Handler Function

In this section we cover everything you need to know about a handler function. As in any other http library each route is assigned a handle function and it handles the incoming request to the specific route and returns response. In cloud-rover a handler function must a carry a specific signature.

Signature

handler(rc: RC): Promise<Response>;

It passes an RC object which stands for Router Context.

RC Interface

interface RC {
  request: Request;
  params: RouteParams;
  env: unknown;
  ctx: ExecutionContext;
}

Here each parameter contains information regarding the request, context or environment. A brief introduction of each parameter is given below:

• request: This is the standard Request interface for fetch request. It contains all the necessary information regarding the request.
• params: RouteParams is an interface provided with cloud-rover, it has two properties pathParams and queryParams please refer to Dynamic Routing section to learn more.
• env: This is cloudflare's binding of worker platform. This is provided by cloudflare. Bindings allow your Worker to interact with resources on the Cloudflare Developer Platform. Learn more here
• ctx: provides run-time APIs. This also comes with core worker package from cloudflare. Learn more.

Example handler

export async function handleRoot(rc): Promise<Response> {
	return reply.text('Hello World');
}

Reading JSON Request Body

You can read request body using request.json(). Here's an example

export async function handlePost(rc): Promise<Response> {
	const body = await rc.request.json();
	const name = body.name;
	return reply.text(`"Hello Mr. ${name}`);
}

In typescript use RC as parameter type

export async function handlePost(rc: RC): Promise<Response> {
	const body = await rc.request.json();
	const name = body.name;
	return reply.text(`"Hello Mr. ${name}`);
}

tip

Instead of typing rc.request.foo all the time it's recommended to destructure the object and use them directly.

Destructuring RC

We can write the previous example like this

    export async function handlePost({request}): Promise<Response> {
	const body = await request.json();
	const name = body.name;
	return reply.text(`"Hello Mr. ${name}`);
}

or in typescript like this

export async function handlePost({request}: RC): Promise<Response> {
	const body = await request.json();
	const name = body.name;
	return reply.text(`"Hello Mr. ${name}`);
}

To learn more about the request object please refer to the [https://developer.mozilla.org/en-US/docs/Web/API/Request](MDN Reference).