检查下载是否以角度5完成

Question

我正在使用Angular 5和Angular5csv导出csv，我想检测下载的文件是否已完成下载，以便添加成功消息，如何实现？

这是我生成csv文件的代码：

downloadReport(reportName){
    this.reports = [];
    this.loadReport = true;
    this.data.getReports(rosterId,reportName)
        .subscribe((data:any)=>{
            var report = data.value.toString().replace(/['"]+/g, '').split('\n');
            for (let index = 0; index < report.length; index++) {
                this.reports[index] = report[index].split(',');
            }
            this.loadReport = false;
            new Angular5Csv(this.reports,reportName.replace("_",' '));
            this.logger.success("Success","Downloaded report successfully."); // Add success message here after download
        },()=>{
            this.logger.error("Error","An error occured while processing your request.");
            this.loadReport = false;
        });
}