- Lightweight
- Easy to use
- Easy to integrate with Axios, fetch, or any Promise-based tool
$ pnpm add @scaleway/use-dataloader
Firstly you need to put the context at the top of your App.
import { DataLoaderProvider } from '@scaleway-lib/use-dataloader'
import React from 'react'
import ReactDOM from 'react-dom'
import App from './App'
ReactDOM.render(
<React.StrictMode>
<DataLoaderProvider>
<App />
</DataLoaderProvider>
</React.StrictMode>,
document.getElementById('root'),
)
Now you can use useDataLoader
and useDataLoaderContext
in your App
You can specify a global cacheKeyPrefix
which will be inserted before each cache key
This can be useful if you have a global context (eg: if you can switch account in your app, ...)
import { DataLoaderProvider, useDataLoader } from '@scaleway-lib/use-dataloader'
import React from 'react'
import ReactDOM from 'react-dom'
const App = () => {
useDataLoader('cache-key', () => 'response') // Real key will be prefixed-cache-key
return null
}
ReactDOM.render(
<React.StrictMode>
<DataLoaderProvider onError={globalOnError} cacheKeyPrefix="prefixed">
<App />
</DataLoaderProvider>
</React.StrictMode>,
document.getElementById('root'),
)
You can specify a maxConcurrentRequests
which will prevent DataLoader to launch request simultaneously and wait some to finish before start next ones.
This can be useful if you want to limit the number of concurrent requests.
This is a global onError
handler. It will be overriden if you specify one in useDataLoader
import { DataLoaderProvider, useDataLoader } from '@scaleway-lib/use-dataloader'
import React from 'react'
import ReactDOM from 'react-dom'
const failingPromise = async () => {
throw new Error('error')
}
const App = () => {
useDataLoader('local-error', failingPromise, {
onError: error => {
console.log(`local onError: ${error}`)
},
})
useDataLoader('error', failingPromise)
return null
}
const globalOnError = error => {
console.log(`global onError: ${error}`)
}
ReactDOM.render(
<React.StrictMode>
<DataLoaderProvider onError={globalOnError}>
<App />
</DataLoaderProvider>
</React.StrictMode>,
document.getElementById('root'),
)
import { useDataLoader } from '@scaleway-lib/use-dataloader'
const fakePromise = () =>
new Promise(resolve => setTimeout(resolve('test'), 1000))
function MyComponent() {
// Use a key if you want to persist data in the DataLoaderProvider cache
const { data, isLoading, isSuccess, isError, error } = useDataLoader(
'cache-key',
fakePromise,
)
// This is the first time we load the data
if (isLoading && !data) {
return <div>Loading...</div>
}
// This happen when you already load the data but want to reload it
if (isLoading && data) {
return <div>Reloading...</div>
}
// Will be true when the promise is resolved
if (isSuccess) {
// Will display "test" in the the div
return <div>{data}</div>
}
// Will be false when the promise is rejected
if (isError) {
// Will display the error in the the div
return <div>{error}</div>
}
}
export default MyComponent
import { useDataLoaderContext } from '@scaleway-lib/use-dataloader'
const fakePromise = () =>
new Promise(resolve => {
setTimeout(resolve('test'), 1000):
})
function MyComponentThatUseDataLoader({key}) {
// Use a key if you want to persist data in the DataLoaderProvider cache
const { data, isLoading, isSuccess, isError, error } = useDataLoader(
key,
fakePromise,
)
// Will be true during the promise
if (isLoading) {
return <div>Loading...</div>
}
// Will be true when the promise is resolved
if (isSuccess) {
// Will display "test" in the the div
return <div>{data}</div>
}
// Will be false when the promise is rejected
if (isError) {
// Will display the error in the the div
return <div>{error}</div>
}
}
function MyComponent() {
const { reloadAll, reload } = useDataLoaderContext();
const handleReload = (keyToReload) => () => {
await reload(keyToReload) // Execute the method
}
}
const handleReloadAll = () => {
await reloadAll()
}
}
return (
<div>
<MyComponentThatUseDataLoader key="test" />
<MyComponentThatUseDataLoader key="test-2" />
<button onClick={handleReload("test")}>Reload first</button>
<button onClick={handleReload("test-2")}>Reload second</button>
<button onClick={handleReloadAll}>Reload all</button>
</div>
)
}
export default MyComponent
const useDataLoader = (
key, // A key to save the data fetched in a local cache
method, // A method that return a promise (ex: () => new Promise((resolve) => setTimeout(resolve, 2000))
{
onSuccess, // Callback when a request success
onError, // Callback when a error is occured
initialData, // Initial data if no one is present in the cache before the request
pollingInterval, // Relaunch the request after the last success
needPolling = true, // If true or function return true it will execute the polling
enabled = true, // Launch request automatically
keepPreviousData = true, // Do we need to keep the previous data after reload
dataLifetime, // Max time before previous success data is outdated (in millisecond). By default refetch on every mount
} = {},
)
Property | Description |
---|---|
isIdle | true if the request is not launched |
isLoading | true if the request is launched or enabled is true and isIdle is true |
isSuccess | true if the request finished successfully |
isError | true if the request throw an error |
isPolling | true if the request if enabled is true, pollingInterval is defined and the status is isLoading ,isSuccess or during the first fetch |
previousData | if keepPreviousData is true it return the last data fetched |
data | return the initialData if no data is fetched or not present in the cache otherwise return the data fetched |
error | return the error occured during the request |
reload | allow you to reload the data (it doesn't clear the actual data) |