Javascript

Best Practices for Redux

Published Jan 24, 2022

Updated Feb 13, 2023

4 min read

This article was written over 18 months ago and may contain information that is out of date. Some content may be relevant but please refer to the relevant official documentation or available resources for the latest information.

Intro

One year ago, I started to learn Redux for the first time. I was a code newbie, and I had a lot of difficulties understanding Redux! I was annoyed that I couldn't pass props from child components to the parent components in React, and I really needed Redux for that!

I searched for alternatives to use instead of Redux, like React Context APIs, and I was happy with it because it’s already part of React. I didn't want to install any additional packages, and I found it easier to understand than Redux!

In my first big project with React, I used React Context APIs and the project was so big and complex! After a while, the project became increasingly complex until I lost control, and couldn’t even make small changes. Plus, the states in React Context APIs were really a mess!

What is Redux

Redux is a predictable state container for JavaScript apps. It helps you write applications that behave consistently, run in different environments (client, server, and native), and are easy to test. On top of that, it provides a great developer experience, such as live code editing combined with a time-traveling debugger.

Why do we need a Global store?

In all major frontend frameworks like Angular, React, Vue, & Svelte, you can only pass data between your components from the parent components to the child components, and it is super hard to pass the data upward to the parent components! So Redux helps us to share the data easily with our different components!

Redux’s problem

But the real problem with Redux is organizing your files! Most of the tutorials just show you how you can configure a store, create a reducer, use dispatch, …etc, but after you use Redux for a while, you will have a mess of unorganized files, and you will need to learn how to organize the Redux files in your project! In this article, we will learn about the most used Redux patterns in real-world applications!

Also in this tutorial, we will apply all of these patterns to this simple app! It’s a counter app created with create-react-app

Redux Tool Kit (Recommended)

This is the recommended pattern by the Redux core team, RTK is so much simpler and easier than using Redux! It uses slices, a new way to create and write the reducers, initial state and actions.

Each slice file follows this pattern:

import { createSlice } from '@reduxjs/toolkit'

export const counterSlice = createSlice({
  name: 'counter',
  initialState: {
    value: 0
  },
  reducers: {
    increment: state => {
      // Redux Toolkit allows us to write "mutating" logic in reducers. It
      // doesn't actually mutate the state because it uses the immer library,
      // which detects changes to a "draft state" and produces a brand new
      // immutable state based off those changes
      state.value += 1
    },
    decrement: state => {
      state.value -= 1
    },
    incrementByAmount: (state, action) => {
      state.value += action.payload
    }
  }
})

export const { increment, decrement, incrementByAmount } = counterSlice.actions

export default counterSlice.reducer

And finally, we connect the slices with each other in the store.js

import { configureStore } from '@reduxjs/toolkit'
import usersReducer from '../path/to/usersSlice'
import postsReducer from '../path/to/postsSlice'
import commentsReducer from '../path/to/commentsSlice'

export default configureStore({
  reducer: {
    users: usersReducer,
    posts: postsReducer,
    comments: commentsReducer
  }
})

Here is live example, run npm run dev

https://stackblitz.com/edit/vitejs-vite-yaxe7w?ctl=1&embed=1&file=src/App.jsx&hideNavigation=1

Then you’ll use this store for the Redux provider in your app, simple isn’t it?

For more info about this pattern take a look at Redux Essentials, Part 2: Redux App Structure

Pros:

As you see, everything is super organized and easy to edit and read!

Redux ducks

Redux Ducks is a different design pattern created by Erik Rasmussen, and in this pattern, we are merging all of our single reducer files into the reducer file itself, let’s see:

redux/
	ducks/
		counter.js
		// Put all of our reducers here
	store.js

And every reducer (duck file) will be:

const INCREMENT = "counter/INCREMENT";
const DECREMENT = "counter/DECREMENT";

const initialState = {
  count: 0,
};

export default function counter(state = initialState, action) {
  switch (action.type) {
    case INCREMENT:
      return { ...state, count: state.count + 1 };
    case DECREMENT:
      return { ...state, count: state.count - 1 };
    default:
      return state;
  }
}

export const increment = () => ({
  type: INCREMENT,
});

export const decrement = () => ({
  type: DECREMENT,
});

