snapshot.data.docs.length not working on flutter

Question

I make some listview and it have likes and comments section. I want to show how many likes and comments that post had. The like section works by displaying the number of users who like it, i try to show it with snapshot.data.docs.length.toString() from firestore but when i try to show how many comments with same code as like section it not working and only get 0.

this is inside comments field

Padding(
    padding: const EdgeInsets.only(top: 8),
    child: Padding(
      padding: const EdgeInsets.only(left: 15),
      child: Row(
        mainAxisAlignment:
            MainAxisAlignment.spaceEvenly,
        children: [
          Container(
            width: 80.0,
            child: Row(
              mainAxisAlignment:
                  MainAxisAlignment.start,
              children: [
                GestureDetector(
                  onLongPress: () {
                    Provider.of<PostFunction>(context,
                            listen: false)
                        .showLikes(
                            context,
                            documentSnapshot
                                .data()['title']);
                  },
                  onTap: () {
                    print('Adding like...');
                    Provider.of<PostFunction>(context,
                            listen: false)
                        .addLike(
                            context,
                            documentSnapshot
                                .data()['title'],
                            Provider.of<AuthenticationService>(
                                    context,
                                    listen: false)
                                .getUserUid);
                  },
                  child: Icon(
                    FontAwesomeIcons.arrowAltCircleUp,
                    color: kGreyColor,
                    size: 18.0,
                  ),
                ),
                StreamBuilder<QuerySnapshot>(
                    stream: FirebaseFirestore.instance
                        .collection('posts')
                        .doc(documentSnapshot
                            .data()['title'])
                        .collection('likes')
                        .snapshots(),
                    builder: (context, snapshot) {
                      if (snapshot.connectionState ==
                          ConnectionState.waiting) {
                        return Center(
                            child:
                                CircularProgressIndicator());
                      } else {
                        return Padding(
                          padding:
                              const EdgeInsets.only(
                                  left: 8.0),
                          child: RichText(
                            text: TextSpan(
                                text: snapshot
                                    .data.docs.length
                                    .toString(),
                                style: GoogleFonts
                                    .openSans(
                                        color:
                                            kGreyColor,
                                        fontSize: 16.0),
                                children: <TextSpan>[
                                  TextSpan(
                                      text: ' votes',
                                      style: GoogleFonts
                                          .openSans(
                                        color:
                                            kGreyColor,
                                        fontSize: 16.0,
                                      )),
                                ]),
                          ),
                        );
                      }
                    })
              ],
            ),
          ),
          SizedBox(width: 20),
          Container(
            width: 150.0,
            child: Row(
              mainAxisAlignment:
                  MainAxisAlignment.start,
              children: [
                GestureDetector(
                  onTap: () {
                    Provider.of<PostFunction>(context,
                            listen: false)
                        .showComments(
                            context,
                            documentSnapshot,
                            documentSnapshot
                                .data()['title']);
                  },
                  child: Icon(
                    FontAwesomeIcons.solidComments,
                    color: kGreyColor,
                    size: 16.0,
                  ),
                ),
                StreamBuilder<QuerySnapshot>(
                    stream: FirebaseFirestore.instance
                        .collection(' posts')
                        .doc(documentSnapshot
                            .data()['title'])
                        .collection('comments')
                        .snapshots(),
                    builder: (context, snapshot) {
                      if (snapshot.connectionState ==
                          ConnectionState.waiting) {
                        return Center(
                            child:
                                CircularProgressIndicator());
                      } else {
                        return Padding(
                          padding:
                              const EdgeInsets.only(
                                  left: 8.0),
                          child: Text(
                            snapshot.data.docs.length
                                .toString(),
                            style: GoogleFonts.openSans(
                                color: kGreyColor,
                                fontSize: 16.0),
                          ),
                        );
                      }
                    }),
              ],
            ),
          ),
          Spacer(),
          Provider.of<AuthenticationService>(context,
                          listen: false)
                      .getUserUid ==
                  documentSnapshot.data()['useruid']
              ? IconButton(
                  icon: Icon(EvaIcons.moreVertical,
                      color: kGreyColor, size: 16),
                  onPressed: () {
                    Provider.of<PostFunction>(context,
                            listen: false)
                        .showPostOptions(
                            context,
                            documentSnapshot
                                .data()['title']);
                  })
              : Container(width: 0.0, height: 0.0)
        ],
      ),
    ),
  ),

Answer 1

Replace.collection(' posts')

with.collection('posts')

in the “comments” section of the Streambuilder.

Your stream data is coming as empty as the database cannot find a collection with name (“ posts”). So when you try to show how many comments the post had with the same code as the “likes” section it is not working and only getting 0 each time.

Answer 2

just declare the dataType of builder's arguments..i mean, builder:(BuildContext context,AsyncSnapshot snapShot). check the image

Answer 3

Could you please try this one?

StreamBuilder(
  stream: firestoreDB,
  builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
    if (!snapshot.hasData) {
      return Center(child: CircularProgressIndicator());
    }
    return ListView.builder(
      itemCount: snapshot.data!.size,
      itemBuilder: (context, index) {
        return Card(
          child: ListTile(
            title: Text(snapshot.data!.docs[index]['name']),
            subtitle: Text(snapshot.data!.docs[index]['description']),
          ),
        );
      },
    );
  },
),