By default, Remix will handle generating the HTTP Response for you. If you want to customize this behavior, you can run npx remix reveal to generate an app/entry.server.tsx (or .jsx) that will take precedence. The default export of this module is a function that lets you create the response, including HTTP status, headers, and HTML, giving you full control over the way the markup is generated and sent to the client.
This module should render the markup for the current page using a <RemixServer> element with the context and url for the current request. This markup will (optionally) be re-hydrated once JavaScript loads in the browser using the browser entry module.
handleDataRequestYou can export an optional handleDataRequest function that will allow you to modify the response of a data request. These are the requests that do not render HTML, but rather return the loader and action data to the browser once client-side hydration has occurred.
export function handleDataRequest(
response: Response,
{
request,
params,
context,
}: LoaderFunctionArgs | ActionFunctionArgs
) {
response.headers.set("X-Custom-Header", "value");
return response;
}
handleErrorBy default, Remix will log encountered server-side errors to the console. If you'd like more control over the logging, or would like to also report these errors to an external service, then you can export an optional handleError function which will give you control (and will disable the built-in error logging).
export function handleError(
error: unknown,
{
request,
params,
context,
}: LoaderFunctionArgs | ActionFunctionArgs
) {
if (!request.signal.aborted) {
sendErrorToErrorReportingService(error);
console.error(formatErrorForJsonLogging(error));
}
}
Note that you generally want to avoid logging when the request was aborted, since Remix's cancellation and race-condition handling can cause a lot of requests to be aborted.
When you are streaming your HTML responses via renderToPipeableStream or renderToReadableStream, your own handleError implementation will only handle errors encountered during the initial shell render. If you encounter a rendering error during subsequent streamed rendering you will need handle these errors manually since the Remix server has already sent the Response by that point.
renderToPipeableStream, you can handle these errors in the onError callback function. You will need to toggle a boolean when the in onShellReady so you know if the error was a shell rendering error (and can be ignored) or an async rendering error (and must be handled).
entry.server.tsx for Node.renderToReadableStream, you can handle these errors in the onError callback function
entry.server.tsx for CloudflareNote that this does not handle thrown Response instances from your loader/action functions. The intention of this handler is to find bugs in your code which result in unexpected thrown errors. If you are detecting a scenario and throwing a 401/404/etc. Response in your loader/action then it's an expected flow that is handled by your code. If you also wish to log, or send those to an external service, that should be done at the time you throw the response.
