ObjectFlagProperty<T> class

A property where the important diagnostic information is primarily whether the value is present (non-null) or absent (null), rather than the actual value of the property itself.

The ifPresent and ifNull strings describe the property value when it is non-null and null respectively. If one of ifPresent or ifNull is omitted, that is taken to mean that level should be DiagnosticLevel.hidden when value is non-null or null respectively.

This kind of diagnostics property is typically used for opaque values, like closures, where presenting the actual object is of dubious value but where reporting the presence or absence of the value is much more useful.

See also:

  • FlagsSummary, which provides similar functionality but accepts multiple flags under the same name, and is preferred if there are multiple such values that can fit into a same category (such as "listeners").
  • FlagProperty, which provides similar functionality describing whether a value is true or false.


ObjectFlagProperty(String name, T? value, {String? ifPresent, String? ifNull, bool showName = false, DiagnosticLevel level = DiagnosticLevel.info})
Create a diagnostics property for values that can be present (non-null) or absent (null), but for which the exact value's Object.toString representation is not very transparent (e.g. a callback).
ObjectFlagProperty.has(String name, T? value, {DiagnosticLevel level = DiagnosticLevel.info})
Shorthand constructor to describe whether the property has a value.


allowNameWrap bool
Whether to wrap the name onto multiple lines or not.
allowTruncate bool
Whether to allow truncation when displaying the node and its children.
no setterinherited
allowWrap bool
Whether to wrap text on onto multiple lines or not.
defaultValue Object?
The default value of this property, when it has not been set to a specific value.
emptyBodyDescription String?
Description to show if the node has no displayed properties or children.
no setterinherited
exception Object?
Exception thrown if accessing the property value threw an exception.
no setterinherited
expandableValue bool
Whether to expose properties and children of the value as properties and children.
hashCode int
The hash code for this object.
no setterinherited
ifEmpty String?
Description if the property description would otherwise be empty.
ifNull String?
Description if the property value is null.
ifPresent String?
Description to use if the property value is not null.
isInteresting bool
Whether to consider the property's value interesting. When a property is uninteresting, its level is downgraded to DiagnosticLevel.fine regardless of the value provided as the constructor's level argument.
no setterinherited
level DiagnosticLevel
Priority level of the diagnostic used to control which diagnostics should be shown and filtered.
no setteroverride
linePrefix String?
Prefix to include at the start of each line.
missingIfNull bool
Whether a value of null causes the property to have level DiagnosticLevel.warning warning that the property is missing a value.
name String?
Label describing the DiagnosticsNode, typically shown before a separator (see showSeparator).
propertyType Type
The type of the property value.
no setterinherited
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
showName bool
Whether the name of the property should be shown when showing the default view of the tree.
no setteroverride
showSeparator bool
Whether to show a separator between name and description.
style DiagnosticsTreeStyle?
Hint for how the node should be displayed.
textTreeConfiguration TextTreeConfiguration?
Returns a configuration specifying how this object should be rendered as text art.
no setterinherited
tooltip String?
Optional tooltip typically describing the property.
value → T?
Returns the value of the property either from cache or by invoking a ComputePropertyValueCallback.
no setterinherited


getChildren() List<DiagnosticsNode>
Children of this DiagnosticsNode.
getProperties() List<DiagnosticsNode>
Properties of this DiagnosticsNode.
isFiltered(DiagnosticLevel minLevel) bool
Whether the diagnostic should be filtered due to its level being lower than minLevel.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
toDescription({TextTreeConfiguration? parentConfiguration}) String
Returns a description with a short summary of the node itself not including children or properties.
toJsonMap(DiagnosticsSerializationDelegate delegate) Map<String, Object?>
Serialize the node to a JSON map according to the configuration provided in the DiagnosticsSerializationDelegate.
toString({TextTreeConfiguration? parentConfiguration, DiagnosticLevel minLevel = DiagnosticLevel.info}) String
Returns a string representation of this diagnostic that is compatible with the style of the parent if the node is not the root.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, TextTreeConfiguration? parentConfiguration, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toTimelineArguments() Map<String, String>?
Converts the properties (getProperties) of this node to a form useful for Timeline event arguments (as in Timeline.startSync).
valueToString({TextTreeConfiguration? parentConfiguration}) String
Returns a string representation of the property value.


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