shelving/react/createDBContext.js

Toolkit for using data in JavaScript.

import { jsx as _jsx } from "react/jsx-runtime";
import { createContext, use } from "react";
import { DBCache } from "../db/cache/DBCache.js";
import { RequiredError } from "../error/RequiredError.js";
import { useInstance } from "./useInstance.js";
import { useStore } from "./useStore.js";
/**
 * Create a data context
 * - Allows React elements to call `useItem()` and `useQuery()` to access items/queries in a database provider.
 * - If the database has a `CacheDBProvider` in its chain then in-memory data will be used in the returned stores.
 */
export function createDBContext(provider) {
    const CacheContext = createContext(undefined);
    function useItem(collection, //
    id) {
        const cache = use(CacheContext);
        if (!cache)
            throw new RequiredError("useItem() can only be used inside <DBContext>", { caller: useItem });
        return useStore(collection && id ? cache.getItem(collection, id) : undefined);
    }
    function useQuery(collection, //
    query) {
        const cache = use(CacheContext);
        if (!cache)
            throw new RequiredError("useQuery() can only be used inside <DBContext>", { caller: useQuery });
        return useStore(collection && query ? cache.getQuery(collection, query) : undefined);
    }
    function DBContext({ children }) {
        const cache = useInstance(DBCache, provider);
        return _jsx(CacheContext, { value: cache, children: children });
    }
    return { useItem, useQuery, DBContext };
}