How to download file directly in node response in react? - javascript

How do I download the document I receive in return in react?
Here is the my node.js app. fetchContracts is a function which getting data from mongodb then ganere a excel file by using json2xls npm package.
Its returns as like this:
const xls = json2xls(contracts);
return xls;
If tying to write file fs.writeFileSync(path.join(__dirname, filename), xls, 'binary'); generating successfully xlsx file in the server.
But I need to send the file to the server without writing file. For this, I made some experiments that you can see below.
export const EXPORT_EXCEL: SessionedAsyncControllerType = async (req: SessionedRequest, res: Response) => {
const fileName = 'hello_world.xlsx'
const fileType = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
const xls = await fetchContracts({}, "fileName.xlsx")
const fileData = xls;
res.writeHead(200, {
'Content-Disposition': `attachment; filename="${fileName}"`,
'Content-Type': fileType,
})
const download = Buffer.from(fileData, 'base64')
res.end(download)
}
I getting response like this.
But i don't know how can i download the response file in react?
In react side:
return api.get(`api/excel`).then((response: any) => {
console.log(response);
})
I just log into console. How can i download directly file which coming node response in react.js?

Try this
return api.get(`api/excel`).then((response: any) => {
const outputFilename = `${Date.now()}.xlsx`;
// If you want to download file automatically using link attribute.
const url = URL.createObjectURL(new Blob([response.data]));
const link = document.createElement('a');
link.href = url;
link.setAttribute('download', outputFilename);
link.click();
})

Related

Unable to read file from S3 url

I have excel file stored in S3 bucket fro where I am storing the file url inside mongodb.I
want to read data from this excel file and transform into JSON.So for that I am XLSX package but it is not reading the file as I am passing the file url inside the method,
Below is my code:
try {
const data = await productSchema.findOne({ report_id: reportId });
if (data) {
console.log(data.me_url); //I am getting the file url
const file = xlsx.readFile(data.me_url);
const sheetNames = file.SheetNames;
const totalSheets = sheetNames.length;
console.log(sheetNames);
console.log(totalSheets);
}
}
catch (err) {
return err;
}
Any idea why it is not reading the file or anyhthing I have missed.

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;

Uploading an mp3 to Firebase Storage with React Native Expo

I am attempting to upload an mp3 to firebase storage using expo and react native. So far I've got the file into firebase storage, but it's only 9bytes large, so I'm doing something wrong. I've attempted this with blob as shown below with no success.
Here is a screenshot of the firebase storage folder showing the file uploaded but not the data of said file:
Any help is greatly appreciated, I feel like I'm missing a step to actually upload the data along with the file.
export default function SongPicker() {
const [song, setSong] = useState(null);
//Get current user through authentication
const user = auth.currentUser;
const pickDocument = async () => {
let result = await DocumentPicker.getDocumentAsync({});
// Fetch the photo with it's local URI
const response = fetch(result.uri);
alert(result.uri);
console.log(result);
const file = new Blob(
[response.value], {
type: 'audio/mpeg'
});
console.log('do we see this?');
try {
//Create the file reference
const storage = getStorage();
const storageRef = ref(storage, `songs/${user.uid}/${result.name}`);
// Upload Blob file to Firebase
const snapshot = uploadBytes(storageRef, file, 'blob').then((snapshot) => {
console.log('Uploaded a song to firebase storage!');
});
setSong(result.uri);
} catch (error) {
console.log(error);
}
}
The fetch() returns a Promise so you should add an await for that as well.
const response = await fetch(result.uri);
Then try using blob() method on the Response:
const file = await response.blob()
The third param in uploadBytes should be upload metadata object but you can skip that here:
const snapshot = await uploadBytes(storageRef, file).

How to convert base64 image data to data URL in react native?

I am using react-native-signature-canvas which returns the signature as a base64 image string. I want to send it to the API and before that, I want to convert it to the data URL. Can anyone help me? Also, I don't want to store the file/image to the local storage..just wanna convert it to the DataUrl and send it to the API.
Try below code to convert base64ImageString to DataUrl
const DataUrl = `data:image/png;base64,${base64ImageString}`;
Ref : Upload base64 Image to Firebase React native
install react-native-fs
import RNFS from 'react-native-fs';
import {Platform} from 'react-native';
const createTempImage = async base64String => {
try {
let base64 = base64String.replace('data:image/png;base64,', '');
const fileName = `${Date.now()}.png`;
// creates a file in temporary directory to delete later
const path = `${RNFS.TemporaryDirectoryPath}/${fileName}`;
await RNFS.writeFile(path, base64, 'base64');
const image = {
uri: Platform.OS == 'ios'? path: 'file://' + path,
name: fileName,
type: 'image/png',
};
return image
} catch (error) {
console.log(error);
}
};
You can delete the file when the request done

How to download entire folder from Firebase Storage?

