pr_01m47d24b0e6n91zwymwxg0vpx/apps/web/.agents/skills/react-router/references/data-mode.md
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| Initial g1t: services, event bus, intents and attempts | 1 | # Data Mode |
| 2 | ||
| 3 | Data Mode uses data routers such as `createBrowserRouter` and renders with `<RouterProvider>`. It gives an app route objects, loaders, actions, pending UI, fetchers, and SSR primitives without adopting the Framework Vite plugin or route-module file conventions. | |
| 4 | ||
| 5 | Use this reference after the main skill identifies a Data Mode app. | |
| 6 | ||
| 7 | ## Read the Local Docs by Mode | |
| 8 | ||
| 9 | Start with: | |
| 10 | ||
| 11 | ```txt | |
| 12 | react-router/docs/start/modes.md | |
| 13 | react-router/docs/start/data/index.md | |
| 14 | ``` | |
| 15 | ||
| 16 | Then use the Data docs under: | |
| 17 | ||
| 18 | ```txt | |
| 19 | react-router/docs/start/data/ | |
| 20 | ``` | |
| 21 | ||
| 22 | Those files cover installation, route objects, routing, data loading, actions, navigation, pending UI, and testing. For task-specific details, read relevant files in: | |
| 23 | ||
| 24 | ```txt | |
| 25 | react-router/docs/how-to/ | |
| 26 | react-router/docs/explanation/ | |
| 27 | ``` | |
| 28 | ||
| 29 | Always check the `[MODES: data, ...]` marker in a doc before applying it. | |
| 30 | ||
| 31 | ## Data Router Shape | |
| 32 | ||
| 33 | Typical setup: | |
| 34 | ||
| 35 | ```tsx | |
| 36 | import { createBrowserRouter, RouterProvider } from "react-router"; | |
| 37 | ||
| 38 | const router = createBrowserRouter([ | |
| 39 | { | |
| 40 | path: "/", | |
| 41 | Component: Root, | |
| 42 | loader: rootLoader, | |
| 43 | children: [ | |
| 44 | { index: true, Component: Home }, | |
| 45 | { | |
| 46 | path: "projects/:projectId", | |
| 47 | Component: Project, | |
| 48 | loader: projectLoader, | |
| 49 | }, | |
| 50 | ], | |
| 51 | }, | |
| 52 | ]); | |
| 53 | ||
| 54 | root.render(<RouterProvider router={router} />); | |
| 55 | ``` | |
| 56 | ||
| 57 | Look for route object arrays and APIs such as: | |
| 58 | ||
| 59 | - `createBrowserRouter` | |
| 60 | - `createHashRouter` | |
| 61 | - `createMemoryRouter` | |
| 62 | - `RouterProvider` | |
| 63 | - `loader` | |
| 64 | - `action` | |
| 65 | - `Component` | |
| 66 | - `ErrorBoundary` | |
| 67 | - `lazy` | |
| 68 | - `children` | |
| 69 | ||
| 70 | ## Route Objects and Routing | |
| 71 | ||
| 72 | Before editing route configuration, read: | |
| 73 | ||
| 74 | ```txt | |
| 75 | react-router/docs/start/data/routing.md | |
| 76 | react-router/docs/start/data/route-object.md | |
| 77 | ``` | |
| 78 | ||
| 79 | Rules: | |
| 80 | ||
| 81 | - Keep route objects outside render when possible. | |
| 82 | - Use nested routes for shared layouts and data boundaries. | |
| 83 | - Use index routes for default child content. | |
| 84 | - Use dynamic segments and splats according to route-object docs. | |
| 85 | - Prefer `Component`/`ErrorBoundary` route object properties in Data Mode examples unless the existing app uses `element` consistently. | |
| 86 | ||
| 87 | ## Data and Mutations | |
| 88 | ||
| 89 | Before working on data loading or mutations, read: | |
| 90 | ||
| 91 | ```txt | |
| 92 | react-router/docs/start/data/data-loading.md | |
| 93 | react-router/docs/start/data/actions.md | |
| 94 | ``` | |
| 95 | ||
