Dapper is a blazing fast and lightweight framework for managing state in a Javascript app.

Features

• 💨 Fast − Our APIs just run lightning fast, no more slowdowns.
• 🔋 Efficient - To reduce the consumption of energy, we have optimised it.
• ⛑ Type Safe - To prevent type errors and bugs, we have made the framework type-safe.
• 🛳 Portable - This framework works accorss web and Node environments. You can use this library together with React or any other Javascript UI libraries.
• 😵 Tiny (>2kb) - Too much lightweight, no more large bundle sizes
• 🤓 Extensible - Extend the State class to create your own custom state object.

Installation

You can install this package using NPM, Yarn or PNPM using the specific command.

NPM

npm i @thq/dapper

Yarn

yarn add @thq/dapper

PNPM

pnpm add @thq/dapper

Documentation

APIs

State

The State class is the main API that powers all of the other APIs. You can create your own custom state class by extending this one. This API introduces a whole another world of possibilities and provides more flexibility and customasibility.

Classic

const name = new State(10);

name.onChange = newValue => {
	console.log(newValue());
};

Extended State:

import { State, createState } from 'dapper';

class CredentialsStore extends State<string> {
	verifyValue(value: string) {
		return value.length > 5;
	}

	// You can also override other methods like
	get() {}
	set() {}

	onChange = newValue => {};

	// You could also add a custom action
	// to organise your code.
	fetchData() {}
}

// you can call the actions inside your state
const [name, setName, nameInstance] = createStateWith(
	CredentialsStore('some-name')
);

nameInstance.get();

createState()

Creates a new State object and returns an instance of it. This function is just a simplified form of the State class. If you wanna read about the usage, you might need to checkout the State API.

Usage:

const isPrivate = createState(false);

isPrivate.get();

isPrivate.set(true);

With Initial Effect:

const isPrivate = createState(false);

createStateWith()

Alternative to the createState() API but instead also adds support for extensibility of a custom state class. Althought the return value of this function is same as the createState() API, the function doesn't expect a value directly and instead the instance of the extended class. But you can pass the initialEffect as the second argument.

class CustomClass<T> extends State<T> {
	...
}

const state = createStateWith(
	new CustomClass(...)
);

Example

import { createState } from 'dapper';

/**
 * Creates a new state object and returns an array of three elements with
 * the first one as the getter and second one as the setter and the third
 * one is the instane of the state object, this might be needed in
 * scenarios when you need to use `registerEffect()` hook
 * Expects a default value in the first parameter. The secon
 * parameter is an optional initial effect callback. I
 * passes in the initial value passed in to the `createState
 * function. This was created in order to fix the
 * accessing the value before it was initialised error.
 *
 * The getter is a function, so you would you have to call it to get the
 * state.
 *
 * The setter is also a function which you need to provide a new value to
 * be passed in to the function. If the new value passed in is the same as
 * the old one is used and the new unchanged value is ignored.
 * This function is type-safe and if the new value's type is not the same
 * as the new one, it will throw an error.
 *
 * The instance is a object that has the value of the state object created
 * by registerEfffect() hook.
 */
const username = createState('anonymous');

/**
 * Registers an hook to trigger whenever a change is made. If you need to
 * detect changes from the creation of the state, you would need to register
 * it right after creating the state. This means that the changes would only
 * be detected after this hook is registered and not from the beginning.
 * So it would improve perfomance as it would help the developer optimise
 * triggering changes according to their apps.
 *
 * The first parameter is the callback when a new value is triggered. This
 * function also passes in the new value.
 *
 * The second parameter is instance of the state object. You can get the
 * instance from the createState() hook.
 */
username.onChange = newValue => {
	console.log(newValue);
};

// retrieving the value from the state.
username.get();

// setting the state, the callback inside the registerEffect() hook
// is triggered
username.set('hello-world');

License

dapper is licensed under MIT and the copyright is owned by Haneen Mahdin.