@tanstack/db/src/query/live/collection-registry.ts

A reactive client store for building super fast apps on sync

import { LIVE_QUERY_INTERNAL } from './internal.js'
import type { Collection } from '../../collection/index.js'
import type { CollectionConfigBuilder } from './collection-config-builder.js'

const collectionBuilderRegistry = new WeakMap<
  Collection<any, any, any>,
  CollectionConfigBuilder<any, any>
>()

/**
 * Retrieves the builder attached to a config object via its internal utils.
 *
 * @param config - The collection config object
 * @returns The attached builder, or `undefined` if none exists
 */
export function getBuilderFromConfig(
  config: object,
): CollectionConfigBuilder<any, any> | undefined {
  return (config as any).utils?.[LIVE_QUERY_INTERNAL]?.getBuilder?.()
}

/**
 * Registers a builder for a collection in the global registry.
 * Used to detect when a live query depends on another live query,
 * enabling the scheduler to ensure parent queries run first.
 *
 * @param collection - The collection to register the builder for
 * @param builder - The builder that produces this collection
 */
export function registerCollectionBuilder(
  collection: Collection<any, any, any>,
  builder: CollectionConfigBuilder<any, any>,
): void {
  collectionBuilderRegistry.set(collection, builder)
}

/**
 * Retrieves the builder registered for a collection.
 * Used to discover dependencies when a live query subscribes to another live query.
 *
 * @param collection - The collection to look up
 * @returns The registered builder, or `undefined` if none exists
 */
export function getCollectionBuilder(
  collection: Collection<any, any, any>,
): CollectionConfigBuilder<any, any> | undefined {
  return collectionBuilderRegistry.get(collection)
}