Угловой Обещание с условием

Question

Я не хочу попадать в конечную точку (getUserInfo), если у меня уже есть значение в моей переменной, я написал код, как показано ниже, но есть дублирующий код и хотел посмотреть, есть ли у кого-нибудь лучший способ написания этого :

let report;
if (this.userInfo) {
   report = {
    ReportType: reportType,
    ReportID: id,
    ReportFormat: format,
    ReportName: `${reportType}_${id}`,
    Filters: shouldNotParseFilters ? filterContent : [],
    ViewFields: columns || [],
    OrgName: this.userInfo[0].orgname,
    FullName: this.userInfo[0].fullname
  } as SavedReport;
  if (!shouldNotParseFilters) this.reportFilterService.mapReportFilters(<ReportFilterContext>filterContent, report);
  report.Filters.push({ 'maxitems': [-1] });
  this.nrcService.downloadReport(report, fileName).subscribe({ error: err => this.nrcService.handleError(err) });
}
else {
  this.nrcService.getUserInfo().then(data => {
    this.userInfo = data;
     report = {
      ReportType: reportType,
      ReportID: id,
      ReportFormat: format,
      ReportName: `${reportType}_${id}`,
      Filters: shouldNotParseFilters ? filterContent : [],
      ViewFields: columns || [],
      OrgName: data[0].orgname,
      FullName: data[0].fullname
    } as SavedReport;
    if (!shouldNotParseFilters) this.reportFilterService.mapReportFilters(<ReportFilterContext>filterContent, report);
    report.Filters.push({ 'maxitems': [-1] });
    this.nrcService.downloadReport(report, fileName).subscribe({ error: err => this.nrcService.handleError(err) });
  })
 }

Answer 1

В этом случае я бы предложил использовать async/await для решения ваших задач:

// Add `async` here 
async your_function_name () {
    ...
    let report;
    if (!this.userInfo) {
        // Waits until your user info is loaded
        this.userInfo = await this.nrcService.getUserInfo();
    }
    report = {
        ReportType: reportType,
        ReportID: id,
        ReportFormat: format,
        ReportName: `${reportType}_${id}`,
        Filters: shouldNotParseFilters ? filterContent : [],
        ViewFields: columns || [],
        OrgName: this.userInfo[0].orgname,
        FullName: this.userInfo[0].fullname
    } as SavedReport;

    if (!shouldNotParseFilters) {
        this.reportFilterService.mapReportFilters(<ReportFilterContext>filterContent, report);
    }

    report.Filters.push({ 'maxitems': [-1] });
    this.nrcService.downloadReport(report, fileName).subscribe({ error: err => this.nrcService.handleError(err) });

}

Если вы не знакомы с async/await, см. здесь ; -)

Другой вариант - использовать Обещания без async/await, но это выглядит не так хорошо:

let report;
// Create a new promise, which resolves directly
let promise = new Promise(r => r());
if (!this.userInfo) {
    // Assigns the loading promise to the promise variable
     promise = this.nrcService.getUserInfo().then(data => {
        this.userInfo = data;
    });
}
// Waits until the promise is resolved
promise.then(() => {
    report = {
        ReportType: reportType,
        ReportID: id,
        ReportFormat: format,
        ReportName: `${reportType}_${id}`,
        Filters: shouldNotParseFilters ? filterContent : [],
        ViewFields: columns || [],
        OrgName: this.userInfo[0].orgname,
        FullName: this.userInfo[0].fullname
    } as SavedReport;

    if (!shouldNotParseFilters) {
        this.reportFilterService.mapReportFilters(<ReportFilterContext>filterContent, report);
    }

    report.Filters.push({ 'maxitems': [-1] });
    this.nrcService.downloadReport(report, fileName).subscribe({ error: err => this.nrcService.handleError(err) });

});

Answer 2

Попробуйте это

async method() {
    const userInfo = await this.nrcService.getUserInfo();
    if (!!userInfo) {
        this.userInfo = userInfo;
    }
    if (!!this.userInfo) {
        report = {
            ReportType: reportType,
            ReportID: id,
            ReportFormat: format,
            ReportName: `${reportType}_${id}`,
            Filters: shouldNotParseFilters ? filterContent : [],
            ViewFields: columns || [],
            OrgName: this.userInfo[0].orgname,
            FullName: this.userInfo[0].fullname
        } as SavedReport;

        if (!shouldNotParseFilters) {
            this.reportFilterService.mapReportFilters(<ReportFilterContext>filterContent, report);
        }

        report.Filters.push({ 'maxitems': [-1] });
        this.nrcService.downloadReport(report, fileName).subscribe({ error: err => this.nrcService.handleError(err) });
    } else {
        // ...
    }
}

Answer 3

вы можете использовать async / await, что-то вроде

this.userInfo = await this.userInfo || this.nrcService.getUserInfo();
report = { ... }