How to save a single document field in cloud firestore into a local variable in flutter?

Question

I would like to save a single document field into a local variable, but I am not able to do that. Here is my code:

void getPostsData() async{
    List<Widget> listItems = [];
    String _title;
    String _content;
    final QuerySnapshot result = await Firestore.instance.collection('Social_Posts').getDocuments();
    final List<DocumentSnapshot> documents = result.documents;
    documents.forEach((data){
      listItems.add(
          GestureDetector(
            onTap: () async{
              print(data["postTitle"]);
              print(data["postContent"]);
              setState(() {
               data["postTitle"] == _title;
               data["postContent"] == _content;
              });
              print(_title);
            },
       )
    );
      }

Whenever I try to print out "_title" or "_content", I get null. Why is that happening and how do I fix this?

Answer 1

You should probably change

       data["postTitle"] == _title;
       data["postContent"] == _content;

to:

       _title = data["postTitle"];
      _content= data["postContent"];