react-async-comp
v0.2.11
Published
RAC is a library used for rendering components with asynchronous data.
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React Async Component
RAC is a library used for rendering components with asynchronous data.
Getting started
Installation
Using npm
npm i react-async-comp
Using yarn
yarn add react-async-comp
Quick Start Guide
import { Suspense } from "react";
import { ErrorBoundary } from "react-error-boundary";
import { view } from "react-async-comp";
const TodoList = view(async () => {
// fetching data
const res = await fetch("https://jsonplaceholder.typicode.com/todos");
const todos = await res.json();
// rendering
return (
<ul>
{todos.map((todo) => (
<li key={todo.id}>{todo.title}</li>
))}
</ul>
);
});
const App = () => {
return (
<>
<ErrorBoundary fallback={<div>Something went wrong</div>}>
<Suspense fallback={<div>Loading...</div>}>
{/* Even if the component has multiple instances, the data fetching code runs only once */}
<TodoList />
<TodoList />
<TodoList />
</Suspense>
</ErrorBoundary>
</>
);
};
In the example above, we can use asynchronous data fetching code alongside rendering code. There are important rules to note:
- Do not use any React hooks inside the data loading function.
- All component properties must be serializable. Accepted types include: Boolean, String, null, undefined, number, RegExp, Date, PlainObject, and Array.
- RAC must be used in conjunction with the
Suspense
andErrorBoundary
components.
Advanced Usages
Using hook with RAC
To use hooks with React Async Component, the view(loader, render)
overload must be utilized. The render
function accepts component props and RenderContext
as parameters. RenderContext
consists of the following properties:
revalidate
: Triggers a revalidation for all instances of the component.data
: Represents the data fetched by theloader()
function.
const TodoList = view(
// loader function
async () => {
const res = await fetch("https://jsonplaceholder.typicode.com/todos");
const todos = await res.json();
return todos;
},
// render function
(props, { data: todos, revalidate }) => {
// consume hooks or contexts
const [state, setState] = useState();
const store = useStore();
// render function can accept non-serializable
const handleClick = props.onClick;
return (
<ul>
{todos.map((todo) => (
<li onClick={handleClick} key={todo.id}>
{todo.title}
</li>
))}
</ul>
);
}
);
RAC data lifecycle
By default, RAC automatically disposes of fetched data if it is no longer used by any components.
const App = () => {
const [show, setShow] = useState(true);
return (
<>
<button onClick={() => setShow(!show))>Toggle todo list</button>
{show && <ErrorBoundary fallback={<div>Something went wrong</div>}>
<Suspense fallback={<div>Loading...</div>}>
<TodoList />
</Suspense>
</ErrorBoundary>}
</>
);
};
When the TodoList
is toggled, the todo list data will be disposed if TodoList is unmounted and will be refetched when TodoList
is mounted again.
To retain the fetched data indefinitely, the following options can be utilized:
const TodoList = view(loader, { dispose: "never" });
The dispose
option accepts two values: never
and unused
:
never
: The fetched data is never removed.unused
(default): The fetched data will be removed when it is no longer used by any RAC.
Revalidating RAC data
Revalidating RAC data involves re-executing the loader
function and performing a re-render of all RAC instances that consume the data.
To revalidate RAC data, you can use one of the following approaches:
- Utilize the
revalidate
method from LoaderContext, which is the second argument of the loader function. - Employ the
revalidate
method from RenderContext, provided as the second argument of the render function. - Invoke the
revalidate
method directly on the RAC.
// using revalidate method of LoaderContext
const TodoList = view((props, { revalidate }) => {
return (
<>
<button onClick={revalidate} />
</>
);
});
const TodoList = view(
(props) => todoList,
// using revalidate methods of RenderContext
(props, { revalidate }) => {
return (
<>
<button onClick={revalidate} />
</>
);
}
);
// using static revalidate method of RAC
TodoList.revalidate();
Using RAC with external stores
RAC can integrate with external stores, utilizing their data and revalidating whenever the store data changes.
import { store } from "./redux-store";
const TodoList = view((props, { use }) => {
// When the store state is updated, the loader function will be invoked.
const { filter } = use(store);
const todos = await getTodosWithFilter(filter)
return (<>
<ul>
{todos.map((todo) => (
<li key={todo.id}>
{todo.title}
</li>
))}
</ul>
</>);
});