read excel file

readExcel.ts

// first: get excel file from server, with responseType: "arraybuffer"

const data = new Uint8Array(this.excelData);
const arr = new Array();
for (let i = 0; i !== data.length; ++i) {
        arr[i] = String.fromCharCode(data[i]);
}

const bstr = arr.join("");
const workbook = XLSX.read(bstr, { type: "binary" });

const first_sheet_name = workbook.SheetNames[0];
const worksheet = workbook.Sheets[first_sheet_name];

this.excelhtml = XLSX.utils.sheet_to_html(worksheet);

thanks to https://github.com/SheetJS/js-xlsx/tree/master/demos/angular2 👍