by method

InheritableAspect<T> by(
  1. InheritableAspectSatisfied<T> fn
)

Add a pre-condition to choosing the correct Inheritable of T when are multiple Inheritable of T in the enclosing context.

For example, If there exists an overriding-hierarchy for String such that

Inheritable<String>(
  key: Key('my-key'),
  value: 'A',
  child: Inheritable<String>(
    value: 'B',
    child: MyWidget(),
  )
)

Ordinarily, value 'B' overrides value 'A', but it can be accessed and depended upon using following construct.

final result = aspect.by((w) => w.key == 'my-key');

Here by runs on the Inheritable itself whereas other similar constructs run on Inheritable.value.

Implementation

InheritableAspect<T> by(InheritableAspectSatisfied<T> fn) {
  return _ByInheritableAspect<T, T>(this, fn);
}