLocalFilesystemUrl(fileURI)
.then((fileEntry: any) => {
return new Promise((resolve, reject) => {
fileEntry.file(
meta =>
resolve({
nativeURL: fileEntry.nativeURL,
fileNameFromPath: filePathUrl.substring(filePathUrl.lastIndexOf('/') + 1),
...meta,
}),
error => reject(error)
);
});
});
});
});
}
select a file from the file system of the mobile.
async selectAFile() {
this.getFileInfo()
.then(async fileMeta => {
//get the upload
const uploadUrl = await this.getUploadUrl(fileMeta);
const response: Promise < any > = this.uploadFile(
fileMeta,
uploadUrl
);
response
.then(function(success) {
//upload success message
})
.catch(function(error) {
//upload error message
});
})
.catch(error => {
//something wrong with getting file infomation
});
}
uploading selected file.
This depends on your backend implementation. This is how to use File Transfer to upload a file.
uploadFile(fileMeta, uploadUrl) {
const options: FileUploadOptions = {
fileKey: 'file',
fileName: fileMeta.fileNameFromPath,
headers: {
'Content-Length': fileMeta.size,
'Content-Type': fileMeta.type,
},
httpMethod: 'PUT',
mimeType: fileMeta.type,
};
const fileTransfer: FileTransferObject = this.transfer.create();
return fileTransfer.upload(file.path, uploadUrl, options);
}
hope it helps. :)

Node.js binary to PDF

I have got a express server, which creates a pdf file.
I am trying to send this file to the client:
const fs = require('fs');
function download(req, res) {
var filePath = '/../../myPdf.pdf';
fs.readFile(__dirname + filePath, function(err, data) {
if (err) throw new Error(err);
console.log('yeyy, no errors :)');
if (!data) throw new Error('Expected data, but got', data);
console.log('got data', data);
res.contentType('application/pdf');
res.send(data);
});
}
On the client I want to download it:
_handleDownloadAll = async () => {
console.log('handle download all');
const response = await request.get(
`http://localhost:3000/download?accessToken=${localStorage.getItem(
'accessToken'
)}`
);
console.log(response);
};
I recieve an body.text like
%PDF-1.4↵1 0 obj↵<<↵/Title (��)↵/Creator (��)↵/Producer (��Qt 5.5.1)↵
but I can't achieve a download.
How can I create a PDF from the data OR directly download it from the server?
I've got it working:
The answer was pretty simple. I just let the browser handle the download with an html anchor tag:
server:
function download(req, res) {
const { creditor } = req.query;
const filePath = `/../../${creditor}.pdf`;
res.download(__dirname + filePath);
}
client:
<a href{`${BASE_URL}?accessToken=${accessToken}&creditor=${creditorId}`} download>Download</a>

The result is the string of the binary. We use base 64 to convert from binary to pdf
var buffer = Buffer.from(result['textBinary'], 'base64')
fs.writeFileSync('/path/to/my/file.pdf', buffer)

You can prompt the browser to download the file by setting the correct content-disposition header:
res.setHeader('Content-disposition', 'attachment; filename=myfile.pdf');

readFile returns a Buffer which is a wrapper around bytes. You're sending Buffer back to the client which is logging them to the console.
The body.text you see is to be expected.
You will need to write these bytes to a file using fs.writeFile or similar. Here's an example:
_handleDownloadAll = async () => {
console.log('handle download all');
const response = await request.get(
`http://localhost:3000/download?accessToken=${localStorage.getItem(
'accessToken'
)}`
);
// load your response data into a Buffer
let buffer = Buffer.from(response.body.text)
// open the file in writing mode
fs.open('/path/to/my/file.pdf', 'w', function(err, fd) {
if (err) {
throw 'could not open file: ' + err;
}
// write the contents of the buffer
fs.write(fd, buffer, 0, buffer.length, null, function(err) {
if (err) {
throw 'error writing file: ' + err;
}
fs.close(fd, function() {
console.log('file written successfully');
});
});
});
};
You may need to experiment with the buffer encoding, it defaults to utf8.
Read this!
The other option you may want to consider is generating the PDF on the server and simply sending the client a link to where it can download this.