As you can see, we start with declaring our action types, and have no need to export them:

const INCREMENT = "counter/INCREMENT";
const DECREMENT = "counter/DECREMENT";

Then the reducer (MUST BE DEFAULT EXPORTED).

const initialState = {
  count: 0,
};

export default function counter(state = initialState, action) {
  switch (action.type) {
    case INCREMENT:
      return { ...state, count: state.count + 1 };
    case DECREMENT:
      return { ...state, count: state.count - 1 };
    default:
      return state;
  }
}

Finally, create the action types

export const increment = () => ({
  type: INCREMENT,
});

export const decrement = () => ({
  type: DECREMENT,
});

And that’s it! We have a standalone reducer that is so much easier to work with!

Other strategies

There are some software engineers who like to put the reducer next to the files or components that they will use in them:

app/
  modules/
    user/
      __tests__/
        user.reducer.spec.js
      components/
      user.reducer.js	<- the user reducer
    course/
      __tests__/
        course.reducer.spec.js
      components/
      course.reducer.js	<- the course reducer
    lesson/
      __tests__/
      lesson.reducer.spec.js
      components/
      lesson.reducer.js	<- the lesson reducer
  store.js
  index.js

The old pattern

This pattern is used by old apps, it’s not recommended to use it but you may find it when you work on old projects

redux/
	types/
		counter.js
	actions/
		counter.js
	reducers/
		counter.js
	store.js

It is a folder called reducer that contains three other folders. and the store.js file in the root! Let's break them down.

redux/types/counter.js is where we will save the action type as shown below:

export const INCREMENT = "INCREMENT";

export const DECREMENT = "DECREMENT";

We added two action types for the two operations that we want to create, increment, and decrement.

redux/actions/counter.js here we will add all of our action functions for the counter:

import { INCREMENT, DECREMENT } from "../types/counter";

export const increment = () => ({
  type: INCREMENT,
});

export const decrement = () => ({
  type: DECREMENT,
});

First, we imported the types from the types file. Then, we created the two functions of our counter and exported them:

redux/reducers/counter.js is the reducer for our counter.

import { INCREMENT, DECREMENT } from "../types/counter";

const initialState = {
  count: 0,
};

export default function counter(state = initialState, action) {
  switch (action.type) {
    case INCREMENT:
      return { ...state, count: state.count + 1 };
    case DECREMENT:
      return { ...state, count: state.count - 1 };
    default:
      return state;
  }
}

As you see, we imported the counter types again, and created our reducer.

Finally, redux/store.js is where we will combine all of our reducers, and then configure our store:

import { createStore, combineReducers } from "redux";
import counterReducer from "./reducers/counter";

const reducer = combineReducers({
  counter: counterReducer,
});
const store = createStore(reducer);

export default store;

We imported the reducers first! Then we combined reducers, and finally create the store!

Pros:

As you see, everything is super organized, and easy to edit and read!

Cons:

Every reducer needs three files to be created, and this will end up with a massive number of files.

Finally

As you see, there are a lot of cool ideas to keep your Redux file organized. Try them, and choose the pattern that fits your project! And always work to keep your Redux files organized because this would be a game-changer for your project. 😉

This Dot is a consultancy dedicated to guiding companies through their modernization and digital transformation journeys. Specializing in replatforming, modernizing, and launching new initiatives, we stand out by taking true ownership of your engineering projects.

We love helping teams with projects that have missed their deadlines or helping keep your strategic digital initiatives on course. Check out our case studies and our clients that trust us with their engineering.

