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

@bitovi/use-simple-reducer

v1.0.0

Published

A reducer to handle async actions

Downloads

246

Readme

use-simple-reducer

Build Version Types Size Dependencies Pull Requests welcome

useSimpleReducer is a simple async state mechanism for ReactJS. It's designed to be used for managing service state data and result in easy-to-test reducer methods.

Need help or have questions?

This project is supported by Bitovi, an end-to-end JavaScript consultancy specializing in React. You can get help or ask questions on our:

Or, you can hire us for training, consulting, or development. Set up a free consultation.

Table of Contents

Install

npm i @bitovi/use-simple-reducer

The Hook

Use

In your component, call useSimpleReducer with:

| Field | Type | Purpose | | -------------- | -------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | initialState | any | The initial state you want to manage. | | actions | {[key: string]: (state: any, payload: any) => any} | A collection of reducer methods, each to be called with thestate as the first argument and values passed to the action method as the second argument. If you are unfamiliar with the reducer pattern you can check out the redux reducer. |

function Counter() {
  const [state, actions, queue, error] = useSimpleReducer(
    // initial state
    { count: 0 },
    // collection of reducer methods
    {
      async add(state: CounterState, amountToAdd: number) {
        await updateCountOnServer(state.count + amountToAdd)
        return { ...state, count: state.count + amountToAdd }
      },
      async subtract(state: CounterState, amountToSubtract: number) {
        await updateCountOnServer(state.count - amountToSubtract)
        return { ...state, count: state.count - amountToSubtract }
      },
    },
  )
}

useSimpleReducer returns:

| Field | Type | Purpose | | --------- | ----------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- | | state | {[key: string]: any} | The latest state. This will initially return the initial state value, then it will return the values returned by the reducer methods. | | queue | { isActive: boolean, pendingAction: ActionAndArgs[], runningAction : ActionAndArgs} | The queue's state, whether it is still active and details of the running and pending actions in the queue. | | actions | {[key: string]: (arg: any) => void} | An object of methods that can be used to update the state. | | error | Error | null | An error that is returned if any of the actions fail, null if otherwise. |

When the user interacts with the page, call the actions methods. For example, you might call actions.add and actions.subtract as follows:

return (
  <div>
    <button onClick={() => actions.add(2)}>Two Steps Forward</button>
    <button onClick={() => actions.subtract(1)}>One Step Back</button>
    <div>
      <p>Steps: {state.count}</p>
      <div>{queue.isActive ? <Loader /> : 'Processing completed'}</div>
    </div>
  </div>
)

The argument being passed to actions methods here actions.add(2) should match the type of the payload argument amountToAdd being passed to the reducer method async add (state, amountToAdd)

async add(state: CounterState, amountToAdd: number){
    return { ...state, count: state.count + amountToAdd };
}

The Queue

Any invoked reducer action gets added to a queue. The queue will then start processing those asynchrous actions in the same order they have been added. The isActive flag gets set to false once all actions has been processed.

Interface

| Field | Type | Purpose | | ---------------- | --------------- | --------------------------------------------------------------------------------------------------------------------------------------- | | isActive | boolean | true if an async action is running, false if otherwise. This can be used to add loading, spinners or other UI elements to the page. | | runningAction | ActionAndArgs | Details of the running action which include the action's name, method and arguments. | | pendingActions | ActionAndArgs[] | An Array of details of the pending actions in the queue which include the actions' names, methods and arguments. |

Error Handling

An error object gets returned if any of the reducer methods fails. The cause of the error, details of the failed action and some error handling methods are exposed as part of the object.

Use

    return (
        <div>
            <button onClick={()=> actions.add(2)}>Two Steps Forward</button>
            <button onClick={()=> actions.subtract(1)}>One Step Back</button>
            <div>
                <p>Steps: {state.count}</p>
                <div>{queue.isActive ? <Loader /> : "Processing completed"}</div>
            </div>
            {error && <AlertDialog content={error.reason} onConfirm={() => error.runFailedAction()} />}
        </div>
    );
}

Interface

The error could contain the following fields:

| Field | Type | Purpose | | ------------------- | --------------- | -------------------------------------------------------------------------------------------------------------------- | | reason | any | The cause of the error. This can be of any type depending on the error thrown. | | failedAction | ActionAndArgs | Details of the failed action which include the action's name, method and arguments. | | pendingActions | ActionAndArgs[] | An array of the details of the pending actions in the queue which include the actions' names, methods and arguments. | | runFailedAction | () => void | An error recovery method to re-run the last failed action. | | runPendingActions | () => void | An error recovery method to skip the failed action and only run the pending actions in the queue. | | runAllActions | () => void | An error recovery method to re-run the failed action and all the pending actions in the queue. |

Unless the user calls any of the error recovery methods listed above, a default behaviour of the queue is to clear the failed and pending actions in it once an error occurs.

Demonstration

CodeSandBox:

https://codesandbox.io/s/bitovi-use-simple-reducer--basic-91ywsu?file=/src/components/Counter/Counter.tsx

We want to hear from you.

Come chat with us about open source in our community Slack.

See what we're up to by following us on Twitter.