CODEWITHSUNDEEP
flutterdartvisual-studio-code
Augustin R
Augustin R

Reputation: 7809

How does flutter VSCode snippets to extract widget work?

When I use VSCode snippet Extract Widget, I have the following :

class MyExtractedWidget extends StatelessWidget {
    const MyExtractedWidget({
        Key key,
        @required T someVariable,
    }) : _someVariable = someVariable,
        super(key: key);
    final T _someVariable;

    @override 
    Widget build(BuildContext context){ return Container(); }
}

However, I am used to write constructors the following way :

class MyExtractedWidget extends StatelessWidget {
    const MyExtractedWidget({
        Key key,
        @required this.someVariable, // Directly accessing variable using "this"
    }) : super(key: key);
    final T someVariable;

    @override 
    Widget build(BuildContext context){ return Container(); }
}

Do you know why snippets' constructors use a temporary variable instead of directly writing in the variable?

Is it related to encapsulation? If yes, I cannot understand why, as an extracted Widget is written in the same file, and that "underscored" variables are accessible in whole file.

EDIT

I tried with another widget and I have a kind of mix :

class Test extends StatelessWidget {
  const Test({
    Key key,
    @required List<SortedExpense> sortedExpenses,
    @required this.expensesSink,
  }) : _sortedExpenses = sortedExpenses, super(key: key);

  final List<SortedExpense> _sortedExpenses;
  final StreamSink<List<Expense>> expensesSink;
...

Upvotes: 0

Views: 1356

Answers (1)

R&#233;mi Rousselet
R&#233;mi Rousselet

Reputation: 277147

This is based on the privacy of the variables you're extracting.

For example, the following widget:

Text(_count.toString())

will generate:

class MyName extends StatelessWidget {
  const MyName({
    Key key,
    @required int count,
  }) : _count = count, super(key: key);

  final int _count;

  @override
  Widget build(BuildContext context) {
    return Text(_count.toString());
  }
}

while this widget:

Text(count.toString())

will create:

class MyName extends StatelessWidget {
  const MyName({
    Key key,
    @required this.count,
  }) : super(key: key);

  final int count;

  @override
  Widget build(BuildContext context) {
    return Text(count.toString());
  }
}

Upvotes: 1

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