About the author(s)

Mark Shenouda
@MarkSShenouda @markshenouda

Exploring Angular Forms: A New Alternative with Signals

Exploring Angular Forms: A New Alternative with Signals In the world of Angular, forms are essential for user interaction, whether you're crafting a simple login page or a more complex user profile interface. Angular traditionally offers two primary approaches: template-driven forms and reactive forms. In my previous series on Angular Reactive Forms, I explored how to harness reactive forms' power to manage complex logic, create dynamic forms, and build custom form controls. A new tool for managing reactivity - signals - has been introduced in version 16 of Angular and has been the focus of Angular maintainers ever since, becoming stable with version 17. Signals allow you to handle state changes declaratively, offering an exciting alternative that combines the simplicity of template-driven forms with the robust reactivity of reactive forms. This article will examine how signals can add reactivity to both simple and complex forms in Angular. Recap: Angular Forms Approaches Before diving into the topic of enhancing template-driven forms with signals, let’s quickly recap Angular's traditional forms approaches: 1. Template-Driven Forms: Defined directly in the HTML template using directives like ngModel, these forms are easy to set up and are ideal for simple forms. However, they may not provide the fine-grained control required for more complex scenarios. Here's a minimal example of a template-driven form: ` ` 2. Reactive Forms: Managed programmatically in the component class using Angular's FormGroup, FormControl, and FormArray classes; reactive forms offer granular control over form state and validation. This approach is well-suited for complex forms, as my previous articles on Angular Reactive Forms discussed. And here's a minimal example of a reactive form: ` ` Introducing Signals as a New Way to Handle Form Reactivity With the release of Angular 16, signals have emerged as a new way to manage reactivity. Signals provide a declarative approach to state management, making your code more predictable and easier to understand. When applied to forms, signals can enhance the simplicity of template-driven forms while offering the reactivity and control typically associated with reactive forms. Let’s explore how signals can be used in both simple and complex form scenarios. Example 1: A Simple Template-Driven Form with Signals Consider a basic login form. Typically, this would be implemented using template-driven forms like this: ` ` This approach works well for simple forms, but by introducing signals, we can keep the simplicity while adding reactive capabilities: ` ` In this example, the form fields are defined as signals, allowing for reactive updates whenever the form state changes. The formValue signal provides a computed value that reflects the current state of the form. This approach offers a more declarative way to manage form state and reactivity, combining the simplicity of template-driven forms with the power of signals. You may be tempted to define the form directly as an object inside a signal. While such an approach may seem more concise, typing into the individual fields does not dispatch reactivity updates, which is usually a deal breaker. Here’s an example StackBlitz with a component suffering from such an issue: Therefore, if you'd like to react to changes in the form fields, it's better to define each field as a separate signal. By defining each form field as a separate signal, you ensure that changes to individual fields trigger reactivity updates correctly. Example 2: A Complex Form with Signals You may see little benefit in using signals for simple forms like the login form above, but they truly shine when handling more complex forms. Let's explore a more intricate scenario - a user profile form that includes fields like firstName, lastName, email, phoneNumbers, and address. The phoneNumbers field is dynamic, allowing users to add or remove phone numbers as needed. Here's how this form might be defined using signals: ` > Notice that the phoneNumbers field is defined as a signal of an array of signals. This structure allows us to track changes to individual phone numbers and update the form state reactively. The addPhoneNumber and removePhoneNumber methods update the phoneNumbers signal array, triggering reactivity updates in the form. ` > In the template, we use the phoneNumbers signal array to dynamically render the phone number input fields. The addPhoneNumber and removePhoneNumber methods allow users to reactively add or remove phone numbers, updating the form state. Notice the usage of the track function, which is necessary to ensure that the ngFor directive tracks changes to the phoneNumbers array correctly. Here's a StackBlitz demo of the complex form example for you to play around with: Validating Forms with Signals Validation is critical to any form, ensuring that user input meets the required criteria before submission. With signals, validation can be handled in a reactive and declarative manner. In the complex form example above, we've implemented a computed signal called formValid, which checks whether all fields meet specific validation criteria. The validation logic can easily be customized to accommodate different rules, such as checking for valid email formats or ensuring that all required fields are filled out. Using signals for validation allows you to create more maintainable and testable code, as the validation rules are clearly defined and react automatically to changes in form fields. It can even be abstracted into a separate utility to make it reusable across different forms. In the complex form example, the formValid signal ensures that all required fields are filled and validates the email and phone numbers format. This approach to validation is a bit simple and needs to be better connected to the actual form fields. While it will work for many use cases, in some cases, you might want to wait until explicit "signal forms" support is added to Angular. Tim Deschryver started implementing some abstractions around signal forms, including validation and wrote an article about it. Let's see if something like this will be added to Angular in the future. Why Use Signals in Angular Forms? The adoption of signals in Angular provides a powerful new way to manage form state and reactivity. Signals offer a flexible, declarative approach that can simplify complex form handling by combining the strengths of template-driven forms and reactive forms. Here are some key benefits of using signals in Angular forms: 1. Declarative State Management: Signals allow you to define form fields and computed values declaratively, making your code more predictable and easier to understand. 2. Reactivity: Signals provide reactive updates to form fields, ensuring that changes to the form state trigger reactivity updates automatically. 3. Granular Control: Signals allow you to define form fields at a granular level, enabling fine-grained control over form state and validation. 4. Dynamic Forms: Signals can be used to create dynamic forms with fields that can be added or removed dynamically, providing a flexible way to handle complex form scenarios. 5. Simplicity: Signals can offer a simpler, more concise way to manage form states than traditional reactive forms, making building and maintaining complex forms easier. Conclusion In my previous articles, we explored the powerful features of Angular reactive forms, from dynamic form construction to custom form controls. With the introduction of signals, Angular developers have a new tool that merges the simplicity of template-driven forms with the reactivity of reactive forms. While many use cases warrant Reactive Forms, signals provide a fresh, powerful alternative for managing form state in Angular applications requiring a more straightforward, declarative approach. As Angular continues to evolve, experimenting with these new features will help you build more maintainable, performant applications. Happy coding!...

