Relay integration for React Router.
This library only supports Relay Classic. For Relay Modern support, see Found Relay.
This library does not support React Router v4, because React Router v4 does not provide the necessary integration points for efficient data fetching with Relay. Additionally, rendering performance will be better with React Router v2 than with React Router v3, as the link subscription logic in React Router v3 triggers unnecessary rerenders with Relay.
Usage
Apply the useRelay
router middleware, pass in a Relay environment to <Router>
, then define Relay queries and render callbacks for each of your routes:
import { applyRouterMiddleware, /* ... */ } from 'react-router';
import useRelay from 'react-router-relay';
/* ... */
const ViewerQueries = {
viewer: () => Relay.QL`query { viewer }`
};
const WidgetQueries = {
widget: () => Relay.QL`query { widget(widgetId: $widgetId) }`
}
ReactDOM.render(
<Router
history={history}
render={applyRouterMiddleware(useRelay)}
environment={Relay.Store}
>
<Route
path="/"
component={Application}
queries={ViewerQueries}
>
<Route path="widgets">
<IndexRoute
component={WidgetList}
queries={ViewerQueries}
prepareParams={prepareWidgetListParams}
/>
<Route
path=":widgetId"
component={Widget}
queries={WidgetQueries}
render={({ props }) => props ? <Widget {...props} /> : <Loading />}
/>
</Route>
</Route>
</Router>,
container
);
react-router-relay
will automatically generate a combined Relay query config with all queries and parameters from the active React Router routes, then pass down the query results to each of the route components. As the queries are all gathered onto a single query config, they'll all be fetched in parallel, and the data for your entire page will load and then render in one go.
You can find an example implementation of TodoMVC with routing using react-router-relay
at https://github.com/taion/relay-todomvc.
Guide
Installation
$ npm install react react-dom react-relay react-router
$ npm install react-router-relay
Router configuration
Apply the useRelay
router middleware, and pass in a Relay environment to the <Router>
:
import useRelay from 'react-router-relay';
/* ... */
ReactDOM.render(
<Router
history={history}
routes={routes}
render={applyRouterMiddleware(useRelay)}
environment={Relay.Store}
/>,
container
);
Routes and queries
Basic configuration
For each of your routes that requires data from Relay, define a queries
prop on the <Route>
. These should be just like the queries on a Relay query config:
const ViewerQueries = {
viewer: () => Relay.QL`query { viewer }`
};
const applicationRoute = (
<Route
path="/"
component={Application}
queries={ViewerQueries}
/>
);
Just like with Relay.Renderer
, the component will receive the query results as props, in addition to the other injected props from React Router.
If your route doesn't have any dependencies on Relay data, just don't declare queries
. The only requirement is that any route that does define queries
must have a Relay container as its component.
If your route's Relay data dependencies are a function of the location or of the parameters, you can define a getQueries
function on your route that returns the computed queries as a function of the current router state:
<Route
component={Widget}
getQueries={({ location, params }) => getWidgetQueries(location, params)}
/>
Path parameters
Any path parameters for routes with queries and their ancestors will be used as parameters on the Relay query config:
const WidgetQueries = {
widget: () => Relay.QL`
query {
widget(widgetId: $widgetId), # $widgetId comes from the path.
}
`
}
const Widget = Relay.createContainer(/* ... */, {
fragments: {
widget: () => Relay.QL`
fragment on Widget {
name,
}
`
}
});
// This handles e.g. /widgets/3.
const widgetRoute = (
<Route
path="widgets/:widgetId"
component={Widget}
queries={WidgetQueries}
/>
);
Additional parameters
If your queries require additional parameters from the location, such as from the location query or state, you can add those parameters with prepareParams
. You can also use prepareParams
to do additional conversion or initialization of your parameters.
The prepareParams
method has the same signature and behavior as prepareParams
on a Relay query config, except that it also receives the current router state as an argument. It is expected to return the same result when given the same previous params and router state.
Additionally, you can use route parameters as variables on your containers:
const WidgetList = Relay.createContainer(/* ... */, {
initialVariables: {
color: null,
size: null,
limit: null
},
fragments: {
viewer: () => Relay.QL`
fragment on User {
widgets(color: $color, size: $size, first: $limit) {
edges {
node {
name,
},
},
},
}
`
}
});
function prepareWidgetListParams(params, { location }) {
const { color, size } = location.query;
const limit = location.state && location.state.limit;
return {
...params,
color,
size: size && parseInt(size, 10),
limit: limit || 10,
};
};
// This handles e.g. /widgets?color=blue&size=3.
const widgetListRoute = (
<Route
path="widgets"
component={WidgetList}
queries={ViewerQueries}
prepareParams={prepareWidgetListParams}
/>
);
Named components
For routes with named components, define queries
as an object with the queries for each component by name:
<Route
components={{ foo: FooComponent, bar: BarComponent }}
queries={{ foo: FooQueries, bar: BarQueries }}
/>
Render callback
You can pass in a custom render
callback to your routes:
<Route
component={WidgetList}
queries={ViewerQueries}
render={({ props }) => props ? <WidgetList {...props} /> : <Loading />}
/>
This has the same signature as the render
callback on Relay.Renderer
, except that, when present, props
will also include the injected props from React Router. As on Relay.Renderer
, you can return undefined
to continuing rendering the last view rendered.
While transitioning, the ready state properties (done
, error
, retry
, stale
) will reflect the ready state of the transition as a whole. However, the props
object in the render
callback for a route will be populated as long as the data for that particular route are ready. For example, if a transition does not change the params to the queries for a parent route, the render
callback for that route will have props
, even while the render
callbacks for its child routes may not.
The argument object to the render callback includes two extra properties: routerProps
and element
. routerProps
contains the props from the router, and unlike props
, will be populated regardless of the Relay ready state. routerProps
can be used to render child routes while the data for the parent route are still loading, or to otherwise use information from the router to control rendering before the Relay data are available. element
contains the base route element without the props from Relay, and can be used to render the route component when the route uses a dynamic component, or when using other router middlewares that may wrap the route component:
({ props, routerProps, element }) => {
if (!props) {
return <Loading {...routerProps} />;
}
return React.cloneElement(element, props);
}
When using named components, you can define these on a per-component basis, optionally omitting the callback for components that do not need a custom render callback:
<Route
components={{ foo: FooComponent, bar: BarComponent }}
queries={{ foo: FooQueries, bar: BarQueries }}
render={{ foo: renderFoo }}
/>
Relay.Renderer
configuration
Additional We pass through additional props on <Router>
or the generated router context to the underlying Relay.Renderer
. You can use this to control props like forceFetch
on the Relay.Renderer
:
<Router
history={history}
routes={routes}
render={applyRouterMiddleware(useRelay)}
forceFetch={true}
environment={Relay.Store}
/>
Notes
- The default Relay network layer executes each query as a separate network request. If you want to execute all of your queries in a single request, then you will need to use a custom network layer that can send multiple queries in the same request, along with a GraphQL server that can execute multiple queries from a single request.
react-router-relay
uses referential equality on route objects to generate unique names for queries. If yourroute
objects do not maintain referential equality, then you can specify a globally uniquename
property on the route to identify it.- Relay's re-rendering optimizations only work when all non-Relay props are scalar. As the props injected by React Router are objects, they disable these re-rendering optimizations. To take maximum advantage of these optimizations, you should make the
render
methods on your route components as lightweight as possible, and do as much rendering work as possible in child components that only receive scalar and Relay props.