somehooks v0.0.4

SomeHooks

A collection of framework agnostic hooks.

Abstract

SomeHooks manages state and side-effects in functional pipelines and works well with asyncronous and callback-driven environments.

Unlike other libraries, SomeHooks do not depend on order, location, or scope.

They can be used anywhere.

Types of Hooks

There are three categories of hooks:

• passive
• reactive
• custom

All hooks are based on the createMemo pattern.

Passive hooks

Most Hooks are passive hooks and cache the result of an expensive operation.

SomeHooks includes the following passive hooks:

• createCallback
• createEffect
• createMemo
• createSelector

Reactive Hooks

A reactive hook requests updates from a given call stack.

Keep in mind, reactive hooks can cause infinite loops.

SomeHooks includes the following reactive hooks:

• createState
• createReducer

Custom Hooks

Passive and reactive hooks can be combined to create custom hooks.

While other environments require transpilation to use hooks alongside components, SomeHooks is scoped to the browser. It requires a more declarative and factory-driven approach.

Keep in mind: custom hooks are potentially comprised of reactive hooks, so custom hooks can cause infinite loops.

A custom hooks should factory return a custom hook function. In the example below, the createClock factory returns a useClock hook.

Typescript:

import type { RequestUpdate } from "somehooks";

const createClock = (requestUpdate: RequestUpdate) => {
  const clockState = createState<string>(requestUpdate);
  const clockEffect = createEffect();

  return () => {
    const [state, setState] = clockState(new Date().toLocaleTimeString());

    clockEffect(() => {
      const stub = setInterval(() => {
        setState(new Date().toLocaleTimeString());
      }, 1000);

      return () => {
        clearInterval(stub);
      };
    }, []);

    return state;
  };
};

Javascript:

const createClock = (requestUpdate) => {
  const clockState = createState(requestUpdate);
  const clockEffect = createEffect();

  return () => {
    const [state, setState] = clockState(new Date().toLocaleTimeString());

    clockEffect(() => {
      const stub = setInterval(() => {
        setState(new Date().toLocaleTimeString());
      }, 1000);

      return () => {
        clearInterval(stub);
      };
    }, []);

    return state;
  };
};

Webcomponents

Custom hooks can isolate complicated logic in webcomponents to a single function call.

Below is a slightly modified version of the createClock factory example found above. It accounts for the isConnected event found in Webcomponents.

Typescript:

import { LitElement, html } from "lit";
import { createState, createEffect } from "somehooks";

import type { RequestUpdate } from "somehooks";

const createClock = (requestUpdate: RequestUpdate) => {
  const clockState = createState<string>(requestUpdate);
  const clockEffect = createEffect();

  return (isConnected: boolean) => {
    const [state, setState] = clockState(new Date().toLocaleTimeString());

    clockEffect(() => {
      if (!isConnected) {
        return;
      }

      const stub = setInterval(() => {
        setState(new Date().toLocaleTimeString());
      }, 1000);

      return () => {
        clearInterval(stub);
      };
    }, [isConnected]);

    return state;
  };
};

Javascript:

import { LitElement, html } from "lit";
import { createState, createEffect } from "somehooks";

const createClock = (requestUpdate) => {
  const clockState = createState(requestUpdate);
  const clockEffect = createEffect();

  return (isConnected) => {
    const [state, setState] = clockState(new Date().toLocaleTimeString());

    clockEffect(() => {
      if (!isConnected) {
        return;
      }

      const stub = setInterval(() => {
        setState(new Date().toLocaleTimeString());
      }, 1000);

      return () => {
        clearInterval(stub);
      };
    }, [isConnected]);

    return state;
  };
};

The createClock hook above is used in the example Webcomponent below.

class MyClock extends LitElement {
  useClock = createClock(() => this.requestUpdate());

  render() {
    const timestring = this.useClock(this.isConnected);

    return html`<p>${timestring}</p>`;
  }
}

License

SomeHooks is released under the Apache License Version 2.0