Oct 4, 2024

5 mins

AngularJavaScript

The HTML Dialog Element: Enhancing Accessibility and Ease of Use

The HTML Dialog Element: Enhancing Accessibility and Ease of Use Dialogs are a common component added to applications, whether on the web or in native applications. Traditionally there has not been a standard way of implementing these on the web, resulting in many ad-hoc implementations that don’t act consistently across different web applications. Often, commonly expected features are missing from dialogs due to the complexity of implementing them. However, web browsers now offer a standard dialog element. Why use the dialog element? The native dialog element streamlines the implementation of dialogs, modals, and other kinds of non-modal dialogs. It does this by implementing many of the features needed by dialogs for you that are already baked into the browser. This is helpful as it reduces the burden on the developer when making their applications accessible by ensuring that user expectations concerning interaction are met, and it can also potentially simplify the implementation of dialogs in general. Basic usage Adding a dialog using the new tag can be achieved with just a few lines of code. ` However, adding the dialog alone won’t do anything to the page. It will show up only once you call the .showModal() method against it. ` Then if you want to close it you can call the .close() method on the dialog, or press the escape key to close it, just like most other modals work. Also, note how a backdrop appears that darkens the rest of the page and prevents you from interacting with it. Neat! Accessibility and focus management Correctly handling focus is important when making your web applications accessible to all users. Typically you have to move the current focus to the active dialog when showing them, but with the dialog element that’s done for you. By default, the focus will be set on the first focusable element in the dialog. You can optionally change which element receives focus first by setting the autofocus attribute on the element you want the focus to start on, as seen in the previous example where that attribute was added to the close element. Using the .showModal() method to open the dialog also implicitly adds the dialog ARIA role to the dialog element. This helps screen readers understand that a modal has appeared and the screen so it can act accordingly. Adding forms to dialogs Forms can also be added to dialogs, and there’s even a special method value for them. If you add a element with the method set to dialog then the form will have some different behaviors that differ from the standard get and post form methods. First off, no external HTTP request will be made with this new method. What will happen instead is that when the form gets submitted, the returnValue property on the form element will be set to the value of the submit button in the form. So given this example form: ` The form element with the example-form id will have its returnValue set to Submit. In addition to that, the dialog will close immediately after the submit event is done being handled, though not before automatic form validation is done. If this fails then the invalid event will be emitted. You may have already noticed one caveat to all of this. You might not want the form to close automatically when the submit handler is done running. If you perform an asynchronous request with an API or server you may want to wait for a response and show any errors that occur before dismissing the dialog. In this case, you can call event.preventDefault() in the submit event listener like so: ` Once your desired response comes back from the server, you can close it manually by using the .close() method on the dialog. Enhancing the backdrop The backdrop behind the dialog is a mostly translucent gray background by default. However, that backdrop is fully customizable using the ::backdrop pseudo-element. With it, you can set a background-color to any value you want, including gradients, images, etc. You may also want to make clicking the backdrop dismiss the modal, as this is a commonly implemented feature of them. By default, the <dialog> element doesn’t do this for us. There are a couple of changes that we can make to the dialog to get this working. First, an event listener is needed so that we know when the user clicks away from the dialog. ` Alone this event listener looks strange. It appears to dismiss the dialog whenever the dialog is clicked, not the backdrop. That’s the opposite of what we want to do. Unfortunately, you cannot listen for a click event on the backdrop as it is considered to be part of the dialog itself. Adding this event listener by itself will effectively make clicking anywhere on the page dismiss the dialog. To correct for this we need to wrap the contents of the dialog content with another element that will effectively mask the dialog and receive the click instead. A simple element can do! ` Even this isn’t perfect though as the contents of the div may have elements with margins in them that will push the div down, resulting in clicks close to the edges of the dialog to dismiss it. This can be resolved by adding a couple of styles the the wrapping div that will make the margin stay contained within the wrapper element. The dialog element itself also has some default padding that will exacerbate this issue. ` The wrapping div can be made into an inline-block element to contain the margin, and by moving the padding from the parent dialog to the wrapper, clicks made in the padded portions of the dialog will now interact with the wrapper element instead ensuring it won’t be dismissed. Conclusion Using the dialog element offers significant advantages for creating dialogs and modals by simplifying implementation with reasonable default behavior, enhancing accessibility for users that need assistive technologies such as screen readers by using automatic ARIA role assignment, tailored support for form elements, and flexible styling options....

