`useCell`

The useCell hook returns an object containing the value of a single Cell in a given Row, in a given Table, and registers a listener so that any changes to that result will cause a re-render.

useCell(
  tableId: Id,
  rowId: Id,
  cellId: Id,
  storeOrStoreId?: any,
): CellOrUndefined

	Type	Description
`tableId`	`Id`	The `Id` of the `Table` in the `Store`.
`rowId`	`Id`	The `Id` of the `Row` in the `Table`.
`cellId`	`Id`	The `Id` of the `Cell` in the `Row`.
`storeOrStoreId?`	`any`	The `Store` to be accessed: omit for the default context `Store`, provide an `Id` for a named context `Store`, or provide an explicit reference.
returns	`CellOrUndefined`	The value of the `Cell`.

A Provider component is used to wrap part of an application in a context, and it can contain a default Store or a set of Store objects named by Id. The useCell hook lets you indicate which Store to get data for: omit the final optional final parameter for the default context Store, provide an Id for a named context Store, or provide a Store explicitly by reference.

When first rendered, this hook will create a listener so that changes to the Cell will cause a re-render. When the component containing this hook is unmounted, the listener will be automatically removed.

Examples

This example creates a Store outside the application, which is used in the useCell hook by reference. A change to the data in the Store re-renders the component.

const store = createStore().setCell('pets', 'fido', 'color', 'brown');
const App = () => <span>{useCell('pets', 'fido', 'color', store)}</span>;

const app = document.createElement('div');
ReactDOMClient.createRoot(app).render(<App />);
console.log(app.innerHTML);
// -> '<span>brown</span>'

store.setCell('pets', 'fido', 'color', 'walnut');
console.log(app.innerHTML);
// -> '<span>walnut</span>'

This example creates a Provider context into which a default Store is provided. A component within it then uses the useCell hook.

const App = ({store}) => (
  <Provider store={store}>
    <Pane />
  </Provider>
);
const Pane = () => <span>{useCell('pets', 'fido', 'color')}</span>;

const store = createStore().setCell('pets', 'fido', 'color', 'brown');
const app = document.createElement('div');
ReactDOMClient.createRoot(app).render(<App store={store} />);
console.log(app.innerHTML);
// -> '<span>brown</span>'

This example creates a Provider context into which a Store is provided, named by Id. A component within it then uses the useCell hook.

const App = ({store}) => (
  <Provider storesById={{petStore: store}}>
    <Pane />
  </Provider>
);
const Pane = () => (
  <span>{useCell('pets', 'fido', 'color', 'petStore')}</span>
);

const store = createStore().setCell('pets', 'fido', 'color', 'brown');
const app = document.createElement('div');
ReactDOMClient.createRoot(app).render(<App store={store} />);
console.log(app.innerHTML);
// -> '<span>brown</span>'