typescript - Angular 4: How to read data from Excel?

Question

I am not able to get data from an Excel sheet in Angular 4. Below is my code sample.

HTML code:

<input id="my-file-selector" type="file" (change)="uploadData($event)" name="uploadExcel">

upload.component.ts:

public uploadData(event: any) : void { 
    // get data from file upload       
    let filesData = event.target.files;
    console.log(filesData[0]);
}

Answer 1

You should follow these 3 steps

step 1: import ts-xlsx refer: https://www.npmjs.com/package/ts-xlsx for installation

step 2: Using FileReader convert to arraybuffer

step 3: Reading the arraybuffer with XLSX and converting as workbook

HTML CODE

<input type="file" style="display: inline-block;" (change)="incomingfile($event)" placeholder="Upload file" accept=".xlsx">
<button type="button" class="btn btn-info" (click)="Upload()" >Upload</button>

Typescript

//import it

    import * as XLSX from 'ts-xlsx';

//inside export class

arrayBuffer:any;
file:File;
incomingfile(event) 
  {
  this.file= event.target.files[0]; 
  }

 Upload() {
      let fileReader = new FileReader();
        fileReader.onload = (e) => {
            this.arrayBuffer = fileReader.result;
            var data = new Uint8Array(this.arrayBuffer);
            var arr = new Array();
            for(var i = 0; i != data.length; ++i) arr[i] = String.fromCharCode(data[i]);
            var bstr = arr.join("");
            var workbook = XLSX.read(bstr, {type:"binary"});
            var first_sheet_name = workbook.SheetNames[0];
            var worksheet = workbook.Sheets[first_sheet_name];
            console.log(XLSX.utils.sheet_to_json(worksheet,{raw:true}));
        }
        fileReader.readAsArrayBuffer(this.file);
}