Oct 25, 2024

4 mins

HTMLJavaScript

Redux Toolkit 2.0 release

Intro Redux Toolkit On December 4, 2023, Mark Erikson announced that Redux Toolkit 2.0 has been released! This change is considered a major version of the library and comes with breaking changes because, as the core team declared, it has been 4+ years since they released Redux tool kit, and they needed to clean up the code and standardize the way Redux apps are written. One of these changes is you no longer need to import the core redux library, RTK is a wrapper of it. In this article, we are going to focus on the main breaking changes and new features in RTK 2.0 Some general notes on the change * Standalone getDefaultMiddleware and getType removed * The package definitions now include an exports field to specify which artifacts to load, with a modern ESM build * UMD has been dropped * Typescript rewrite createSlice and createReducer One of the major changes is object syntax for createSlice.extraReducers and createReducer removed. In RTK 2.0, Redux team has opted to remove the 'object' form for createReducer and createSlice.extraReducers, as the 'builder callback' form offers greater flexibility and is more TypeScript-friendly, making it the preferred choice for both APIs So an example like this: ` Should be like this: ` Middlewares Now the configureStore.middleware must be a callback. That’s because before to add a middleware to the Redux store, you had to add it to the array of configureStore.middleware, but this is turning off the default middleware. Now it’s a callback function that should return an array with middlewares, the default middleware is being passed in the parameters of the callback function so the developer can include it or not in the middleware array like this: ` Enhancers Store enhancers are a formal mechanism for adding capabilities to Redux itself like adding some additional capabilities to the store. It could change how reducers process data, or how dispatch works. Most people will never need to write one. But similar to the middlewares, enhancers also must be a callback function that receives getDefaultEnhancers and should return enhancers back. ` autoBatchEnhancer In version 1.9.0, the Redux team introduced a new autoBatchEnhancer that, when multiple "low-priority" actions are dispatched consecutively. This enhancement aims to optimize performance by reducing the impact of UI updates, typically the most resource-intensive part of the update process. While RTK Query automatically marks most of its internal actions as "low-pri" users need to add the autoBatchEnhancer to the store for this feature to take effect. To simplify this process, configureStore has been updated to include the autoBatchEnhancer in the store setup by default, allowing users to benefit from improved performance without manual store configuration adjustments. AnyAction and UnknownAction The Redux TS types have historically exported an AnyAction type that lacks precise type safety, allowing for loose typology like console.log(action.whatever). However, to promote safer typing practices, they've introduced UnknownAction, which treats all fields beyond action.type as unknown, nudging users towards creating type guards with assertions for better type safety when accessing action objects. UnknownAction is now the default action object type in Redux, while AnyAction remains available but deprecated. RTK Query behavior They've addressed issues with RTK Query, such as problems with dispatch(endpoint.initiate(arg, {subscription: false})) and incorrect resolution timing for triggered lazy queries, by reworking RTKQ to consistently track cache entries. Additionally, they've introduced internal logic to delay tag invalidation for consecutive mutations, controlled by the new invalidationBehavior flag on createApi, with the default being 'delayed'. In RTK 1.9, the subscription status has been optimized syncing to the Redux state for performance, primarily for display in the Redux DevTools "RTK Query" panel. Conclusion This version is a major version of Redux Toolkit and it has a lot of breaking changes but what is important its source code has been cleaned and rewritten in TS will improve the developer experience for sure and on the final user experience as well, We discussed here only the headlines and the most used features but of course you can find all of the changes on The official Redux Github Releases page...

