相当肯定的是，我只是完全想多了，或者从一个不合逻辑的Angular 来处理它。
我把我的逻辑从我的用户界面中分离出来，按钮按下调用一个位于userModel中的方法，该方法有一个更改通知符（通过一个提供程序传递到MyApp中）。我试图实现firebase，但从未直接从用户界面调用firebase（总是在用户界面代码中有请求，从未使用模型）。

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:tuple/tuple.dart';
//TODO: firebase has been installed now I need to figure out how to implement it

// TODO: add firebase read and write

class UserModel with ChangeNotifier {
  //index = session number
  List session = [];
  //create an instance of firebase (this might need to go higher in the tree)
  var db = FirebaseFirestore.instance;

  //TODO:
  //convert incoming firebase to JSON
  //convert outgoing json to firebase
  //track session

  // takes in current session data and adds the new chunk
  // already recorded (new item in list but time, breaks etc. are adding from the last one)
  // IF ADDING TO EXISTING, ALL PARAMETRS MUST BE SET

  addSessionChunk(
      {required String intention,
      int workTime = 0,
      String progress = "null",
      int breakTime = 0}) {
    session.add({
      "intention": intention,
      "workTime": workTime,
      "progress": progress,
      "breakTime": breakTime,
    });
    //firebase update?
  }

  //TODO: when returning to a previous intention, add to the numbers that were
  //TODO: currently only works for 1 call per chunk (no going back to the same intention)
  //get previous data from this intention for returning to a task (do

  //these update functions updadate the LAST CHUNK in the session

  updateChunkWorkTime({required int workTime}) {
    //this later)
    session.last["workTime"] = workTime;
  }

  //takes in inputed progress and updates the latest chunk with it
  updateChunkProgress({required String progress}) {
    session.last["progress"] = progress;
  }

  //takes inputed breaktime and updates the lastest chunk with it
  updateChunkBreakTime({required int breakTime}) {
    session.last["breakTime"] = breakTime;
  }

  //returns tuple of the total time spent working and breaking in the current session

  calculateSessionTimeTotal() {
    int totalWorkTime = 0;
    int totalBreakTime = 0;

    for (var chunk in session) {
      totalWorkTime += chunk["workTime"] as int;
      totalBreakTime += chunk["breakTime"] as int;
    }

    return Tuple2(totalWorkTime, totalBreakTime);
  }

  //firebase functions
  pushDataUp() {
    db.collection("sessions").doc().set({
      "currentSession": session,
      "total": calculateSessionTimeTotal().toString()
    });
  }

  pullDataDown() {}
}

你可以在底部看到，我开始尝试并想出了一种方法来同步本地数据状态与firebase，但我感到困惑，似乎奇怪的是，用户发送他们的数据到firebase，然后回到模型，已经持有的数据？
本地模型和云数据库交互的最佳方法是什么？任何正确方向的指导都非常感谢。