I am new in react and redux. I have a button on a component on click of that I am calling api and set the response as state. But I want that state back to clicked function where on base of that state I want some conditional work.
I dont think how to implement this.
Thanks,
Vijay
You need to use Connect.
Connects a React component to a Redux store.
It does not modify the component class passed to it.
Instead, it returns a new, connected component class, for you to use.
You need to use mapDispatchToProps so that your data is back to you at the component once fetched/retrieved making the component re-rendered, and that's what you need and that's the killing feature of Redux uni-directional flow archticeture.
Related
Im creating a popup that will be shown to the user after login. He should select an option that will be shared in all components as prop. Everytime this popup is open and the value change, all the component should be updated. Do you have any tips on how I should do it. Thanks
The best way would be using redux or context to have global state that can be shared with all of your components. I do not know your app volume and component numbers but if you are looking for a basic way for basic app, you can set this popup states in parent component of your app and pass this state as props to your children components. Another way would be implementing this with backend that you can do post request each time when you change your popup data and do get request in your children components
Let's say I have a music component connected to the "play" prop in the redux store.
When "play" is updated, I would like to update the playback status (play, pause, etc) accordingly. However, this does not influence how the component looks. So I'm wondering where to perform the update actions?
I was using componentWillReceiveProps to control the playback when the prop is updated, it works but apparently that is incorrect use according to the React team, and the method will be deprecated.
You need to dispatch an action with the selected playback status within the onClick function that is passed through a reducer and updates the state of the store. The component, if connected properly to the store using the connect function in the react-redux library, will automatically update the rendering of the component.
I'm new to React and I'm trying to figure out the best way to request information from the server based on the URL. I'm using Redux and React Router v4.
Let's say I have a route /foo/:id, and a component Foo that will render something based on id. However Foo needs some server data related to id to do so. I believe the way to accomplish this would be to use mapDispatchToProps to create a function that takes id as input, does some async work, dispatches an action, and ultimately updates the redux state.
My question is: where is the most appropriate place to invoke the dispatch? In this scenario, there's no form submission or button click to kick things off. Originally I was thinking of including a check for the id data in render() and fetching if it was not populated, but this felt wrong due to the side effects.
You can do it in componentDidMount of the Foo component, similar to this example from the Redux GitHub project.
Your intuition is right that render is not a good place to do so. Most people do it in the componentDidMount lifecycle method of the component.
On a relevant note, you will also want to do fetching also in the componentWillReceiveProps method like what they did here. Reason being if your user navigated from foo/1/ to foo/2/, the component is already on the screen and will not be mounted again, hence componentDidMount will not be called again. The fetching for the second user will be done in the componentWillReceiveProps method.
i think the best way to do the dispatch inside the componentWillReceiveProps() which would help you fetch some data before the component renders
It seems your use case is well-captured by the react-refetch package which you can find here. It provides a higher-order component that allows you to specify dependencies at specific API endpoints and then resolves them when a new instance of your component is created.
Importantly it injects the data into your components props using a synchronous abstraction of a promise called a PromiseState. This will allow you to conditionally render your component depending on whether the data is say pending, fulfilled, rejected, etc.
This is not attached in any way to Redux, it skips that layer entirely, so do keep it in mind that the response is directly injected into the component and does not go through your redux store's state.
I've been learning Redux and a part I'm unclear of is, how do I make a determination between using react state vs redux store and then dispatching actions. from my reading so far it looks like I could use React state in place of Redux store and still get things done. I understand the separation of concerns with using Redux store and just having 1 container component and the rest of it as stateless component but how do I make the determination of when to use React state Vs redux store is not very clear to me. Can someone please help?
Thanks!
If the state doesn't need to be shared with other components, or the state doesn't need to be keep when the component is unmounted, then you can just put it in the component's state.
You can think that the Redux store is the database of front-end, if you have something like product data fetched from an API, then the Redux store is the right place; if you have a dropdown component, which takes a isOpen prop, then the parent of that dropdown can just keep dropdownIsOpen as a component state.
For more information, here is the answer from Dan: https://github.com/reactjs/redux/issues/1287
Also you said
only 1 container component and the rest of it as stateless component
This is incorrect. You can have several container components. A container component can also contain another container component.
From book:
First of all, we should always keep in mind that only the minimal
amount of data needed should be put into the state. For example, if we
have to change a label when a button is clicked we should not store
the text of the label, but we should only save a Boolean flag that
tells us if the button has been clicked or not. Secondly, we should
add to the state only the values that we want to update when an event
happens, and for which we want to make the component re-render.
Another way to figure out whether the state is the right place to
store information is to check if the data we are persisting is needed
outside the component itself or by its children. If multiple
components need to keep track of the same information, we should
consider using a state manager like Redux at the application level.
There are a few things that need to be grasp
State of component: If you want to keep state-specific to your HOC then use state. Now in the function component, we use useState.
State of redux: If you want to share data throughout the application use redux state.
Store of redux: It's nothing but a database for the redux library. In the case of redux, we can have only one store. To use multiple stores we can use Flux but it will make things more complicated.
You're absolutely right. Redux (and flux architecture in general) are only formalism tools to help for building large apps. They're not necessary at all.
There's actually an interesting post called You might not need redux by Dan Abramov, the creator of redux that might give you a better answer than I do: https://medium.com/#dan_abramov/you-might-not-need-redux-be46360cf367#.7093fm1z8
If state is needed only for that particular component then prefer to use react state.
For example using state for UI actions
If any state you want to use across the component/project then go with redux state.
For example API response data etc
For detail understanding refer this link
https://spin.atomicobject.com/2017/06/07/react-state-vs-redux-state/
I have a react native project and I am using redux actions and reducers to handle my store.
I have a smart connected component and I call my actions through dispatch in componentWillMount() and then I have mapStateToProps and I map the data I get from my store to props.
Problem is the only way to check if the props are changed, is by putting it inside render function. In my case I want to navigate to another page if I get props filled with some data. It all works fine but I get warning from React that its anti pattern. Is there any other way of doing this? Am I doing it right?
You should implement the method componentWillReceiveProps instead of comparing the values in the render
Another (preferable) approach would be the action responsible to update the values, do the navigation (or dispatch another actions that would do the navigation stuff). Check redux-thunk