Angular 10 get webservice status with Await? - angular10

Question

Just before login in the user, I need to test if the WebServce respond then if the system is in maintenance. On the WebService part (core3 .net) I got 2 functions:
HeartBeat that return: return Ok("OK");
MaintenanceInfo that return Return OK("No");
I display in real time the result of the 2 tests and if no problems, I display the login panel.
I need to do these tests in sequence, I was thinking doing it with await operator.
I got a TestHelperServie class with 2 functions that return bool. But I can't find how to pass from a HTTP subscribe function to a bool result. With true if I got the OK response and false if I got a timeout or another fail HTTP.
For now I do this:
async TestHeartBeat()
{
let Response:Boolean = false;
const headers = new HttpHeaders()
.set('Content-Type','application/json');
const options = {
headers: headers,
observe: "response" as const,
responseType: "json" as const
};
await this.http.get(`${environment.apiUrl}/TestController/HeartBeat`, options)
.subscribe(res=>{
Response = true;
},
error=>{
Response = false;
})
return Respone;
}
But the function does not wait for the http response.
How can I fix this?
Sorry for my newbies question, but I came from the c# world and we use await/async a lot. I don't think I can do that the same way in angular 10.

Answer 1

You can not await on Observables, you have to convert it to promise using toPromise()
return await this.http.get(....).toPromise().then(res=> Response = true).catch(err => Response = false);

Answer 2

Use rxjs pipe, map and catchError.
async TestHeartBeat()
{
const headers = new HttpHeaders()
.set('Content-Type','application/json');
const options = {
headers: headers,
observe: "response" as const,
responseType: "json" as const
};
return await this.http.get(`${environment.apiUrl}/TestController/HeartBeat`, options)
.pipe(
map(res => true),
catchError(error => false)
).toPromise();
}
Now you can call it like the following:
if (await TestHeartBeat()) {
// Display your panel
} else {
// Service is in maintenance
}