Mar 8, 2024

3 mins

ReduxJavaScript

AI Leadership: Data-Driven Decision Making & Avoiding "Analysis Paralysis" with Jerry Reghunadh

In this episode of Leadership Exchange, host Rob Ocel chats with Jerry Reghunadh, Senior Director of Enterprise Architecture at Data Nimbus, about leadership, AI adoption, and data-driven decision-making. Jerry shares his career journey, insights on leveraging tools like ChatGPT and Copilot, and strategies for building effective data pipelines. They explore how companies can avoid "analysis paralysis," adopt AI strategically, and evaluate new technologies to solve real-world problems. Tune in for practical advice on aligning innovation with business goals and staying competitive in a rapidly evolving tech landscape. Chapters 00:00 – Introduction 00:31 – Jerry’s Leadership Journey 02:01 – Discussing AI in Leadership 03:59 – Experimenting with AI Tools 06:24 – Overcoming Analysis Paralysis 09:18 – Importance of Early AI Adoption 13:12 – AI’s Impact on Efficiency 14:30 – Sponsor Message 16:26 – Setting Realistic Goals for AI 19:41 – Data Management and AI 23:09 – Is AI Just a Fad? 27:22 – Testing New Technologies 29:56 – Final Thoughts on AI 30:25 – Connect with Jerry 30:44 – Closing Remarks 31:20 – Outro Follow Jerry on Social Media Linkedin: https://www.linkedin.com/in/jerrymannel/ Sponsored by This Dot: thisdot.co...

Nov 18, 2024

1 min

AIEngineering Leadership

Let's innovate together!

We're ready to be your trusted technical partners in your digital innovation journey.

Whether it's modernization or custom software solutions, our team of experts can guide you through best practices and how to build scalable, performant software that lasts.

Best Practices for Redux

Intro

What is Redux

Why do we need a Global store?

Redux’s problem

Redux Tool Kit (Recommended)

Redux ducks

Other strategies

The old pattern

Finally

Mark Shenouda

You might also like

Exploring Angular Forms: A New Alternative with Signals

The HTML Dialog Element: Enhancing Accessibility and Ease of Use

Redux Toolkit 2.0 release

AI Leadership: Data-Driven Decision Making & Avoiding "Analysis Paralysis" with Jerry Reghunadh

Let's innovate together!

You might also like

Exploring Angular Forms: A New Alternative with Signals

The HTML Dialog Element: Enhancing Accessibility and Ease of Use

Redux Toolkit 2.0 release

AI Leadership: Data-Driven Decision Making & Avoiding "Analysis Paralysis" with Jerry Reghunadh