CODEWITHSUNDEEP
flutterdartstring-interpolation
IAmJulianAcosta
IAmJulianAcosta

Reputation: 1212

How can I interpolate a String that comes from a Database?

I'm using Firebase with a Flutter application and I need to store in it the value of a String that will be interpolated based on other values from Firebase.

Record in Firebase:

{
  'template': '$amount kg of $fruit',
  'amount': '5',
  'fruit': 'oranges'
}

What I'm doing:

String get amount => _snapshot.data()['amount'];
String get fruit => _snapshot.data()['fruit'];

Widget build(BuildContext context) {

  return Text(_snapshot.data()['template']);
}

What I'm expecting: 5kg of oranges, what Flutter renders: $amount kg of $fruit.

How can I insert the values from amount and fruit in template? The idea is that each record can configure how it will look, so another one can have $fruit: $amount kg or any combination of amount and fruit

Upvotes: 2

Views: 789

Answers (1)

Alexey Inkin
Alexey Inkin

Reputation: 2039

String interpolation is done at compile time and so only works with constant strings. At runtime, a code cannot list variables around, so no interpolation is possible, which is good for both safety and efficiency.

As suggested by ibrahimxcool, use replaceFirst or replaceAll method in String:

_snapshot.data()['template']
  .replaceAll('$amount', amount)
  .replaceAll('$fruit', fruit)
;

Upvotes: 1

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