@directive-run/svelte

Svelte stores for Directive. Returns Readable stores that work with Svelte's $ auto-subscription syntax.

Install

npm install @directive-run/core @directive-run/svelte

Quick Start

Define a module in a shared file, then use it in any component:

// system.ts
import { createModule, createSystem, t } from "@directive-run/core";

const counter = createModule("counter", {
  schema: {
    facts: { count: t.number() },
    derivations: { doubled: t.number() },
    events: { increment: {}, decrement: {} },
    requirements: {},
  },
  init: (facts) => {
    facts.count = 0;
  },
  derive: {
    doubled: (facts) => facts.count * 2,
  },
  events: {
    increment: (facts) => { facts.count += 1; },
    decrement: (facts) => { facts.count -= 1; },
  },
});

export const system = createSystem({ module: counter });
system.start();

<!-- Counter.svelte -->
<script>
  import { useFact, useDerived, useEvents } from "@directive-run/svelte";
  import { system } from "./system";

  const count = useFact(system, "count");
  const doubled = useDerived(system, "doubled");
  const events = useEvents(system);
</script>

<p>Count: {$count} (doubled: {$doubled})</p>
<button on:click={() => events.increment()}>+</button>
<button on:click={() => events.decrement()}>&minus;</button>

useSelector

Auto-tracking selector over facts and derivations. Returns a Readable store:

<script>
  import { useSelector } from "@directive-run/svelte";
  import { system } from "./system";

  const label = useSelector(system, (state) => {
    return state.count > 10 ? "High" : "Low";
  });
</script>

<span>{$label}</span>

API Reference

Core Hooks

| Hook | Return Type | Description | |------|------------|-------------| | useFact(system, key) | Readable<T> | Subscribe to a single fact value | | useFact(system, [keys]) | Readable<Pick<Facts, K>> | Subscribe to multiple facts | | useDerived(system, key) | Readable<T> | Subscribe to a single derivation | | useDerived(system, [keys]) | Readable<Pick<Derivations, K>> | Subscribe to multiple derivations | | useSelector(system, fn) | Readable<R> | Auto-tracking selector with optional equality function | | useEvents(system) | Events | Events dispatcher | | useDispatch(system) | (event) => void | Low-level dispatch function |

Advanced Hooks

| Hook | Return Type | Description | |------|------------|-------------| | useWatch(system, key, cb) | void | Side-effect on fact or derivation change | | useInspect(system) | Readable<InspectState> | Consolidated system state (isSettled, unmet, inflight) | | useRequirementStatus(plugin, type) | Readable<RequirementTypeStatus> | Requirement loading/error state | | useExplain(system, reqId) | Readable<string \| null> | Human-readable requirement explanation | | useConstraintStatus(system) | Readable<ConstraintInfo[]> | All constraint states | | useOptimisticUpdate(system) | { mutate, isPending: Readable, error: Readable, rollback } | Optimistic mutation with auto-rollback | | useHistory(system) | Readable<HistoryState \| null> | Undo/redo navigation |

Svelte-Specific

| Export | Description | |--------|-------------| | useDirective(module, config?) | Scoped system with lifecycle (auto-start/destroy) | | createFactStore(system, key) | Readable store factory for a single fact | | createDerivedStore(system, key) | Readable store factory for a single derivation | | createDerivedsStore(system, [keys]) | Readable store factory for multiple derivations | | createInspectStore(system) | Readable store factory for system inspection | | createTypedHooks() | Factory for pre-typed hooks | | shallowEqual | Shallow equality helper for selectors |

Peer Dependencies

• svelte >= 4
• @directive-run/core

Documentation

• Svelte Adapter Guide
• API Reference

License

MIT