| 96 | Rules: | |
| 97 | ||
| 98 | - Load route data with route `loader` functions. | |
| 99 | - Mutate route data with route `action` functions. | |
| 100 | - Prefer loaders/actions over route-level `useEffect` fetching. | |
| 101 | - Use `request`, `params`, and returned/throwable Responses as described in the docs. | |
| 102 | - Let React Router revalidate after actions unless there is a documented reason to customize revalidation. | |
| 103 | ||
| 104 | Common patterns: | |
| 105 | ||
| 106 | - Validation failure from an action: return `data({ errors, values }, { status: 400 })`, then render errors with `useActionData()` or `fetcher.data`. | |
| 107 | - Missing record in a loader: throw `data("Not Found", { status: 404 })` and render the route `ErrorBoundary`. | |
| 108 | - Search/filter data: parse `new URL(request.url).searchParams` in the loader so the URL is shareable and bookmarkable. | |
| 109 | ||
| 110 | ## Forms, Fetchers, and Pending UI | |
| 111 | ||
| 112 | For forms and pending UI, read: | |
| 113 | ||
| 114 | ```txt | |
| 115 | react-router/docs/start/data/actions.md | |
| 116 | react-router/docs/start/data/pending-ui.md | |
| 117 | react-router/docs/how-to/fetchers.md | |
| 118 | react-router/docs/explanation/form-vs-fetcher.md | |
| 119 | ``` | |
| 120 | ||
| 121 | Rules of thumb: | |
| 122 | ||
| 123 | - Search/filter form that updates the URL: `<Form method="get">`. | |
| 124 | - Mutation that should change URL/history or redirect after completion: `<Form method="post">`. | |
| 125 | - Mutation that should keep the user on the same page: `useFetcher` / `<fetcher.Form>`. | |
| 126 | - Optimistic UI: derive from `fetcher.formData` or `navigation.formData`. | |
| 127 | ||
| 128 | ## Navigation and URL State | |
| 129 | ||
| 130 | Before changing navigation or search params, read: | |
| 131 | ||
| 132 | ```txt | |
| 133 | react-router/docs/start/data/navigating.md | |
| 134 | react-router/docs/how-to/search-params.md | |
| 135 | react-router/docs/explanation/location.md | |
| 136 | ``` | |
| 137 | ||
| 138 | Rules: | |
| 139 | ||
| 140 | - Use `<Link>`/`<NavLink>` for user-initiated internal navigation. | |
| 141 | - Use `redirect` in loaders/actions when navigation follows data loading or mutations. | |
| 142 | - Use `useNavigate` for imperative client-side event navigation. | |
| 143 | - Treat URL params as strings and validate/parse them. | |
| 144 | - Preserve unrelated search params unless intentionally resetting them. | |
| 145 | ||
| 146 | ## SSR in Data Mode | |
| 147 | ||
| 148 | Data Mode SSR is manual and lower-level than Framework Mode. Before implementing or changing SSR, read the Data Mode custom/SSR docs and match existing server abstractions. | |
| 149 | ||
| 150 | Start with: | |
| 151 | ||
| 152 | ```txt | |
| 153 | react-router/docs/start/data/custom.md | |
| 154 | ``` | |
| 155 | ||
| 156 | Look for APIs like `createStaticHandler`, `createStaticRouter`, `StaticRouterProvider`, and hydration data handling in the current app before changing anything. | |
| 157 | ||
| 158 | ## RSC Data | |
| 159 | ||
| 160 | If this Data Mode app uses `unstable_RSCRouteConfig`, RSC route config, or low-level RSC server APIs, also read: | |
| 161 | ||
| 162 | ```txt | |
| 163 | references/rsc.md | |
| 164 | react-router/docs/how-to/react-server-components.md | |
| 165 | ``` |