ListTile not getting updated with Google Places API in flutter-CodePudding

I have this method which gets a suggested place through the Google Places API based on the user input.

  void getSuggestion(String input) async {
    var googlePlace = GooglePlace(AppConstants.APIBASE_GOOGLEMAPS_KEY);
    var result = await googlePlace.queryAutocomplete.get(input);
    setState(() {
      _placeList = result!.predictions!;
    });
  }

_placeList is filled properly, but it does not get updated instantly, I have to hot reload to see the changes whenever I change the query value in my TextController:

TextField(
                        onSubmitted: (value) {
                          setState(() {
                            getSuggestion(value);
                            showDialog(
                                context: context,
                                builder: ((context) {
                                  return Card(
                                    child: ListTile(
                                      title: Text(_placeList[0].description),
                                    ),
                                  );
                                }));
                          });
                        },

For example, if I search for "Miami" I get the recommendation on my listTile, but if I change it to "Madrid" it still appears "Miami" and I have to reload screen to see the change. I do not understand because I am setting the state in my method.

CodePudding user response：

getSuggestion is an asynchronous function. In other words, in the following code snippet:

getSuggestion(value);
showDialog(
  context: context,
  ...

After invoking getSuggestion, it does not wait the function to finish before showing the dialog. In other words, when the dialog is shown, maybe the previous function hasn't completed yet, so that _placeList is not updated yet.

Firstly, it is a better idea to get rid of setState within getSuggestion as it is redundant to do it twice.

Secondly, in the onSubmitted lambda, make the anonymous function async (onSubmitted: (value) async { ...), then wait for getSuggestion to finish by await getSuggestion() (do not await inside setState). At this point, _placeList is updated, and you can invoke setState now, things should rebuild properly if there are no other errors.