cloudflare-workers

cloudflare-workers

Routing for Cloudflare Workers. Modeled after the ExpressJS framework to easily handle multiple paths in your worker.

Install

$ npm install cloudflare-workers

Usage

const worker = require('cloudflare-workers');

worker.get('/', (request) => new Response('Welcome\n'))
worker.get('/hello', (request) => new Response('Hi there\n'))
worker.get('/goodbye', (request) => new Response('See you later\n'))

addEventListener('fetch', function(event) {
    event.respondWith(worker.handleRequest(event));
});

See 'Using NPM modules' to require the package in your worker.

Supported Operations

worker.use(handler) Add a handler that executes on every path

worker.use(path, handler) Add a handler that executes on a specific path

worker.get(path, handler) Executes a handler on GETs for a specific path

worker.put(path, handler) Executes a handler on PUTs for a specific path

worker.post(path, handler) Executes a handler on POSTs for a specific path

worker.delete(path, handler) Executes a handler on DELETEs for a specific path

worker.head(path, handler) Executes a handler on HEAD for a specific path

Wildcard Paths

Use wildcard * to handle multiple routes with one handler. For example

worker.get('/public/css/*', (request) => fetch(request))

Handler Order

Handlers are executed in the order in which they are registered. If a handler returns undefined the next matching handler will be invoked. Execution of handlers stops once a handler returns a Response object.

Request Context

A request context is created for each request. It can be used to store any data needed during handing of an inbound request. The following handler just saves some header information which can be retrieved later by another handler.

worker.use((request, context) => {
   context.responseHeaders = {
       'Cache-Control': 'private, max-age=0'
   }
})

worker.get('/some/path', (request, context) => {
   return new Response(`response with headers set in context data\n`, {
       headers: context.responseHeaders
   });
})

Path Parameters

Path parameters are supported and can be accessed in the context pathParams value.

worker.get('/user/:name/:account', (request, context) => {
    let username = context.pathParams.name;
    let accountId = context.pathParams.account;
    return new Response(`Hello ${username}. Your account number is ${accountId}\n`)
})

Context waitUntil()

If background processing needs to be performed use context.waitUntil to wait for a background task to complete. Calling waitUntil will invoke event.waitUntil on the original fetch event.

Special Handlers

Special handlers can be setup for additional control of the request/response flow. If the special handler returns a Response object normal route processing will stop and the response will be sent out.

The ingressHandler executes prior to any route handlers.

worker.ingressHandler = (request, context) => { context.startTime = new Date(); }

The egressHandler executes right before sending a response from a route handler.

worker.egressHandler = (request, context, response) => {
    let endTime = new Date();
    let duration = endTime.valueOf() - context.startTime.valueOf();
    // do something with duration data
}

The notFoundHandler executes if the incoming request does not match any routes.

worker.notFoundHandler = (request, context) => {
    return new Response('page not found!', { status: 404 });
}

The errorHandler executes if any error is thrown during processing of the request.

worker.errorHandler = (request, context, err) => {
    return new Response(`internal error: ${err}`, { status: 500 })
}

License

MIT license; see LICENSE.