问进行单个API调用并将响应存储在服务中，以便其他组件可以使用该响应，而不必进行额外的API调用

EN

getChartDetail(chartId){
   const url = 'test/someurl';
   return this.service.httpCall('get', url, null)
          .map(chart => this.processChart(chart));
}

processChart(chart) {
   const result = _.cloneDeep(chart);
   _.forEach(result.sections, (section) => {
        const subCategories= _.flatMap(section.categories, 'subCategories');
        _.assign(section, {
            subCategories,
            categories:undefined,
        });
   });
   return result;
}

ngOnInit() {
   this.chartService.getChartDetail(chartId).subscribe((chart) => {
       this.data= chart.data;
   });
}

notifyAction() {
    const chartCountries = this.chartService.getCountries();
    const chartRequests = this.chartService
                              .getChartDetail(chartId)
                              .concatMap(chart =>
                                  this.chartService.listResults(
                                      this.chart.chartType,
                                      this.chart.chartVersion,
                                  )
                               ));
    Observable.zip(chartRequests, chartCountries)
        .subscribe(([settings, countries]) =>
            this.chartScore = settings;
            this.chartEvents = countries;
        });
}

toggleButton() {
    this.chartService.getChartDetail(chartId).subscribe((chart) => {
        this.chartprofileDetail(chart);
    });
}