Flutter How to search a spesific map inside of list? - list

Question

I have 3 selectable item on my UI.
I created these with ListViewBuilder. My goal is upload the selectedItem's to Firebase. Anyway, in example;
List<Map<String?, dynamic>> selectedItems = List.empty(growable: true);
List is gonna be like this right before uploading Firebase:
List selectedItems = [
{
'title': selectedItem[index].title,
'price': selectedItem[index].price,
},
];
This has to be my selectedItems list.
And I upload this list as Map like this:
Map<String, dynamic> updatedData = {'items': selectedItems};
This has to be like this in order to Firebase design.
First of all when the user has clicked to item I want to check selectedItems list.
Here is my code but it doesn't work at all:
if (selectedServices.contains(
[{
'title': selectedItem[index].title,
'price': selectedItem[index].price,
}])
The problem is right up here. After this check (also it's always passing because not working) I try to remove same items from selectedItems with this code:
selectedServices.removeWhere((item) => mapEquals(
item,
({
'title': selectedItem[index].title,
'price': selectedItem[index].price,
})));
But it doesn't work too because of the check always passing false. After these steps, my onPressed function working just on this else code bloc.
else
{
selectedServices.addAll([{
selectedItem[index].title:
selectedItem[index].price
}
]);}
A little summary;
.contains method not working like this. If there is another way to set list of maps, just let me learn that. This is important for me but I can't figure it out last few days.
And lastly, can you explain answer how it works for Dart ?

Answer 1

Edit: Focus of the question changed, so this answer now tries to achieve a contains like functionality for lists with complex items.
For a custom equality check a similar functionality to contains can be achieved via any:
import 'package:collection/equality.dart';
void main() {
final map1 = {
'title': 'item1',
'price': 12.34,
};
final map2 = {
'title': 'item2',
'price': 3.45,
};
final list = [map1, map2];
final test1 = list.any((item)=>MapEquality().equals(item, {
'title': 'item1',
'price': 12.34,
}));
print(test1);
final test2 = list.any((item)=>MapEquality().equals(item, {
'title': 'item3',
'price': 14.34,
}));
print(test2);
}
print is:
true
false
you could run into precision issues with doubles, though, or if you are using complex key-value pairs in your maps.

Answer 2

Don't you try to check if array contains other array in this code:
if (selectedServices.contains(
[{
'title': selectedItem[index].title,
'price': selectedItem[index].price,
}])
?
Try to check with one item in parameter-list:
if (selectedServices.contains(
{'title': selectedItem[index].title}
))