Flutter Firestore 如何列出我只有聊天记录的人？

Question

This is a part of my chat homepage & it lists every user in my firestore database. But I want to make it list the only people I contacted with.

Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        automaticallyImplyLeading: false,
        backgroundColor: Colors.white,
        title: Text(
          'Sohbet',
          style: TextStyle(color: primaryColor, fontWeight: FontWeight.bold),
        ),
        iconTheme: IconThemeData(
          color: Colors.black, //change your color here
        ),
        centerTitle: true,
        actions: <Widget>[
          PopupMenuButton<Choice>(
            onSelected: onItemMenuPress,
            itemBuilder: (BuildContext context) {
              return choices.map((Choice choice) {
                return PopupMenuItem<Choice>(
                    value: choice,
                    child: Row(
                      children: <Widget>[
                        Icon(
                          choice.icon,
                          color: primaryColor,
                        ),
                        Container(
                          width: 10.0,
                        ),
                        Text(
                          choice.title,
                          style: TextStyle(color: primaryColor),
                        ),
                      ],
                    ));
              }).toList();
            },
          ),
        ],
      ),
      body: WillPopScope(
        child: Stack(
          children: <Widget>[
            // List
            Container(
              child: StreamBuilder(
                stream: FirebaseFirestore.instance
                    .collection('users')
                    .limit(_limit)
                    .snapshots(),
                builder: (context, snapshot) {
                  if (!snapshot.hasData) {
                    return Center(
                      child: CircularProgressIndicator(
                        valueColor: AlwaysStoppedAnimation<Color>(themeColor),
                      ),
                    );
                  } else {
                    return ListView.builder(
                      padding: EdgeInsets.all(10.0),
                      itemBuilder: (context, index) =>
                          buildItem(context, snapshot.data.documents[index]),
                      itemCount: snapshot.data.documents.length,
                      controller: listScrollController,
                    );
                  }
                },
              ),
            ),

            // Loading
            Positioned(
              child: isLoading ? const Loading() : Container(),
            )
          ],
        ),
      ),
    );
  }

  Widget buildItem(BuildContext context, DocumentSnapshot document) {
    if (document.data()['id'] == _auth.currentUser.uid) {
      return Container();
    } else {
      return Container(
        child: FlatButton(
          child: Row(
            children: <Widget>[
              Material(
                child: document.data()['photoUrl'] != null
                    ? CachedNetworkImage(
                        placeholder: (context, url) => Container(
                          child: CircularProgressIndicator(
                            strokeWidth: 1.0,
                            valueColor:
                                AlwaysStoppedAnimation<Color>(themeColor),
                          ),
                          width: 50.0,
                          height: 50.0,
                          padding: EdgeInsets.all(15.0),
                        ),
                        imageUrl: document.data()['photoUrl'],
                        width: 50.0,
                        height: 50.0,
                        fit: BoxFit.cover,
                      )
                    : Icon(
                        Icons.account_circle,
                        size: 50.0,
                        color: greyColor,
                      ),
                borderRadius: BorderRadius.all(Radius.circular(25.0)),
                clipBehavior: Clip.hardEdge,
              ),
              Flexible(
                child: Container(
                  child: Column(
                    children: <Widget>[
                      Container(
                        child: Text(
                          '${document.data()['nickname']}',
                          style: TextStyle(color: primaryColor),
                        ),
                        alignment: Alignment.centerLeft,
                        margin: EdgeInsets.fromLTRB(10.0, 0.0, 0.0, 5.0),
                      ),
                      /*Container(
                        child: Text(
                          'About me: ${document.data()['aboutMe'] ?? 'Not available'}',
                          style: TextStyle(color: primaryColor),
                        ),
                        alignment: Alignment.centerLeft,
                        margin: EdgeInsets.fromLTRB(10.0, 0.0, 0.0, 0.0),
                      )*/
                    ],
                  ),
                  margin: EdgeInsets.only(left: 20.0),
                ),
              ),
            ],
          ),
          onPressed: () {
            Navigator.push(
                context,
                MaterialPageRoute(
                    builder: (context) => Chat(
                          peerId: document.id,
                          peerAvatar: document.data()['photoUrl'],
                        )));
          },
          color: greyColor2,
          padding: EdgeInsets.fromLTRB(25.0, 10.0, 25.0, 10.0),
          shape:
              RoundedRectangleBorder(borderRadius: BorderRadius.circular(10.0)),
        ),
        margin: EdgeInsets.only(bottom: 10.0, left: 5.0, right: 5.0),
      );
    }
  }

Pics of my firestore data paths like:

Users collection

Messages collection

An example message doc

Tried:

set({friends array}) for per user in google sign in auth function but everytime I sign in it resets that array so there is no point updating that array because it resets that friends/contacts list everytime user signs in.

Answer 1

First you need to store the friends information, you can add a simple if check after google sign in auth function that if a document exists do not create a new document that would solve your resetting problem.

Assuming you have a currentUser object with firestore document id's

final friends = (await FirebaseFirestore.instance.collection("users").doc(currentUser.id).get()).data;

Get the friends list for the current user, you can convert it to list of user ids by mapping.

stream: FirebaseFirestore.instance
                .collection('users')
                .where("id",whereIn: friendsIds)
                .limit(_limit)
                .snapshots(),

Answer 2

i know this is super late but it might be useful for future search. in every chat room(in your case it is messages), you need to create a field members which has a type of array or map. Inside that array, you need to store your id and the id of the person you are chatting with. After that, you can just query the chat rooms .where((room) => room.members.contains(//your_id)) .