Is it possible to use a variable within a variable name?

Question

I have a class for Player that has nextDate, loginDate and saveDate. Below code works fine and able to retrieve the fields.

      DocumentSnapshot documentSnapshot =
          await db.collection(Paths.playersPath).doc(uid).get();
      Player player = Player.fromFirestore(documentSnapshot);
      print('print ${player.nextDate}');
      print('print ${player.loginDate}');
      print('print ${player.saveDate}');

My question now is if it is possible to use a variable for the nextDate, loginDate and saveDate so that I can just pass which date should I retrieve. I tried the following but it is not working.

String dateName = 'nextDate';
DocumentSnapshot documentSnapshot =
          await db.collection(Paths.playersPath).doc(uid).get();
      Player player = Player.fromFirestore(documentSnapshot);
      print('print ${player.$dateName}');

Please help. Thanks!

Nimantha · Accepted Answer · 2021-09-17 07:07:07Z

1

As far as the code snippet is concerned, I can see you have already defined a method fromFirebase to serialize it, in that case you must extract the data payload from the DocumentSnapshot provided by the Firebase DB by using the data method provided by the DocumentSnapshot class. The problem in your case is you're trying to serialize the DocumentSnapshot itself which is not a class of type Map<String, dynamic> which is need for json serialization. If you take a look at the docs, the data method provides a Map<String, dynamic>

Another alternative could be

If you are using FlutterFire plugins that are officially developed by the Firebase and Flutter teams, you can use the withConverter method which can serialize the response for you to the Player class in your case. Here you can find more info about the same.

edited Sep 17, 2021 at 7:07

Nimantha

6,5476 gold badges32 silver badges78 bronze badges

answered Aug 3, 2021 at 6:13

gtxtreme

3,9062 gold badges19 silver badges40 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

venir · Accepted Answer · 2021-08-03 08:48:04Z

1

unluckily, in Flutter mirrors are not available. You can look it up in the official documentation about this matter.

Nonetheless, the most straightforward workaround is using a Map, so that the keys in that map are your options, and the values the actual property you want to use.

There's a good example in this previous answer.

answered Aug 3, 2021 at 8:48

venir

2,17211 silver badges25 bronze badges

Collectives™ on Stack Overflow

Is it possible to use a variable within a variable name?

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related