yandex/city-services-pub/yx-scope-fundamentals

yx_scope: dependency injection without code generation

Scopes are groups of dependencies that share a lifetime. A container declares the graph, a holder creates and drops it, and nothing is static or generated.

Principles (cheat sheet)

Details are in the references below; read one file, not all three.

1. A `Dep` never leaves its container. It is lazy, unique inside the container, and read through

.get. What leaves the container is a public scope interface, not the deps themselves.

1. A separate scope needs start and end conditions of its own. If the lifetime matches the parent

exactly, the answer is a ScopeModule, not a new scope.

1. A child depends on a parent interface, never on the parent container class. That is what keeps

a scope replaceable and testable.

1. Async dependencies are initialized in order. Declare them with asyncDep or rawAsyncDep and

list them in initializeQueue; a missing entry means the dep is never initialized.

1. Scopes create the UI, not the other way round. A container exists independently of the widget

tree, and widgets subscribe to a scope that already exists.

1. In production use `BaseScopeHolder` with an interface, not ScopeHolder<Container>. The short

form belongs to getting-started examples.

References index - topic to file

Beyond this skill

This skill covers the package itself. How a scope fits into the layers of an application, where an Interactor belongs, and what an embeddable feature module exposes to its host are described by the yx-architecture skill. Install it from https://github.com/yandex/city-services-pub/tree/main/yx_architecture when that context is needed.

The state management and navigation packages of the same stack ship their own skills, yx-state-fundamentals and yx-navigation-fundamentals. Install them with fvm dart run skills@ get --agent <your agent> when the project depends on those packages.