Chain class

A chain of stack traces.

A stack chain is a collection of one or more stack traces that collectively represent the path from main through nested function calls to a particular code location, usually where an error was thrown. Multiple stack traces are necessary when using asynchronous functions, since the program's stack is reset before each asynchronous callback is run.

Stack chains can be automatically tracked using Chain.capture. This sets up a new Zone in which the current stack chain is tracked and can be accessed using Chain.current. Any errors that would be top-leveled in the zone can be handled, along with their associated chains, with the onError callback. For example:

Chain.capture(() {
  // ...
}, onError: (error, stackChain) {
  print("Caught error $error\n"
        "$stackChain");
});

Implemented types

• StackTrace

Constructors

Chain(Iterable<Trace> traces)

Returns a new Chain comprised of traces.

Chain.current([int level = 0])

Returns the current stack chain.

factory

Chain.forTrace(StackTrace trace)

Returns the stack chain associated with trace.

factory

Chain.parse(String chain)

Parses a string representation of a stack chain.

factory

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

terse → Chain

Returns a terser version of this chain.

no setter

traces → List<Trace>

The stack traces that make up this chain.

final

Methods

foldFrames(bool predicate(Frame), {bool terse = false}) → Chain

Returns a new Chain based on this chain where multiple stack frames matching predicate are folded together.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

override

toTrace() → Trace

Converts this chain to a Trace.

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

capture<T>(T callback(), {void onError(Object error, Chain)?, bool when = true, bool errorZone = true, Map<Object?, Object?>? zoneValues}) → T

If when is true, runs callback in a Zone in which the current stack chain is tracked and automatically associated with (most) errors.

disable<T>(T callback(), {bool when = true}) → T

If when is true and this is called within a Chain.capture zone, runs callback in a Zone in which chain capturing is disabled.

track(Object? futureOrStream) → dynamic

Returns futureOrStream unmodified.