CanBuilder class

Builds either way, told whether the action is permitted.

The usually-better alternative to hiding a control. The builder is handed the reason as well as the answer, which is the difference between a greyed-out button and one that says why:

CanBuilder(
  'delete',
  article,
  builder: (context, can) => Tooltip(
    message: can.reason ?? '',
    child: FilledButton(
      onPressed: can.allowed ? () => delete(article) : null,
      child: const Text('Delete'),
    ),
  ),
)
Inheritance

Constructors

CanBuilder(String action, Object? subject, {required Widget builder(BuildContext context, CanResult can), String? field, Key? key})
Builds with the answer to "may action be done to subject".
const

Properties

action → String
What is being attempted.
final
builder → Widget Function(BuildContext context, CanResult can)
Called with the answer, again whenever the rules change.
final
field → String?
One field of it, when the question is that narrow.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
subject → Object?
What it is being attempted on.
final

Methods

build(BuildContext context) → Widget
Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement
Creates a StatelessElement to manage this widget's location in the tree.
inherited
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited