Callum Slater

Callum Slater

1550909203

React redux: Cannot set on an immutable record

I am trying to update my redux model from my reducer. The model is an extension of an Immutable Record class. I am trying to update the Record with the set method:

import { List, Record } from 'immutable';
import { IFaqItem } from './api.models';

export interface IFaqsState {
loading?: boolean;
items?: List<IFaqItem>;
}
const faqsState = Record({
loading: false,
items: List()
});

class FaqsState extends faqsState implements IFaqsState {
loading: boolean;
items: List<IFaqItem>;

with(props: IFaqsState) {
this.set(‘loading’, props.loading);
return this;
}
}

export default FaqsState;

The reducer contains the following:

case ActionTypes.FAQS_GET_AJAX_RECEIVE:
let response: IFaqsGetResponse = action.payload.response && action.payload.response.response;
return state.with({
loading: false,
items: List(response)
});

However this gives me the following error:

Error: Cannot set on an immutable record.

UPDATE

When I change the reducer from:

let initial = new FaqsState();

const faqsReducer: Reducer<FaqsState> = (state = initial, action: AppActions) => {

to:

const faqsReducer: Reducer<FaqsState> = (state = null, action: AppActions) => {

state = new FaqsState();

it seems to work. Why is it not working when I give the initial state in as an argument?

#reactjs #redux

What is GEEK

Buddha Community

Lyly Sara

1551080454

In your update, whenever your reducer is called, a new state = new FaqsState(); is created.

While in your previous implementation, let initial = new FaqsState(); is one-time created and out-of-scope for the reducer function, and thus the same reference/record is recyclingly used for every subsequent calls of the reducer. When this reducer is first called, the initial is empty and can be called with with to set initial’s value, but after that, initial’s value is already set, and the second call on the reducer will attempt to “overwrite” the initial’s value, result in exception.

However, I would suggest you signature to this for brevity and correctness

const faqsReducer: Reducer<FaqsState> = (state =(new FaqsState()), action: AppActions) => {

because your updated reducer cannot get previous state value.

Elthel Mario

1551148754

Well, it is immutable. When you called the with function you mutated the object, thus violating it’s only constraint.

To avoid that, you should create a new instance with the new values and return it to the store.

Watts Kendall

1551148862

Try to use following approach to update your reducer Define a state

let initialState = {
   // Create an immutable object 
   list: { loading: true, list: []}
};

Then in switch case,

case ActionTypes.FAQS_GET_AJAX_RECEIVE:
    let response: IFaqsGetResponse = action.payload.response && 
    action.payload.response.response;
    return {...initialState.list, loading: false, items:List(response)}

Autumn  Blick

Autumn Blick

1598839687

How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

Reduce Redux Boilerplate Code with Redux-Actions

Redux has become one of the most popular libraries in front-end development since it was introduced by Dan Abramov and Andrew Clark in 2015. They designed it as the successor for Flux, with the support of some developer tools and a few more concepts embedded in it.

Flux is a fancy name for observer pattern further modified to support React. Both Flux and Redux consist of similar concepts like Store, Actions (events in the application). In other words, Flux is a simple JavaScript object but with some middleware like redux-thunk. It can be a function or a promise for Redux. However, Redux is a single source of truth with concepts like immutability, which improve performance. It is one of the main reasons for Redux to dominate in State Management.

Image for post

Flux vs Redux comparison source: enappd.com

Despite its advantages, some developers have found it rather challenging to deal with Redux due to the amount of boilerplate code introduced with it. And the complexity of the code seems to be another reason for the difficulty.

In this article, we will look at how to reduce the boilerplate code brought about by Actions and Reducers using Redux-Actions

#react-redux-boilerplate #react-redux #react #react-actions #redux

Karine  Crooks

Karine Crooks

1589960215

A Basic Redux Setup in React/React Native

Redux is a powerful state management tool that can be very useful as your React or React Native application grows and requires you to keep track of more state. How you want to set up Redux is up to you, but if you’re a beginner, it may be easiest to learn the flow of Redux with a step-by-step walkthrough. Here I’ve outlined a basic way to set up Redux to go along with this post and it will be the same for React and React Native.

#react #react-native #redux #react-redux

Aubrey  Price

Aubrey Price

1590485641

Accessing Redux from Components In React & React Native

How to set up a basic version of Redux in your React or React Native application. To make things clearer, I based my setup on my event application, where users create events that other users attend. We generated the action creators, reducers, and Redux store, and wrapped the application in a provider. Today I’ll finish the loop and talk about how to access the Redux store in your application using both class and functional components. The provider we added to the root component provides the store to all the components in your application. Therefore, we will just look at how to access the store from an individual component.

#react-redux #redux #hooks #react #react-native

Neal  Bode

Neal Bode

1601294220

React Native Redux | How To Use Redux In React Native

React Native Redux Example | How To Use Redux In React Native is today’s leading topic. Redux is a standalone state management library, which can be used with any library or framework. If your background is React developer, then you have used the Redux library with React.

Overview of React Native Redux Example

  • Step 1: Install React Native on mac.
  • Step 2: Add TextBox and Button.
  • Step 3: Define the state and input handler.
  • Step 4: Create actions, reducers, and components folder.
  • Step 5: Create a Reducer function.
  • Step 6: Create a Redux store.
  • Step 7: Pass the store to the React Native app.
  • Step 8: Connect React Native app to the Redux store.

React Native Redux Example Tutorial

The primary use of Redux is that we can use one application state as a global state and interact with the state from any react component is very easy, whether they are siblings or parent-child. Now, let us start the React Native Redux Example Tutorial by installing React Native on Mac first.

We start our project by installing React Native CLI globally on the Mac. You can skip the following command if you have already installed it.

#react native #react native cli #react native on mac #redux #react developer