How to convert Observable<any> to array[]

Question

I have following method in typescript, I need to bind to angular grid

CountryService

GetCountries()  {
  return this.http.get(`http://services.groupkt.com/country/get/all`)
    .map((res:Response) => <CountryData[]>res.json().RestResponse["result"]);
}

GridComponent

  template: `
        <ag-grid-ng2 style="width: 100%" #agGrid class="ag-material"
                    rowHeight="50"
                    [gridOptions]="myGridOptions" 
                     >
            </ag-grid-ng2>
        `,

  this.myGridOptions.rowData= this.CountryService.GetCountries();

CountryData

export class CountryData{
  name: string;
  alpha2_code: string;
  alpha3_code: string;
}

But GetCoutries will return Observable of any, unable to bind to rowData?

How to convert Observable to CountryData[] in typescript ?

you find JSON data here: http://services.groupkt.com/country/get/all

Answer 1

You will need to subscribe to your observables:

this.CountryService.GetCountries()
    .subscribe(countries => {
        this.myGridOptions.rowData = countries as CountryData[]
    })

And, in your html, wherever needed, you can pass the async pipe to it.

Answer 2

Using HttpClient (Http's replacement) in Angular 4.3+, the entire mapping/casting process is made simpler/eliminated.

Using your CountryData class, you would define a service method like this:

getCountries()  {
  return this.httpClient.get<CountryData[]>('http://theUrl.com/all');
}

Then when you need it, define an array like this:

countries:CountryData[] = [];

and subscribe to it like this:

this.countryService.getCountries().subscribe(countries => this.countries = countries);

A complete setup answer is posted here also.

Answer 3

This should work:

GetCountries():Observable<CountryData[]>  {
  return this.http.get(`http://services.groupkt.com/country/get/all`)
    .map((res:Response) => <CountryData[]>res.json());
}

For this to work you will need to import the following:

import 'rxjs/add/operator/map'