react

Galaxis React

React bindings for Galaxis.

Installation

yarn add @galaxis/react

This will also install and expose API of Galaxis Core.

The library is compiled to modern JS, but it should work in all reasonable browsers with the help of properly configured Babel.

Your client environment has to have AbortController. You might need to polyfill it.

You also need a version of React that supports React Hooks.

Public API

⚠ Anything that is not documented here is not considered a part of public API and may change at any time.

ClientProvider

ClientProvider is used to configure and provide a Client instance for the rest of the application.

interface AppProps {
    client: AppClient;
}

const App: FC<AppProps> = ({ client }) => (
    <ClientProvider client={client}>
        <RestOfTheApp />
    </ClientProvider>
);

Arguments

ClientProviderProps

Name	Type	Description	Required
client	Client	A Client instance that will be used by the application.	Yes
preventOnHydrateCompleteCall	boolean	By default, client.onHydrateComplete() will be called in useEffect. It should be fine in most cases, but you can use this option as an escape hatch and call client.onHydrateComplete() manually.	No

useClient()

useClient is used to retrieve the Client instance that was passed to the Provider. You can then use it to execute queries and mutations manually, access cache, etc.

const MyComponent: FC = () => {
    const client = useClient();

    const onClick = () => {
        client.fetchQuery(query).then((data) => console.log(data));
    };

    return <button onClick={onClick}>Fetch the query manually</button>;
};

useQuery()

useQuery is a thin wrapper for ObservableQuery.

On rerender, the Query objects fields are shallowly compared by the following rules:

• The query.resource fields are compared by the result of the client.requestId() call.
• Functions are compared by their .toString() representation.
• Everything else is compared by strict equality (===).

const MyComponent: FC = () => {
    const { data } = useQuery(query);

    return <div>{data?.value}</div>;
};

Arguments

Name	Type	Description	Required
query	Query	A query to maintain.	No

Return value

ObservableQueryState & {refetch: observableQuery.refetch}

useMutation()

useMutation is a thin wrapper for ObservableMutation.

On rerender, the Mutation object is just reassigned, because it doesn't lead to any side effects.

const MyComponent: FC = () => {
    const [execute, state] = useMutation(mutation);

    return <button onClick={execute}>Execute the mutation</button>;
};

Arguments

Name	Type	Description	Required
mutation	Mutation	A mutation to maintain.	No

Return value

Name	Type	Description
execute	(mutation?: Mutation) => Promise<TData>	A function for mutation execution.
state	ObservableMutationState & {reset: observableMutation.reset}	Mutation state and reset function.

getDataFromTree()

getDataFromTree() is used on the server side to wait for queries to fill the cache with data and errors.

export default async function ssrMiddleware(_: Request, res: Response<unknown>) {
    const client = getClient();

    const app = createElement(App, { client });

    await getDataFromTree(app);

    const galaxisState = client.getCache().extract();

    const html = createElement(Html, { content: renderToString(app), galaxisState });

    res.send(renderToStaticMarkup(html));
}

Arguments

Name	Type	Description	Required
tree	ReactNode	The application.	Yes

Return value

Promise<string>. The promise resolves with the result of renderToStaticMarkup() call.