Convert Firestore DocumentSnapshot to Map in Flutter

Question

I need to update a document with nested arrays in Firestore with Flutter.

So I need to get the full document into a Map, reorder the maps in the \"sections\" array,

Answer 1

Needed to simplify for purpose of example

class ItemsList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // get the course document using a stream
    Stream courseDocStream = Firestore.instance
        .collection('Test')
        .document('4b1Pzw9MEGVxtnAO8g4w')
        .snapshots();

    return StreamBuilder(
        stream: courseDocStream,
        builder: (context, AsyncSnapshot snapshot) {
          if (snapshot.connectionState == ConnectionState.active) {

            // get course document
            var courseDocument = snapshot.data.data;

            // get sections from the document
            var sections = courseDocument['sections'];

            // build list using names from sections
            return ListView.builder(
              itemCount: sections != null ? sections.length : 0,
              itemBuilder: (_, int index) {
                print(sections[index]['name']);
                return ListTile(title: Text(sections[index]['name']));
              },
            );
          } else {
            return Container();
          }
        });
  }
}

The Results