与Http请求的角度APP_INITIALIZER

Question

I'm trying to incorporate APP_INITIALIZER in my angular project to make a http request to get a list of user permissions for display. However the http request inside the function its calling doesn't appear to be firing.

providers: [
    PermissionService,
    { provide: APP_INITIALIZER, useFactory: (permissionServiceFactory: PermissionService) => () => permissionServiceFactory.getPermissions(), deps: [PermissionService], multi: true },
],

getPermissions() {
    return this.http.get(this.url).pipe(
         map(this.extractPermissions),
         catchError(this.handleError)
    )
}

I can see getPermissions being called and I've tried putting it inside a setTimeout but nothing seems to be working. Is this a issue with APP_INITIALIZER? It seems rather simple I don't know what I would be doing wrong.

Answer 1

getPermissions() needs to return a promise

getPermissions(): Promise<any> {
   const temp = return this.http.get(this.url).pipe(
         map(this.extractPermissions),
         catchError(this.handleError)
    );
   return temp;
}