I am trying to creat a rest api which uses a third part api to get some status. I'll get the url from a excel file, for this specific case it needs to be a excel file, use them in my service to obtain the data from the third part api and save this response in the same excel file. I am already able to get the data from the third part api, but I'm failing to manage the excel through nest js. I tried to use exceljs library but it didn't work as I intended. I would like to have the return(assume it is inside a function) to be the cell value in this excel file. Could someone give me some hint in how to handle this file use inside nest js?
let Excel = require('exceljs');
let workBook = new Excel.Workbook();
workBook.xlsx.readFile('./ExcelFile/Archive.xlsx').then(function()
{
let sheet = workBook.getWorkSheet("Sheet1");
let cellValue = sheet.getRow(2).getCell(1).value;
});
return cellValue;
Since cellValue is defined inside a callback (.then(() => {}) you will need to return inside the callback.
Here however you you will face the issue that you cannot return it inside the callback. To fix this you have 2 options: Use async/await or return a promise
Async/await:
const Excel = require('exceljs');
async function ReadCell(filename) {
let workBook = new Excel.Workbook();
await workBook.xlsx.readFile(filename);
let sheet = workBook.getWorkSheet('Sheet1');
let cellValue = sheet.getRow(2).getCell(1).value;
return cellValue;
}
Promises:
const Excel = require('exceljs');
async function ReadCell(filename) {
return new Promise((resolve, reject) => {
let workBook = new Excel.Workbook();
workBook.xlsx.readFile(filename).then(() => {
let sheet = workBook.getWorkSheet('Sheet1');
let cellValue = sheet.getRow(2).getCell(1).value;
resolve(cellValue);
}).catch(err => /* Do some error handling here if you want to */ reject(err));
});
}
Keep in mind that when using promises you are going to need to use .then((result) => {/* your code here */}) when trying to get the result of your ReadCell() function.
You can find more info about promises here