query

@preact-signals/query

@preact-signals/query acts as a bridge between the core functionality of @tanstack/query-core and the reactivity provided by @preact/signals. Designed as a drop-in replacement for @tanstack/react-query, this library not only mirrors its counterpart's functionalities but also offers enhanced hooks tailored for preact signals.

Installation

You should be sure that one of preact signals runtimes installed:

• @preact/signals for preact, it requires additional step
• @preact/signals-react for react

Fetch @preact-signals/query via your preferred package manager:

# Using npm
npm install @preact-signals/query

# Using yarn
yarn add @preact-signals/query

# Using pnpm
pnpm add @preact-signals/query

@preact/signals additional step:

You should resolve @preact/signals-react as @preact/signals To do it take a look at how to resolve react as preact and do it with signals. Plus you need to dedupe preact

Vite example:

import preact from "@preact/preset-vite";
import { defineConfig } from "vite";

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [preact()],
  resolve: {
    // add this line
    dedupe: ["preact"],
    alias: [
      { find: "react", replacement: "preact/compat" },
      { find: "react-dom/test-utils", replacement: "preact/test-utils" },
      { find: "react-dom", replacement: "preact/compat" },
      { find: "react/jsx-runtime", replacement: "preact/jsx-runtime" },
      // add this line
      { find: "@preact/signals-react", replacement: "@preact/signals" },
    ],
  },
});

Table of Contents

• API Overview
• Query Hooks: useQuery$, useInfiniteQuery$
• Mutation Hooks: useMutation$
• Accessing the Client: useQueryClient$
• Filtering with Hooks: useIsFetching$
• Configuring suspense behavior for useQuery$ and useInfiniteQuery$
• License

API Overview

Doumentation

Experience the reactive elegance of @tanstack/react-query with @preact-signals/query.

Although @preact-signals/query adopts the API of @tanstack/react-query, it comes with additional hooks that are specifically optimized for preact signals. You'll recognize these hooks by the appended $ sign:

• useQuery$, useInfiniteQuery$
• useMutation$
• useQueryClient$
• useIsFetching$

Awaited hooks include:

• useQueries$
• useIsMutating$

Query Hooks: useQuery$, useInfiniteQuery$

useQuery$ stands as the reactive counterpart to useQuery from @tanstack/react-query. Instead of the usual reactive object, this hook yields a flat-store.

Primary Differences:

• Adopts the object syntax exclusively.
• Requires a function for options that returns StaticQueryOptions, as they're executed once initially and then reused when reactivity comes into play.
• Results in a flat-store; avoid destructuring.
• Both suspense and useErrorBoundary are demand-triggered. They're invoked at the exact moment the data field is accessed.
• As onError, onSettled, and onSuccess are phased out in react-query, these aren't implemented in reactive query hooks.

Usage

const isUserRegistered = useSignal(false);

const query = useQuery$(() => ({
  queryKey: ["user"],
  queryFn: () => fetchUser(),
  enabled: isUserRegistered.value,
}));

return (
  <>
    <button onClick={() => (isUserRegistered.value = !isUserRegistered.value)}>
      Toggle Registration
    </button>
    <Show when={() => query.data}>
      {(data) => <div>Name: {data().name}</div>}
    </Show>
  </>
);

Suspense Mode

const query = useQuery$(() => ({
  queryKey: ["key"],
  queryFn: fetchStatistics,
  suspense: true,
}));

return (
  <>
    <Profile />
    <Jokes />

    {/* Here, only this segment will enter suspense mode */}
    <Suspense fallback={<Loader />}>
      <Show when={() => query.data}>
        {(data) => (
          <ul>
            {data().map((item) => (
              <li key={item.label}>{item.data}</li>
            ))}
          </ul>
        )}
      </Show>
    </Suspense>
  </>
);

Mutation Hooks: useMutation$

Functionally similar to the query$ hooks, with a couple of nuances:

• Currently, useErrorBoundary isn't available. It's under evaluation for its utility.

Sample Usage

const mutation = useMutation$(() => ({
  mutationFn: doSomething,
  onError: (error) => {
    console.error("doSomething failed", error);
  },
  onSuccess: (data) => {
    console.log("wow we've done something", data);
  },
}));

return <button onClick={mutation.mutate}>Execute Mutation</button>;

Accessing the Client: useQueryClient$

This hook returns the client, encapsulated in signals.

Filtering with Hooks: useIsFetching$

Accepts a reactive callback returning filter options and provides an accessor for the result.

// returns ReadonlySignal<number>
const overallFetching = useIsFetching$(() => null);
const specificFetchCount = useIsFetching$(() => ({
  queryFn: ["123"],
}));

return (
  <>
    <div>Total fetching queries (unoptimized): {overallFetching.value}</div>
    <div>
      Total fetching queries (optimized, no rerenders): {overallFetching}
    </div>
    <div>
      Fetch count by key (optimized, no rerenders): {specificFetchCount}
    </div>
  </>
);

Configuring suspense behavior for useQuery$ and useInfiniteQuery$

If you turn suspense on, the query will fetch after component render (if data is not accessed) or on the first access of data. But you can alter this behavior with suspenseBehavior option (load-on-access is default).

• suspend-eagerly - executes and suspends the query on mount. Data field will always be loaded. Helpful to be access data without worry about .data field will throw a Promise.
• suspend-on-access - pre executes a query, but suspends only on first access of .data field. Helpful to suspend child components if passing accessor as prop.
• load-on-access - executes query on first access of .data field or if unused on useEffect. Legacy behavior, will be changed to suspend-on-access in next major release.

const query = useQuery$(() => ({
  queryKey: ["key"],
  queryFn: fetchStatistics,
  suspense: true,
  suspenseBehavior: "suspend-eagerly",
}));

License

@preact-signals/query is distributed under the MIT License.