how to print value from firestore in flutter - firebase

Question

how to print value of field.
what I have tried :
print(documents[index].data['Likes.$usersId']);
actually I need this for toggle between icons.
thanks.
Update:
Widget build(BuildContext context) {
return Container(
child: StreamBuilder<QuerySnapshot>(
stream: UserManagement().getPostsStream(),
builder: (_, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
} else {
final List<DocumentSnapshot> documents = snapshot.data.documents;
return ListView.builder(
itemCount: documents.length,
itemBuilder: (_, index) {
return Card(
elevation: 4,
child: Padding(
padding: EdgeInsets.only(left: 10.0, top: 10),
child: InkWell(
onTap: () => navigateToDetail(
documents[index],
documents[index].data["Userid"],
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisSize: MainAxisSize.min,
children: <Widget>[
new Row(
children: <Widget>[
Container(
width: 45,
height: 45,
decoration: BoxDecoration(
image: DecorationImage(
image: NetworkImage(
documents[index].data["User Pic"]),
fit: BoxFit.cover,
),
borderRadius: BorderRadius.all(
Radius.circular(50.5)),
),
),
Padding(
padding: EdgeInsets.only(left: 15),
child: Text(
documents[index].data["Name"],
style: TextStyle(
fontWeight: FontWeight.w600,
fontSize: 18),
),
),
],
),
Padding(
padding: EdgeInsets.only(left: 60, bottom: 10),
child: Text(
DateFormat.yMMMd().add_jm().format(
DateTime.parse(documents[index]
.data["Creation Time"]
.toDate()
.toString())),
style: TextStyle(
color: Colors.black38, fontSize: 12),
),
),
Flexible(
child: Padding(
padding: EdgeInsets.only(left: 75, right: 15),
child: Text(
documents[index].data["Description"],
style: TextStyle(fontSize: 16),
),
),
),
Padding(
padding: EdgeInsets.only(
left: 75, top: 15, bottom: 8),
child: Text(
documents.length.toString() +
"Files uploaded",
style: TextStyle(
color: Colors.blueAccent,
fontSize: 14,
fontStyle: FontStyle.italic),
),
),
Divider(),
new Row(
children: <Widget>[
Expanded(
child: Row(
children: <Widget>[
IconButton(
onPressed: () {
print(documents[index].data['Likes.$usersId']);
},
icon: documents[index].data['$usersId'] == true ? Icon(Icons.favorite,
color: Colors.redAccent,
size: 23.0) : Icon(Icons.favorite_border,
color: Colors.redAccent,
size: 23.0)
),
/*Text(documents[index].data['Likes'].length.toString()),*/
],
),
),
Expanded(
child: IconButton(
onPressed: () {
navigateToDetail(documents[index],
documents[index].data["Userid"],);
},
icon: Icon(
Icons.chat_bubble_outline,
color: Colors.blue,
size: 23.0,
),
),
),
Expanded(
child: IconButton(
onPressed: () {},
icon: Icon(
Icons.near_me,
color: Colors.blue,
size: 23.0,
),
),
),
],
),
],
),
),
),
);
});
}
}),
);
}
This is to get Posts :
Stream<QuerySnapshot> getPostsStream() {
return Firestore.instance.collection("Posts").orderBy(
"Creation Time", descending: true).snapshots();
}

Answer 1

Change this:
print(documents[index].data['Likes.$usersId']);
into this:
print(documents[index].data['Likes'][usersId]);