# adaka

> High-precision state management using MongoDB query language.

Latest version **0.1.0** (published 2024-11-28) · MIT license · 0 weekly downloads

## Install

```sh
npm install adaka
pnpm add adaka
yarn add adaka
bun add adaka
```

## Health

**Score 35/100 (D)** — status: maintenance-mode.

Positive: has types; esm support; no vulnerabilities.

Warnings: low downloads; pre 1.0.

Negative: stale; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.1.0 |
| Published | 2024-11-28 |
| First published | 2023-06-03 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 1 |
| Unpacked size | 43.8 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 4 |
| Author | Francis Asante |
| Maintainers | kofrasa |
| Keywords | state, query, project, immutable, observable |

## Links

- npm: https://www.npmjs.com/package/adaka
- Repository: https://github.com/kofrasa/adaka
- Homepage: https://github.com/kofrasa/adaka#readme
- Issues: https://github.com/kofrasa/adaka/issues
- npm.io page: https://npm.io/package/adaka

## Dependencies (1)

- [mingo](https://npm.io/package/mingo.md) ^6.5.0

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## Recent versions

- 0.1.0 (latest) — 2024-11-28
- 0.0.11 — 2024-03-23
- 0.0.10 — 2024-03-04
- 0.0.9 — 2024-02-29
- 0.0.8 — 2024-02-27
- 0.0.7 — 2023-09-27
- 0.0.6 — 2023-09-26
- 0.0.5 — 2023-06-26
- 0.0.4 — 2023-06-25
- 0.0.3 — 2023-06-09
- 0.0.2 — 2023-06-08
- 0.0.1 — 2023-06-04
- 0.0.0 — 2023-06-03

## README

# adaka

High-precision state management using MongoDB query language.

![license](https://img.shields.io/github/license/kofrasa/adaka)
[![version](https://img.shields.io/npm/v/adaka)](https://www.npmjs.org/package/adaka)
[![build](https://github.com/kofrasa/adaka/actions/workflows/build.yml/badge.svg)](https://github.com/kofrasa/adaka/actions/workflows/build.yml)
![issues](https://img.shields.io/github/issues/kofrasa/adaka)
[![codecov](https://img.shields.io/codecov/c/github/kofrasa/adaka)](https://codecov.io/gh/kofrasa/adaka)
[![npm downloads](https://img.shields.io/npm/dm/adaka)](https://www.npmjs.org/package/adaka)

## Install

`npm i adaka`

## Features

- Manage state as a single document modifiable only through the store API.
- Update state using MongoDB [update query](https://www.mongodb.com/docs/manual/reference/operator/update/) language.
- Use selectors to precisely observe specific data in state and subscribe to be notified only when they change.
- Subscribers are notified with a frozen immutable object.
- Restrict state notifications with conditions expressed as queries.
- Automatically unsubscribes a listener if it throws an exception.
- Performs value equality using deep equal.
- React integration via [react-adaka](https://www.npmjs.com/package/react-adaka).

## Usage

### Import the `createStore` function to get started.

```ts
import { createStore } from "adaka";
```

### Create store and select some data.

```ts
type Person = { name: string; age: number; children?: string[] };

const store = createStore<Person>({
  name: "John",
  age: 30,
  children: ["Luke"]
});

// create a selector
const selector = store.select<{ name: string }>({ name: 1 });

// subcriber runs whenever name changes.
const unsubscribe = selector.subscribe(view => {
  console.log("->", view);
});

// first update
store.update({ $set: { name: "Amoah" } }); //output: '-> {name:"Amoah"}'

// can also use selector.getState() to obtain the value directly.
console.log(selector.getState()); // {name: "Amoah"}

// second update
store.update({ $set: { name: "Donkor" } }); //output: '-> {name:"Donkor"}'

// third update on different part of the state. subscriber is not notified.
store.update({ $push: { children: "Ama" } }); // no output

// remove subscriber by calling return method.
unsubscribe();

// subscriber no longer runs
store.update({ $set: { name: "Odame" } }); // no output
```

### Select data only on condition
A selector may use a condition to restrict when listeners are notified. When a condition is used listeners are notified
only once for when the condition is false with a return value of `undefined`. Further updates that do not meet the condition
do not trigger anymore notifications. On the other hand, any update that meets the condition triggers a notification.

```ts
// store object.
// ------------
// {
//   name: "John",
//   age: 30,
//   children: ["Luke"]
// }

// second child if person under 30.
const selector = store.select<{ secondChild: string }>({
  secondChild: "$children.1"
}, {age: {$lt: 30}});

selector.subscribe(data => {
  console.log("->", data);
});

selector.getState() // undefined

store.update({$set: {age: 25}})
// no second child yet.
selector.getState() // {}

store.update({ $push: { children: "Adrian"} })
selector.getState() // { secondChild: 'Adrian' }. listeners notified.

store.update({ $set: { age: 35 } })
selector.getState() // undefined. listeners notified.

store.update({ $set: { age: 40 } })
selector.getState() // undefined. no notifications because condition is false.
```

### React Integration
The [react-adaka](https://www.npmjs.com/package/react-adaka) and React `>=18.2.0` libraries are required to use this integration.

```jsx
import { createStore, createSelectorHook } from "react-adaka"

// first create your store
const store = createStore({
  status: "error",
  errors: [
    { type:"api", message: "unknown error" }
  ],
});

// create a selector hook some where in global scope. need one per store.
const useSelector = createSelectorHook(store)

// use the hook inside your React component.
function ShowErrorTypes() {
  // select the types of errors only when the status is in "error".
  const { errorTypes } = useSelector({ errorTypes: "$errors.type" }, { status: "error"})

  return errorTypes ? <div>Issues found: {errorTypes.join("\n")} </div> : <div/>
}
```

## MongoDB Query and Update Support

This package uses the [mingo](https://npmjs.com/package/mingo) library for MongoDB query language support and loads only the basic supported `query`, `projection`, `expression`, and all `update` operators by default. Refer to the [readme](https://www.npmjs.com/package/mingo) page for more information.

The `mingo` libray is added as a **peer dependency** to enable users to select only required operators using the `context` option so that tree-shaking can work effectively. Basic `mingo` operators are loaded into the global context by default.

## TODO

- Support schema validation

## License
MIT

---
_Source: https://npm.io/package/adaka · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._