DOC : https://vikyw89.github.io/useSyncV/
NPM: https://www.npmjs.com/package/use-sync-v
GH: https://github.com/vikyw89/useSyncV
breaking change on v3
Why use sync v ?
- in front all we want is to get synced data from backend
- recreating database in front end in a global state is tedious
- just subscribe to the data that we need, that we can access anywhere in front end
- opinionated
npm i use-sync-v
- You want to have a global store that fetch data from backend
- everytime you modify the backend data, useAsyncSubV will refetch the data for you
- we use stale data while refetching by default
- loading and data state can both be true at the same time
- when the component is dismounted, all fetched data will be erased
const asyncFn = async () => {
const response = await fetch('https://randomuser.me/api/');
const data = await response.json();
return data;
};
export const UseAsyncSubVTest = () => {
// this will subscribe this component to 'randomUser', whenever we do setAsyncFn with 'randomUser' as selector, the data will refetch
const { data, loading, error } = useAsyncSubV('randomUser', asyncFn);
const refetchHandler = async () => {
// we want to modify backend data
asyncRefetchV('randomUser', async (p) => {
// we can set the data here for optimistic rendering (optional)
setSyncV('randomUser', someDataForOptimisticRendering);
// we can put function here to post / modify data in backend database
await insertDataToRandomUserTable();
// useAsyncSubV will automatically refetch data
});
};
return (
<div>
{loading && <div>Loading</div>}
{data && <div>{JSON.stringify(data)}</div>}
{error && <div>error</div>}
<button onClick={refetchHandler}>refetch</button>
</div>
);
};
// let's say we have another component that we want to use the data from 'randomUser'
export const AnotherComponent = () => {
// access data from 'randomUser' earlier
const { data, loading, error } = useAsyncV('randomUser');
return (
<div>
{loading && <div>Loading</div>}
{data && <div>{JSON.stringify(data)}</div>}
{error && <div>error</div>}
<button onClick={refetchHandler}>refetch</button>
</div>
);
};
export const AsyncSubTest = () => {
const {data, loading, error} = useAsyncV('random')
useEffect(()=>{
// set up subscription
// then modify state data with
setAsyncV('random', dataReturnedFromSubscription)
// this way, everytime there's a new data sent from backend, it will automatically stored to 'random' state
},[])
}
setSyncV('counter', 0);
// create a counter state with initial value of 0
// this is not a hook, you can call the function anywhere
setSyncV('counter', (p) => p 1);
// this will increment counter state by 1
setSyncV('data', [
{
name: 'Irene'
},
{
name: 'Irenelle'
}
]);
// this will store an Array of Object into "data" state
Updating a deeply nested object is easy
setSyncV('data[0].phone_number', '010039945');
// this will add phone number field to the first object in our Array under the name Irene
getSyncV('data[0]');
// => {
// name:'Irene',
// phone_number:'010039945'
// }
export const CounterDisplayComponent = () => {
const data = useSyncV('data[0]');
// sync this component to "data[0]" state, will re render component whenever the value of "data[0]" state changes
};
setSyncV(selector:string, updates:function(previousValue) || value)
// to update the value of the state selector using an updater function or a value
// the updater function take a parameter (original state) and return a value (updated state)
// if given a value, it will replace existing value with the value
useSyncV(selector:string)
// to subscribe to the state selector, and will re render the component whenever the value change
// be specific in the selector to prevent unnecessary rerendering
- with backend without built in subscription
useAsyncSubV(selector:string, asyncFn:function, config?:obj)
// to subscribe to backend
useAsyncV(selector:string, config?:object)
// will subscribe to the selector, and if there's no existing data, it will prepopulate it with {loading, data, error} initial state
asyncRefetchV(selector:string, asyncFn:function, config?:object)
// to fetch a data from api, save the results into the store
- with backend with built in subscription like Firestore
useAsyncV(selector:string)
// to listen to asyncData
setAsyncV(selector:string, asyncFn:function, config?:object)
//
for more explanation: look at the code snippet