Develop Reference

Using ExcelJS, how to read data from excel file using URL?

I have excel file upload in cloud. Using node js when front end pass URL i need to read data from excel file. Below is my code,
var workbook = new ExcelJS.Workbook();
workbook.xlsx.load('https://file-examples.com/wp-content/uploads/2017/02/file_example_XLSX_10.xlsx')
.then(function() {
var worksheet = workbook.getWorksheet(sheet);
worksheet.eachRow({ includeEmpty: true }, function(row, rowNumber) {
console.log("Row " + rowNumber + " = " + JSON.stringify(row.values));
});
});
But I'm getting this error,
Can't find end of central directory : is this a zip file ? If it is, see https://stuk.github.io/jszip/documentation/howto/read_zip.html
Can someone help me to fix this?

Fixed using the below code.
const axios = require("axios");
const XLSX = require("xlsx");
const jsontoxml = require("jsontoxml");
async function testAxiosXlsx(url) {
const options = {
url,
responseType: "arraybuffer"
}
let axiosResponse = await axios(options);
const workbook = XLSX.read(axiosResponse.data);
let worksheets = workbook.SheetNames.map(sheetName => {
return { sheetName, data: XLSX.utils.sheet_to_json(workbook.Sheets[sheetName]) };
});
console.log("json:\n", JSON.stringify(worksheets), "\n\n");
console.log("xml:\n", jsontoxml(worksheets, {}));
}
testAxiosXlsx("https://file-examples.com/wp-content/uploads/2017/02/file_example_XLSX_10.xlsx");

Look at the documentation.
The load method expects you to pass a Buffer containing Excel data.
You are passing it a string, and that string contains a URL, not Excel data.
You need to fetch the data and convert it to a buffer.

Fail to upload local CSV file with fetch() and fail to execute FileReader()

I'm trying to manipulate a local CSV file with JavaScript. My purpose is to display datas from my CSV on my website, like we were using an external API in JSON format for example.
const csvLocalFile =
"http://XXX/.../file.csv";
const openFile = async () => {
const csv = await fetch(csvLocalFile).then();
let reader = new FileReader();
reader.onload = function () {
let text = reader.result;
filecontent = text.replace("", "");
};
reader.readAsText(csv.files[0]);
};
openFile();
Chrome display this error :
TypeError: Cannot read properties of undefined (reading '0')
When I delete "[0]" from "reader.readAsText(csv.files[0])", I have this message error :
TypeError: Failed to execute 'readAsText' on 'FileReader': parameter 1 is not of type 'Blob'.

A empty .then() isn't the problem, turns out it works fine without a fn. but you should remove it regardless.
The FileReader can't read Response objects, only File & Blobs...
You say that you try to read a local file, but yet you use fetch to get a remote file, so what is it that your really trying to do? it's unclear of how to help you...
a csv isn't valid json data, so you can't use .then((res) => res.JSON())
beside res.JSON() is wrong, it should be all lowercased... res.json()
The FileReader is considered legacy so you no longer need it... use await blob.text() instead
here are two examples of how to read 1 remote file using fetch
// Simulate getting a file from eg a file input or drag and drop
const file = new File(['id,name\n10,bob'], 'file.csv', { type: 'text/csv' })
// Simulate a remote location to get the csv from
const url = URL.createObjectURL(file)
const csvLocalFile = url // http://XXX/.../file.csv
const openFile = async () => {
const response = await fetch(csvLocalFile)
const text = await response.text()
console.log(text)
}
openFile()
...and another with a actual local file selected from a user input
const fileInput = document.querySelector('#fileInput')
fileInput.onchange = async () => {
const file = fileInput.files[0]
const text = await file.text()
console.log(text)
}
// ignore code below this line...
// Create a dummy file that we can use to change the file input with...
const dummyFile = new File(['id,name\n10,bob'], 'file.csv', { type: 'text/csv' })
// Used for creating a new FileList in a round-about way
const b = new ClipboardEvent('').clipboardData || new DataTransfer()
b.items.add(dummyFile)
// simulate picking a file
fileInput.files = b.files
fileInput.onchange()
<input type="file" id="fileInput">

Downloading Image locally from GitHub Raw link using fs.writeFileSync() JS

Currently trying to download image from GitHub locally. Everything seems to work, the fetch goes through with a 200 OK response, however, I don't understand how to store image itself:
const rawGitLink = "https://raw.githubusercontent.com/cardano-foundation/CIPs/master/CIP-0001/CIP_Flow.png"
const folder = "/Folder"
const imageName = "/Test"
const imageResponse = await axios.get(rawGitLink)
fs.writeFileSync(___dirname + folder + imageName, imageResponse, (err) => {
//Error handling
}
)

Four problems had to be fixed:
Image name must include png format for this case
The response must be in the correct format as a buffer for an image
You must write the response data and not the object itself
__dirname only needs two underscores
const rawGitLink = "https://raw.githubusercontent.com/cardano-foundation/CIPs/master/CIP-0001/CIP_Flow.png"
const folder = "/Folder"
const imageName = "/Test.png"
const imageResponse = await axios.get(rawGitLink, { responseType: 'arraybuffer' });
fs.writeFileSync(__dirname + folder + imageName, imageResponse.data)

Axios returns a special object: https://github.com/axios/axios#response-schema
let {data} = await axios.get(...)
await fs.writeFile(filename, data) // you can use fs.promises instead of sync
As #Leau said you should include the extension on the filename
Another sugestion is to use the path module to create the filename:
filename = path.join(__dirname, "/Folder", "Test.png")

Is there a way to unzip a file from a url request and parse its content in node?

