xlsx_workbook.js

module.exports = class Workbook{
    constructor(){
        if (this instanceof Workbook) return new Workbook();
        this.SheetNames = [];
        this.Sheets = {};

        //define workbook optional object
        this.wopt = {
            bookType = 'xlsx',
            bookSST: false,
            type: 'binary'
        };
    }

    appendSheet(sheet, name){
        this.sheetNames.push(name);
        this.Sheets[name] = sheet;
    }
    toBlob(option = this.wopts) {
        // string to ArrayBuffer
        function s2ab(s) {
            var buf = new ArrayBuffer(s.length);
            var view = new Uint8Array(buf);
            for (var i = 0; i !== s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
            return buf;
        }

        var wbout = XLSX.write(this, option);
        var blob = new Blob([s2ab(wbout)], { type: 'application/octet-stream' });

        return blob;
    }

    isEmpty() {
        return !this.SheetNames.length && JSON.stringify(this.Sheets === "{}");
    }

}