Yes, it is correct. Its just a helper function to have a simpler way to access your state properties Imagine you have a posts key in your App state.posts state.posts // /* { currentPostId: “”, isFetching: false, allPosts: {} } */ And component Posts By default connect()(Posts) will make all state props available for the … Read more
What even is ‘children’? The React docs say that you can use props.children on components that represent ‘generic boxes’ and that don’t know their children ahead of time. For me, that didn’t really clear things up. I’m sure for some, that definition makes perfect sense but it didn’t for me. My simple explanation of what … Read more
Without using any other libraries: import * as axios from “axios”; // Mock out all top level functions, such as get, put, delete and post: jest.mock(“axios”); // … test(“good response”, () => { axios.get.mockImplementation(() => Promise.resolve({ data: {…} })); // … }); test(“bad response”, () => { axios.get.mockImplementation(() => Promise.reject({ … })); // … }); … Read more
Export the store from the module you called createStore with. Then you are assured it will both be created and will not pollute the global window space. MyStore.js const store = createStore(myReducer); export store; or const store = createStore(myReducer); export default store; MyClient.js import {store} from ‘./MyStore’ store.dispatch(…) or if you used default import store … Read more
Assuming that you are using webpack, you need to import the image in order to display it like <img src={require(‘images/06.jpg’)} alt=”product” /> Now that your image data is dynamic, directly specifying the import path like <img src={require(image)} alt=”product” /> doesn’t work. However you can import the image by making use of template literals like <img … Read more
As Context is no longer an experimental feature and you can use Context in your application directly and it is going to be great for passing down data to deeply nested components which what it was designed for. As Mark Erikson has written in his blog: If you’re only using Redux to avoid passing down … Read more
The approach I suggest is a bit verbose but I found it to scale pretty well into complex apps. When you want to show a modal, fire an action describing which modal you’d like to see: Dispatching an Action to Show the Modal this.props.dispatch({ type: ‘SHOW_MODAL’, modalType: ‘DELETE_POST’, modalProps: { postId: 42 } }) (Strings … Read more
I feel like none of the answers have crystallized why mapDispatchToProps is useful. This can really only be answered in the context of the container-component pattern, which I found best understood by first reading:Container Components then Usage with React. In a nutshell, your components are supposed to be concerned only with displaying stuff. The only … Read more
useEffect(callback); // Example useEffect(() => { console.log(“executed after render phase”); return () => { console.log(“cleanup function after render”); }; }); Runs on every component render. Typically used for debugging, analogous to function’s body execution on every render: const Component = () => { callback() return <></>; }; Note: There is still a difference, in execution … Read more
Don’t fall into the trap of thinking a library should prescribe how to do everything. If you want to do something with a timeout in JavaScript, you need to use setTimeout. There is no reason why Redux actions should be any different. Redux does offer some alternative ways of dealing with asynchronous stuff, but you … Read more