Idiomatic Dart: explicitly define list with optional component?

Question

In Dart / Flutter a Row widget can be written like this:

Row(
  children: <Widget>[
    Text('a'),
    Text('b'),
  ],
)

How could that be changed if the second text should only be added if a condition is met? It could be:

bool condition = ...;
List<Widget> rowComponent = [Text('a')];
if(condition) {
  rowComponent.add(Text('b'));
}

Row(
  children: rowComponent,
);

Is there a more idiomatic and less verbose way? Something like:

bool condition = ...; 
Row(
  children: <Widget>[
    Text('a'),
    condition ? Text('b') : Container(), 
  ],
)

This does work but only in the context of Flutter (where the Container can be used as a "void object") and creates this unused Container. Is there a better way?

Thanks!

Answer 1

What about this way? Maybe you like this one.

You don't need to use the Container()

bool condition = ...; 

Row(
  children: <Widget>[
    if (condition) Text('c'),
  ],
)

Reference to this: prefer_if_elements_to_conditional_expressions

Answer 2

I do something like this:

bool notNull(Object o) => o != null;

bool condition = ...; 
Row(
  children: <Widget>[
    Text('a'),
    condition ? Text('b') : null, 
  ].where(notNull).toList(),
)

This is also useful if you have a method that will either create and returna Widget, or return null.