I want to download an entire folder from Firebase storage. I can download single files using DownloadURL as follows, but it does not work for folders.
var storageRef = firebase.storage().ref();
// Create a reference to the file we want to download
var starsRef = storageRef.child(path);
// Get the download URL
starsRef.getDownloadURL().then(function(url) {
// Insert url into an <img> tag to "download"
ImageUrl = url;
console.log(ImageUrl);
}).catch(function(error) {
switch (error.code) {
case 'storage/object_not_found':
// File doesn't exist
break;
case 'storage/unauthorized':
// User doesn't have permission to access the object
break;
case 'storage/canceled':
// User canceled the upload
break;
case 'storage/unknown':
// Unknown error occurred, inspect the server response
break;
}
});
How to download entire folder from Firebase?
You can use gsutil to download the whole storage bucket
gsutil -m cp -R gs://<bucket_name> .
There is no API in Firebase Storage to download all files in a folder. You will have to download the files one by one, or create a zip file that contains all the files.
As Lahiru's answer shows it can be accomplished with gsutils, but that's a server-side operation - not something you'd run in your client-side application.
Related:
How to get a list of all files in Cloud Storage in a Firebase app?
Command gustil for Windows !!!
gsutil cp -r gs://<bucket_name>.appspot.com/OBJECT_NAME "D:\path"
Use Cloud tools for PowerShell
REF for install windows >> https://cloud.google.com/storage/docs/gsutil_install
You can download the folder by creating a zip file of it.
Here is a sample function:
import JSZip from 'jszip';
import { saveAs } from 'file-saver';
import {
getStorage,
listAll,
ref,
getDownloadURL,
getMetadata,
} from 'firebase/storage';
import { auth } from '../../Firebase';
export const downloadFolderAsZip = async () => {
const jszip = new JSZip();
const storage = getStorage();
const folderRef = ref(
storage,
'images'
);
const folder = await listAll(folderRef);
const promises = folder.items
.map(async (item) => {
const file = await getMetadata(item);
const fileRef = ref(storage, item.fullPath);
const fileBlob = await getDownloadURL(fileRef).then((url) => {
return fetch(url).then((response) => response.blob());
});
jszip.file(file.name, fileBlob);
})
.reduce((acc, curr) => acc.then(() => curr), Promise.resolve());
await promises;
const blob = await jszip.generateAsync({ type: 'blob' });
saveAs(blob, 'download.zip');
};
For a recursive solution that includes subfolders in the zip file, see the following sample. You'll instantiate a jszip object, await promises from a function that zips files and traverses the directories, then save the zip. If the content is a file ("item"), it is zipped into the jszip object. If it is a folder ("prefix"), the function is called again with a new subpath, passing in the same jszip object. For further improvement, you may want to get contents with list and pagination if your contents are too many for listAll, since listAll limits retrievals.
import JSZip from 'jszip';
import { saveAs } from 'file-saver';
import {
getStorage, ref, getBlob, listAll,
} from "firebase/storage";
const addFilesFromDirectoryToZip = async (directoryPath = "", zip) => {
const storage = getStorage();
const directoryContentsRef = ref(
storage,
directoryPath
);
const directoryContents = await listAll(directoryContentsRef);
for (const file of directoryContents.items) {
const fileRef = ref(storage, file.fullPath);
const fileBlob = await getBlob(fileRef)
zip.file(file.fullPath, fileBlob);
}
for (const folder of directoryContents.prefixes) {
await addFilesFromDirectoryToZip(folder.fullPath, zip);
};
};
export const downloadFolderAsZip = async (directoryPath = "") => {
const zip = new JSZip();
await addFilesFromDirectoryToZip(directoryPath, zip);
const blob = await zip.generateAsync({ type: "blob" });
const name = directoryPath.split('/').pop();
saveAs(blob, name);
};

Categories