npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

use-immer-state-provider

v1.0.3

Published

React hook and provider for immutable state with actions api

Downloads

38

Readme

use-immer-state-provider

A React state provider and a hook factory to read and manipulate an immutable state using immer and a ✨ magical actions api.

Installation

npm install immer use-immer use-immer-state-provider

API

createImmerStateContext

createImmerStateContext(initialState: T, actions: ActionsT) is similar to createContext. The function returns a Context (same as React's createContext will) and initialValue which will be the initial value of that context and will also expose the types of its elements to the consumer.

  • defaultValue should have the type of the state we would like to have.
  • actions should be an object of functions, where the functions have a signature of (draft: T, ...args)

Extracting the API's type

export type MyStateApi = (typeof result.initialValue)[1];

useImmerStateProvider

useImmerStateProvider(initialState: T, actions: ActionsT, onError?: (e: Error) => any) This hook function is used inside the provider component.

  • Returns [state, api, value]
    • state - Current state (type of initialState)
    • api - An API to update the state (map of functions, static reference; doesn't change), using names from actions and parameters without the first draft parameter
    • value - To be used inside as the context.Provider's value prop.

Example

import { PropsWithChildren, useContext } from "react";
import { createImmerStateContext, useImmerStateProvider } from "use-immer-state-provider";

export type User = { id: string, name: string, email: string };

// Define the state type
type UsersState = {
    users: User[];
};

const initialState: UsersState = {
    users: []
};

const actions = {
  addUser: (draft: UsersState, user: User) => {
      draft.users.push(user);
  },
  deleteUser: (draft: UserState, id: string) => {
      const index = draft.users.findIndex(u => u.id === id);
      if (index > -1) {
          draft.users.splice(i, 1);
      }
  },
  setName: (draft: UserState, id: string, name: string) => {
    const index = draft.users.findIndex(u => u.id === id);
    if (index > -1) {
      draft.users[i].name = name;
    }
  },
  setEmail: (draft: UserState, id: string, email: string) => {
    const index = draft.users.findIndex(u => u.id === id);
    if (index > -1) {
      draft.users[i].email = email;
    }
  },
};

const { context, initialValue } = createImmerStateContext(initialState, actions);

export type UsersApi = (typeof initialValue)[1];

export const useUsers = () => {
  return useContext(context);
};

export const UsersProvider = ({ children }: PropsWithChildren<{}>) => {
  const [, api, value] = useImmerStateProvider(initialState, actions);
  
  // if you want, you can extract state too and do something with it here
  
  return <context.Provider value={value}>{children}</context.Provider>;
};

And inside a component:

import { useUsers } from './usersProvider';

const UserList = () => {
  const [{ users }, api] = useUsers();
  
  return (
      <div>
        <ul>
          {users.map((user, i) => (
            <li key={user.id}>
              {user.name}
              <button onClick={() => api.deleteUser(user.id)}>Delete</button>
            </li>
          ))}
        </ul>
    </div>
  );
}
  • Notice: api.deleteUser(user.id) we use the same function name we created in the actions object but we didn't use the draft argument. This is done by some Typescript magic ✨.
  • Another cool thing you get out of it is that the IDE can detect where a function of the API is being used by searching usages.

License

MIT