LogSpan class abstract

Base class for all log spans - a mutable tree structure.

Spans are composable building blocks for log output. Each span knows its parent and can be manipulated in place (replaced, removed, wrapped).

Class hierarchy

LogSpan (abstract base)
├── LeafSpan (no children)
│   ├── PlainText
│   ├── Whitespace
│   ├── NewLine
│   └── EmptySpan
├── SingleChildSpan (one child)
│   ├── AnsiStyled
│   └── Bordered
├── MultiChildSpan (ordered children)
│   └── SpanSequence
└── SlottedSpan (named children)
    └── Surrounded

Example: Custom span

class EmojiSpan extends LeafSpan {
  final String emoji;

  EmojiSpan(this.emoji);

  @override
  void render(ConsoleMessageBuffer buffer) {
    buffer.write(emoji);
  }
}

Example: Transforming spans

void transform(LogSpan root, LogRecord record) {
  // Replace timestamp with emoji
  root.findFirst<Timestamp>()?.replaceWith(LevelEmoji(record.level));

  // Remove class name
  root.findFirst<ClassName>()?.remove();

  // Wrap message with border
  root.findFirst<Message>()?.wrap((child) => Bordered(child: child));
}

Implementers

Annotations

@experimental

Constructors

LogSpan(): Base class for all log spans - a mutable tree structure.

Properties

allAncestors → Iterable<LogSpan>: Returns all ancestors from parent to root.
no setter
allChildren → Iterable<LogSpan>: All direct children of this span.
no setter
allDescendants → Iterable<LogSpan>: Returns all descendants (including self) in pre-order.
no setter
hashCode → int: The hash code for this object.
no setterinherited
parent → LogSpan?: Parent span in the tree, or null if this is the root.
no setter
root → LogSpan: Returns the root span of the tree.
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

build() → LogSpan: Builds this span into another span, or returns itself if already terminal.
findAll<T extends LogSpan>() → Iterable<T>: Finds all descendants (including self) of type T.
findFirst<T extends LogSpan>() → T?: Finds the first descendant (including self) of type T.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
remove() → bool: Removes this span from its parent.
render(ConsoleMessageBuffer buffer) → void: Renders this span to the buffer.
replaceWith(LogSpan newSpan) → bool: Replaces this span in its parent with newSpan.
toString() → String: A string representation of this object.
inherited
wrap(LogSpan wrapper(LogSpan child)) → void: Wraps this span with a wrapper span.

Operators

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