@ngrx/signals/src/with-linked-state.d.ts

Reactive Store and Set of Utilities for Angular Signals

import { WritableSignal } from '@angular/core';
import { SignalStoreFeature, SignalStoreFeatureResult, StateSignals } from './signal-store-models';
import { Prettify } from './ts-helpers';
type LinkedStateResult<LinkedStateInput extends Record<string | symbol, WritableSignal<unknown> | (() => unknown)>> = {
    [K in keyof LinkedStateInput]: LinkedStateInput[K] extends WritableSignal<infer V> ? V : LinkedStateInput[K] extends () => infer V ? V : never;
};
/**
 * @description
 *
 * Adds linked state slices to a SignalStore.
 *
 * @usageNotes
 *
 * ```typescript
 * const OptionsStore = signalStore(
 *   withState({ options: [1, 2, 3] }),
 *   withLinkedState(({ options }) => ({
 *     selectedOption: () => options()[0],
 *   }))
 * );
 * ```
 *
 * This returns a state of type `{ options: number[], selectedOption: number | undefined }`.
 * When the `options` signal changes, the `selectedOption` automatically updates.
 *
 * For advanced use cases, `linkedSignal` or any other `WritableSignal` instance can be used within `withLinkedState`:
 *
 * ```typescript
 * type Option = { id: number; label: string };
 *
 * const OptionsStore = signalStore(
 *   withState({ options: [] as Option[] }),
 *   withLinkedState(({ options }) => ({
 *     selectedOption: linkedSignal<Option[], Option>({
 *       source: options,
 *       computation: (newOptions, previous) => {
 *         const option = newOptions.find((o) => o.id === previous?.value.id);
 *         return option ?? newOptions[0];
 *       },
 *     })
 *   }))
 * )
 * ```
 *
 * @param linkedStateFactory A function that returns an object literal with properties containing an actual `linkedSignal` or the computation function.
 */
export declare function withLinkedState<State extends Record<string | symbol, WritableSignal<unknown> | (() => unknown)>, Input extends SignalStoreFeatureResult>(linkedStateFactory: (store: Prettify<StateSignals<Input['state']> & Input['props']>) => State): SignalStoreFeature<Input, {
    state: LinkedStateResult<State>;
    props: {};
    methods: {};
}>;
export {};