useCheckpoints
The useCheckpoints hook is used to get a reference to a Checkpoints object from within a Provider component context.
useCheckpoints(id?: any): Checkpoints | undefined| Type | Description | |
|---|---|---|
id? | any | An optional |
| returns | Checkpoints | undefined | A reference to the |
A Provider component is used to wrap part of an application in a context. It can contain a default Checkpoints object (or a set of Checkpoints objects named by Id) that can be easily accessed without having to be passed down as props through every component.
The useCheckpoints hook lets you either get a reference to the default Checkpoints object (when called without a parameter), or one of the Checkpoints objects that are named by Id (when called with an Id parameter).
Examples
This example creates a Provider context into which a default Checkpoint object is provided. A component within it then uses the useCheckpoints hook to get a reference to the Checkpoints object again, without the need to have it passed as a prop.
const App = ({checkpoints}) => (
<Provider checkpoints={checkpoints}>
<Pane />
</Provider>
);
const Pane = () => (
<span>{useCheckpoints().getListenerStats().checkpointIds}</span>
);
const checkpoints = createCheckpoints(createStore());
const app = document.createElement('div');
const root = ReactDOMClient.createRoot(app);
root.render(<App checkpoints={checkpoints} />);
console.log(app.innerHTML);
// -> '<span>0</span>'
This example creates a Provider context into which a Checkpoints object is provided, named by Id. A component within it then uses the useCheckpoints hook with that Id to get a reference to the Checkpoints object again, without the need to have it passed as a prop.
const App = ({checkpoints}) => (
<Provider checkpointsById={{petStore: checkpoints}}>
<Pane />
</Provider>
);
const Pane = () => (
<span>
{useCheckpoints('petStore').getListenerStats().checkpointIds}
</span>
);
const checkpoints = createCheckpoints(createStore());
const app = document.createElement('div');
const root = ReactDOMClient.createRoot(app);
root.render(<App checkpoints={checkpoints} />);
console.log(app.innerHTML);
// -> '<span>0</span>'