小编Paw*_*ski的帖子

我想问一下我的订阅方法。我想从 firebase 中获取我的对象（员工）并对我的对象进行大量操作，例如平均工资、平均缺勤天数……在我看来，这看起来太可怕了。我的服务无效：

 getEmployees(): Observable<Employee[]> {
    return this.db.list<Employee>(this.Api_url).snapshotChanges()
      .pipe(map(response => response.map(car => this.assignKey(car))));
  }

还有我的 ngOnInit：

  ngOnInit() {

    this.subscribtion = this.mainservice.getEmployees().subscribe((emps)=> {
      this.employees = emps;
      this.workersdatas = [];
      this.educationdatas = [];
      this.checkavaragesalaries(emps);
      this.countMonthAbsences(emps, 1);
      this.countMonthSalaries(emps, 1);
      this.departments.forEach((one)=> {
        const dep = emps.filter(on => on.department.includes(one) && this.FilterEmployees(on)).length;
        this.workersdatas.push({name: one, value: dep});
      });

      this.educations.forEach((one)=> {
        const edu = emps.filter(on => on.education.includes(one)).length;
        this.educationdatas.push({name: one, value: edu});
      });

      const mynumb =this.educationdatas.map(on => on.value);
      this.mosteducation = this.educationdatas.filter(one => one.value === Math.max(...mynumb))[0].name;
    }); }

我应该在 ngOnDestroy …