Firestore Flutter 如何获取集合中所有文档及其数据的列表？

Question

I have been working to get a list of all the documents inside a firestore collection. I want to display all details of all documents inside a collection. My document tree is ask follows-

'groups' COLLECTION----->Documents w 'groupID' as reference------>'tasks' COLLECTION------>Documents w 'taskId' as reference.

Now I want to get all documents and its details inside 'tasks' collection for a particular groupID.

Future<MyTask> getCurrentTask(String groupId) async {
    MyTask retVal = MyTask();
    try {
      DocumentSnapshot _docSnapshot =
          await _firestore.collection("groups").document(groupId).collection("tasks").get();
      retVal.taskId = taskId;
      retVal.taskName = _docSnapshot.data['taskName'];
      retVal.dueTime = _docSnapshot.data['dueTime'];
      retVal.member =_docSnapshot.data['member'];
      retVal.completed = _docSnapshot.data['completed'];
  
    } catch (e) {
      print(e);
    }
    return retVal;
  }

I tried this but it doesnt work as "The method 'get' isn't defined for the type 'CollectionReference'." How to get around this please?

Answer 1

Simply do like this:

Firestore.instance.collection("groups").document(groupID).collection("task").snapshots().listen((event) {
  retVal = event.documents.map((e) => MyTask.fromJson(e.data)).toList();
});

I assume your MyTask model already have fromJson method so do it like that. And change your retVal to List: List<MyTask> retVal = []; . It will get all of your document and also listen whether there's change's on the collection.