ModuleStackCodec<R extends KaiselRoute> class abstract

Codec for a module's URL structure, relative to whatever prefix the host mounts the module at.

Module authors implement this to make their module URL-addressable. The host composes it via ConfigCodecWithModules without needing to know the module's internal route types. The module ships as a self-contained unit.

class CheckoutModuleCodec extends ModuleStackCodec<CheckoutRoute> {
  const CheckoutModuleCodec();

  @override
  List<String> encode(List<CheckoutRoute> stack) => switch (stack.last) {
    CheckoutCart() => const [],
    CheckoutShipping() => const ['shipping'],
    CheckoutConfirm() => const ['confirm'],
  };

  @override
  List<CheckoutRoute>? decode(List<String> segments) => switch (segments) {
    [] => const [CheckoutCart()],
    ['shipping'] => const [CheckoutCart(), CheckoutShipping()],
    ['confirm'] => const [
      CheckoutCart(), CheckoutShipping(), CheckoutConfirm(),
    ],
    _ => null,
  };
}

Conventions:

• encode of the module's root state returns const []. The mount prefix alone (e.g. /checkout) is enough.
• decode of const [] should return the module's root stack (typically initialStack), so visiting just the prefix lands the module at its starting position.
• Return null from decode for unknown segment patterns. The parser falls back to its configured fallback stack.

Implemented types

• UntypedModuleStackCodec

Constructors

ModuleStackCodec()

Const constructor so subclasses can be const.

const

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

Methods

decode(List<String> segments) → List<R>?

Decode URL segments (relative to the mount prefix) into a module stack. Return null if the segments don't match any known route in this module.

decodeAny(List<String> segments) → List<KaiselRoute>?

Decode URL segments to a stack of routes, or null if the segments don't match any known route in this module. Implementations upcast their specific route subtype to KaiselRoute for the composer.

override

encode(List<R> stack) → List<String>

Encode the module's stack to URL segments. The result is appended to the host's mount prefix to produce the full URL. Return const [] for the module's root state.

encodeAny(List<KaiselRoute> stack) → List<String>

Encode any stack of routes to URL segments. Implementations downcast to their module's specific route type internally.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited