attack-change.effects.ts

@Effect()
    SetAttack$: Observable<Action> = this.actions$.pipe(
      ofType(fromAction.ActionTypes.SET_ATTACK),
      map((action: fromAction.SetAttack) => action.payload),
      exhaustMap((name: string) => this.ethSrv.setAttack(name).pipe(
            tap(result => console.log('result', result)),
            // retrieve the log information that will contain the event data.
            map(result => result.logs[0].args[0]),
            map((newName: string) => new fromAction.SetAttackSuccess(newName)),
            catchError(err => of(new fromAction.EthError(err)))
          )),

        );