flutter - Get values of dynamic list of widgets - flutter

Question

I've managed to make a dynamic questionnaire connecting flutter with Firestore.

My custom Question widgets are just a Text() holding the string of the question, and a Slider() so the user can give an answer from 1 to 5

Now that the questions are displayed, how should I get the values?

Here's my code:

var questions = <Widget>[];

//Async read to the DB
Future query() async {
  var snap = await Firestore.instance
    .collection("Forms")
    .document(formID)
    .get();

  var arr = <Widget>[]; //just a temp holder of the widgets
  for(String q in list){
    arr.add(Question(min: 1.0, max: 5.0, question: q, value: 1.0,));
  }

  setState(() {
    questions = arr;
  });
}

And then in the build I'm rendering:

Scaffold(
  body:Container(
    child:Column(
      children: <Widget>[
        Text("Title"),
        Column(
          children: questions,
        ),
        RaisedButton(
          onPressed: () => sendFeedback(),
          color: Colors.redAccent,
          textColor: Colors.white,
          child: Text("Send")
      ]
    )

What would be the code for the sendFeedback() function? I would like to get the values for all the sliders in my children list and then write those to Firestore in only one call to the DB.

标签： flutterflutter-layout

Answer 1

You need to hold the state of all sliders. I'd recommend you the BLoC pattern for state management.

You can read about it here

Edit: You can have a List<int> to hold the values in your bloc and in every slider you will implement the function onChangeEnd: bloc.addValue and send the slider value to the bloc which will add them to the list. Then on the button you will have something like this onPressed: () => bloc.sendFeedback() that will take the values from the list and write them to Firestore.

Keep in mind that this is a solution on the top of my head right now for you to understand the concept