I want to download a zip file from a url and parse its contents in node. I do not want to save the file on disk. The zip file is a directory of csv files that I want to process. How can I approach this? The only package that has an option for unzipping from a URL is unzipper but it does not work for me. Every other package lets you unzip a file on disk by providing the path to the file but not a url.
I am downloading the file like so:
const res = await this.get(test)
But what can I do now? There are packages like AdmZip that can extract zip files but need a path as a string to a file on disk. Is there a way I can pass/ stream my res object above to the below?
var AdmZip = require('adm-zip');
// reading archives
var zip = new AdmZip("./my_file.zip");
var zipEntries = zip.getEntries(); // an array of ZipEntry records
zipEntries.forEach(function(zipEntry) {
console.log(zipEntry.toString()); // outputs zip entries information
if (zipEntry.entryName == "my_file.txt") {
console.log(zipEntry.getData().toString('utf8'));
}
});

Here's a simple example of downloading a .zip file and unzipping using adm-zip. As #anonymouze points out, you can pass a buffer to the AdmZip constructor.
const axios = require("axios");
const AdmZip = require('adm-zip');
async function get(url) {
const options = {
method: 'GET',
url: url,
responseType: "arraybuffer"
};
const { data } = await axios(options);
return data;
}
async function getAndUnZip(url) {
const zipFileBuffer = await get(url);
const zip = new AdmZip(zipFileBuffer);
const entries = zip.getEntries();
for(let entry of entries) {
const buffer = entry.getData();
console.log("File: " + entry.entryName + ", length (bytes): " + buffer.length + ", contents: " + buffer.toString("utf-8"));
}
}
getAndUnZip('https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-zip-file.zip');
In this case I'm simply using axios to download a zip file buffer, then parsing it with AdmZip.
Each entry's data can be accessed with entry.getData(), which will return a buffer.
In this case we'll see an output something like this:
File: sample.txt, length (bytes): 282, contents: I would love to try or hear the sample audio your app can produce. I do...
Here's another example, this time using node-fetch:
const fetch = require('node-fetch');
const AdmZip = require('adm-zip');
async function get(url) {
return fetch(url).then(res => res.buffer());
}
async function getAndUnZip(url) {
const zipFileBuffer = await get(url);
const zip = new AdmZip(zipFileBuffer);
const entries = zip.getEntries();
for(let entry of entries) {
const buffer = entry.getData();
console.log("File: " + entry.entryName + ", length (bytes): " + buffer.length + ", contents: " + buffer.toString("utf-8"));
}
}
getAndUnZip('https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-zip-file.zip');

Reactjs How to download file from Azure Storage Container

I am working on reactjs/typescript applications. I am trying to download some files from azure storage v2. Below is the sample path I am supposed to download files. In this path, enrichment is the container name, and the rest all are folders. I am trying to download the last modified file from reportdocument folder.
enrichment/report/SAR-1234-56/reportdocument/file1.docs
I tried something below.
#action
public async reportDownload(sarNumber: string) {
let storage = globals.getGlobals('StorageAccount03');
console.log(storage);
let containerName = globals.getGlobals('StorageAccount03ContainerName');
let marker = undefined;
let allUploadPromise: Array<Promise<unknown>> = [];
const config = {
path: `/Storage/getsastoken/?storageName=${storage}&containerName=${containerName}`,
method: "GET",
success: (url: any) => {
const containerURL: ContainerURL = new ContainerURL(
url,
StorageURL.newPipeline(new AnonymousCredential()));
const listBlobsResponse = containerURL.listBlobFlatSegment(
Aborter.none,
marker,
);
}
};
await handleRequest(config);
}
From here I am struggling to download the latest modified file from the above path.
can someone help me to fix this? Any help would be greatly appreciated. Thank you

It's better to use #azure/storage-blob library and then the code would be something like below instead of directly trying to call blob REST API like you were trying in your code which seems unnecessary reinventing the wheel. The library already does it for you. Refer this for details.
const { BlobServiceClient } = require("#azure/storage-blob");
const account = "<account name>";
const sas = "<service Shared Access Signature Token>";
const containerName = "<container name>";
const blobName = "<blob name>";
const blobServiceClient = new BlobServiceClient(`https://${account}.blob.core.windows.net${sas}`);
async function download() {
const containerClient = blobServiceClient.getContainerClient(containerName);
const blobClient = containerClient.getBlobClient(blobName);
// Get blob content from position 0 to the end
// In browsers, get downloaded data by accessing downloadBlockBlobResponse.blobBody
const downloadBlockBlobResponse = await blobClient.download();
const downloaded = await blobToString(await downloadBlockBlobResponse.blobBody);
console.log("Downloaded blob content", downloaded);
// [Browsers only] A helper method used to convert a browser Blob into string.
async function blobToString(blob) {
const fileReader = new FileReader();
return new Promise((resolve, reject) => {
fileReader.onloadend = (ev) => {
resolve(ev.target.result);
};
fileReader.onerror = reject;
fileReader.readAsText(blob);
});
}
}

The SAS token expiry bothers me.You cannot have a static SAS token that expires sooner unless we can set long expiry (user-delegation SAS token is short lived). Do we really have the capability to create the SAS token dynamically in javascript runtime? I think it's only possible in NodeJS runtime.