Unable to generate excel file from XLSX in ionic - ios

Question

I am creating excel file from user data but unfortunately its not generating file and even don't know what is the error so I can at-least try to solve that error.
Specially this issue occur in iOS platform only.
Please find below code to generate excel file:
public createXSLX(): Promise<any> {
return new Promise((resolve) => {
let sheet = XLSX.utils.json_to_sheet(this.data);
let wb = {
SheetNames: ["export"],
Sheets: {
"export": sheet
}
};
let wbout = XLSX.write(wb, {
bookType: 'xlsx',
bookSST: false,
type: 'binary'
});
function s2ab(s) {
let buf = new ArrayBuffer(s.length);
let view = new Uint8Array(buf);
for (let i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
return buf;
}
let blob = new Blob([s2ab(wbout)], { type: 'application/octet-stream' });
resolve(blob);
});
}
This above function works very well in android but in iOS its not generation file from provided data.
How I call above function code :
onExportNew = function (toEmail) {
this.createXSLX().then((xclBlob) => {
let time = new Date().getTime();
let fileName: string = "roster_" + time + ".xlsx";
var fs = ''
if (this.platform.is('ios')){
fs = this.file.documentsDirectory;
}else{
fs = this.file.externalDataDirectory;
}
console.log("File Path:- ",fs)
this.file.writeFile(fs, fileName, xclBlob, true).then(() => {
let fp = fs + fileName;
let email = {
// to: 'lmahajan#cisco.com',
// cc: 'erika#mustermann.de',
// bcc: ['john#doe.com', 'jane#doe.com'],
to: toEmail,
attachments: [fp],
subject: 'Roster Excel File',
body: '<h1>PFA</h1>',
isHtml: true
};
this.emailComposer.open(email).then(() => {
this.showDone = true;
}).catch(() => {
let toast = this.toastCtrl.create({
message: 'Could not open email composer',
duration: 3000
});
toast.present();
});
}).catch(() => {
this.displayAlert('Error', 'error creating file at: ' + fs);
});
}).catch(() => {
console.log("Excel file creation error");
});
}
Guide me if missing anything in above code.
Thanks in advance!