stream builder

StreamBuilder(
        stream: commentsStream,
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return Container();
          }

          return GestureDetector(
            onTap: () {
              FocusScope.of(context).unfocus();
            },
            child: snapshot.data.documents.length != 0
                ? ListView.builder(
                    itemCount: snapshot.data.documents.length,
                    physics: AlwaysScrollableScrollPhysics(),
                    controller: _scrollController,
                    reverse: true,
                    itemBuilder: (context, index) {
                      return CommentsTile(
                        message: snapshot.data.documents[index].data["message"],
                        isAuthor: int.parse(snapshot
                                    .data.documents[index].data["isAuthor"]
                                    .toString()
                                    .trim()) ==
                                0
                            ? false
                            : true,
                        value: int.parse(snapshot
                            .data.documents[index].data["isAuthor"]
                            .toString()
                            .trim()),
                        name: snapshot.data.documents[index].data["username"],
                        date: formatDate(
                            snapshot.data.documents[index].data["time"]),
                      );
                    })
                : Center(
                    child: Text(
                      "No comments",
                      style: TextStyle(
                          color: Colors.black,
                          fontSize: 15,
                          fontStyle: FontStyle.italic),
                    ),
                  ),
          );
        },
      );