Dala.Event.Target (dala v0.3.2)

Resolves a target: spec to a concrete delivery pid.

See guides/event_model.md for the full event model.

Forms

Form	Resolves to	When checked
`:parent`	nearest stateful ancestor	render time
`:screen`	the containing screen	render time
`{:component, id}`	named ancestor component	render time
atom	registered process	event time (best-effort)
pid	that pid	n/a
`{:via, mod, key}`	whatever `mod` resolves it to	event time

Resolution returns either {:ok, pid} or {:error, reason}. Callers decide how to handle errors — typically log + drop (for in-tree, this means the target was unmounted; for external, it was never registered).

Summary

Types

render_scope()

The render-time scope used to resolve in-tree targets.

spec()

The user-facing form passed in target: props.

Functions

classify(arg1)

Classify a target spec as :in_tree or :external.

resolve(pid, arg2)

Resolve a target spec to a pid using the render-time scope.

Types

render_scope()

@type render_scope() :: %{
  screen_pid: pid(),
  component_chain: [{Dala.Event.Address.id(), pid()}]
}

The render-time scope used to resolve in-tree targets.

screen_pid — the screen GenServer's pid
component_chain — list of {id, pid} from outermost to innermost stateful ancestor of the widget being registered

spec()

@type spec() ::
  :parent
  | :screen
  | {:component, Dala.Event.Address.id()}
  | atom()
  | pid()
  | {:via, module(), term()}

The user-facing form passed in target: props.

Functions

classify(arg1)

@spec classify(spec()) :: :in_tree | :external

Classify a target spec as :in_tree or :external.

In-tree targets get framework guarantees (staleness check, lifecycle cleanup); external targets are best-effort delivery.

resolve(pid, arg2)

@spec resolve(spec(), render_scope()) :: {:ok, pid()} | {:error, term()}

Resolve a target spec to a pid using the render-time scope.

In-tree forms (:parent, :screen, {:component, id}) are resolved against scope. External forms (atom/pid/via) are resolved against the process registry at the moment of resolution.

Returns {:ok, pid} or {:error, reason}.

Examples

iex> Dala.Event.Target.resolve(:parent, %{screen_pid: self(), component_chain: []})
{:ok, self()}

iex> Dala.Event.Target.resolve(:screen, %{screen_pid: self(), component_chain: []})
{:ok, self()}

iex> Dala.Event.Target.resolve(self(), %{screen_pid: self(), component_chain: []})
{:ok, self()}