Question posted in 
I’ve studied all of the SO Similar Questions about this problem, a few were helpful, but did not directly address the saving of an xlsx file to the local Win10 downloads folder.
The xlsx file sits on a CentOS 7 server. If I use Filezilla to copy it to Win10, it’s fine.
Looking at the component code below, I am reading the xlsx from the server and getting its base64Str, which matches exactly what I used to store the file. I create a blob fine, but FileSaver, saves the Win10 file with its contents as the base64Str, instead of a an xlsx binary. Can FileSaver save binary content, or only text?
Thanks for helping!
Component Code
//INPUT DATA: docName: test.xlsx; mediaType: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet; snippet base64Str: VUVzREJCUU...FBQUFBPQ=
//NOTE: input data is from a CentOS 7 filesystem
const byteStr = atob(base64Str);
const arrayBuffer = new ArrayBuffer(byteStr.length);
const int8Array = new Uint8Array(arrayBuffer);
for (let i = 0; i < byteStr.length; i++) {
int8Array[i] = byteStr.charCodeAt(i);
}
const blob = new Blob([arrayBuffer], { type: mediaType }); //also tried type: 'application/octet-stream'
//alternate technique that produces same corrupted result
//const base64Response = await fetch(`data:` +mediaType +`;base64,${base64Str}`);
//const blob = await base64Response.blob();
fileSaver.saveAs(blob, docName); //saves to Win10 downloads folder
3
Answers
Not sure if this works , but try setting the mediaType like below :
Please try The below code. (Here in this example I have demonstrate the following 1) Input base64 string to a input text area 2) on click of download file link 3) will prompt to download the file into correct xlsx format without corrupted data).
Kindly modify the code as per your need . Example only demonstrate the file download feature.
Point to notice :
HTML code for demo only ( not mandatory for your requirement)
Happy to help further if needed. 🙂
so I used this. Might also work for anyone trying to convert a static base 64 string to xlxs file. This solutions assumes that you know the file type.
Regards