I'm creating a webpage that has to download a file in CSV format. The REST API returns the file.
I get an error while accessing the API. I guess that is because the file is getting converted to JSON. How can I get it from the back end and handle it?
service.ts
return this.http.get(URL); You can use file-saver
import * as FileSaver from 'file-saver';
this.http.post(url, resource, { responseType: 'blob' }) .subscribe((resp: any) => { FileSaver.saveAs(resp, `filename.csv`) }); 
To convert octet-stream to any required data type.
I had a similar situation where i converted OCTET-STREAM into pdf.
Slight difference, might be helpful for others, I received json response and octet-stream Array was a field in that json response.
In this case, replace .pdf by .csv
octet_array is the array of octet values.
let arr = new Uint8Array(octet_array); let downloadLink = document.createElement('a'); let b = new Blob([arr], { type: 'application/octet-stream' }) downloadLink.href = window.URL.createObjectURL(b); downloadLink.setAttribute('download', "prescription.pdf"); document.body.appendChild(downloadLink); downloadLink.click(); downloadLink.parentNode.removeChild(downloadLink); 