useRelationshipsOrRelationshipsById
The useRelationshipsOrRelationshipsById
hook is used to get a reference to a Relationships
object from within a Provider
component context, or have it passed directly to this hook.
useRelationshipsOrRelationshipsById(relationshipsOrRelationshipsId?: RelationshipsOrRelationshipsId): Relationships | undefined
Type | Description | |
---|---|---|
relationshipsOrRelationshipsId? | RelationshipsOrRelationshipsId | Either an |
returns | Relationships | undefined | A reference to the |
This is mostly of use when you are developing a component that needs a Relationships
object and which might have been passed in explicitly to the component or is to be picked up from the context by Id
(a common pattern for Relationships
-based components).
This is unlikely to be used often. For most situations, you will want to use the useRelationships
hook.
Example
This example creates a Provider context into which a default Relationships
object is provided. A component within it then uses the useRelationshipsOrRelationshipsById
hook to get a reference to the Relationships
object again, without the need to have it passed as a prop. Note however, that unlike the useRelationships
hook example, this component would also work if you were to pass the Relationships
object directly into it, making it more portable.
import React from 'react';
import {createRoot} from 'react-dom/client';
import {createRelationships, createStore} from 'tinybase';
import {
Provider,
useRelationshipsOrRelationshipsById,
} from 'tinybase/ui-react';
const App = ({relationships}) => (
<Provider relationships={relationships}>
<Pane />
</Provider>
);
const Pane = ({relationships}) => (
<span>
{JSON.stringify(
useRelationshipsOrRelationshipsById(
relationships,
).getRelationshipIds(),
)}
</span>
);
const relationships = createRelationships(
createStore()
.setTable('pets', {fido: {species: 'dog'}, cujo: {species: 'dog'}})
.setTable('species', {wolf: {price: 10}, dog: {price: 5}}),
).setRelationshipDefinition('petSpecies', 'pets', 'species', 'species');
const app = document.createElement('div');
const root = createRoot(app);
root.render(<App relationships={relationships} />);
console.log(app.innerHTML);
// -> '<span>["petSpecies"]</span>'
Since
v4.1.0