Flutter pass settings.arguments to MaterialPageRoute

Question

I use a function to perform all my routing. I now need to pass some arguments to CustomerDeskSearchResultsView and I do following:

Route<dynamic> generateRoute(RouteSettings settings) {
  final args = settings.arguments;
  switch (settings.name) {
    case homeViewRoute:
      return MaterialPageRoute(builder: (context) => const HomeView());
    case privateKeyViewRoute:
      return MaterialPageRoute(builder: (context) => const ScanPrivateKeyView());
    case userProfileViewRoute:
      return MaterialPageRoute(builder: (context) => const ProfileView());
    case userTasViewRoute:
      return MaterialPageRoute(builder: (context) => const TasView());
    case aboutViewRoute:
      return MaterialPageRoute(builder: (context) => const AboutView());
    case customerDeskViewRoute:
      return MaterialPageRoute(builder: (context) => const CustomerDeskSelectView());
    case customerDeskSearchResultsViewRoute:
      return MaterialPageRoute(builder: (context) => 
  CustomerDeskSearchResultsView(searchType: '', searchValue: ''));
    default:
      return MaterialPageRoute(builder: (context) => const Error404Screen());
  }
}

The passed arguments are searchType and searchValue. How to retrieve this from settings.arguments? args['searchType'] and args['searchvalue'] does not work.

Or am I doing this completely wrong?

score 1 · Answer 1 · answered Jul 14 '22 at 21:14

1

Maybe the best if you create a data class that holds the values:

class SearchTypeAndValueData {
   String searchType;
   String searchValue;

   SearchTypeAndValueData({required this.searchType, required this.searchValue})
}

Then you can have this data object as:

SearchTypeAndValueData data = settings.arguments as SearchTypeAndValueData;

Another way without using an extra class like that, arguments can be anything. In your case it might be a list so you can do this:

List<dynamic> arguments = settings.arguments as List<dynamic>;

But in this case you need to know on which index what data you can find, then pass it to your class:

CustomerDeskSearchResultsView(searchType: arguments[0], searchValue: arguments[1]));

Obivously you also can pass your data as a map. Then you have to convert the settings.arguments to a map.

Then you will be able to retrieve them like this:

arguments['searchType'] and arguments['searchvalue']

answered Jul 14 '22 at 21:14

stacktrace2234

1,172
1
12
22

I opted for the Class holding the variables and I have no more errors, But launching the app now, throws an exception like : type 'Null' is not a subtype of type 'SearchTypeAndValueData' in type cast – cwhisperer Jul 15 '22 at 04:27
Then you call that page with no arguments given to the routing. – stacktrace2234 Jul 15 '22 at 12:44
I understand but the error occurs when launching the app, immediately after the splashscreen. The sceen is not yet called. – cwhisperer Jul 15 '22 at 17:10
Found the answer [here](https://stackoverflow.com/questions/66522828/a-value-of-type-object-cant-be-assigned-to-a-variable-of-type-mapdynamic) – cwhisperer Jul 18 '22 at 05:20

score 0 · Answer 2 · answered Jul 14 '22 at 21:02

0

This way you are passing the values to the Constructor not to the arguments, so you can easily use them inside the screen because they are already defined as properties (variables) in the class.

answered Jul 14 '22 at 21:02

Moaz El-sawaf

2,306
1
16
33

Yes correct. But the question is how to pass the variables to the Constructor. – cwhisperer Jul 15 '22 at 05:34
I'm sorry but the question is not clear. – Moaz El-sawaf Jul 15 '22 at 11:13

Flutter pass settings.arguments to MaterialPageRoute

2 Answers2