Sift

Sift is a routing and utility library for Deno Deploy.

Usage

The documentation below briefly explains the common usage of the functions. You can visit deno doc site to learn more about the API.

Sift imports some functions from preact which causes type conflicts when running using deployctl. You can avoid these conflicts by limiting the types to ns,fetchevent.

deployctl run --libs=ns,fetchevent script.ts

`serve()`

serve() is the routing function. It accepts an object literal with path strings as keys and their corresponding route handlers as values. The path string is processed using path-to-regexp and when the requested path matches the regex, the corresponding handler will be invoked.

import { serve } from "https://deno.land/x/sift@0.3.5/mod.ts";

serve({
  "/": () => new Response("hello world"),
  "/blog/:slug": (request, params) => {
    const post = `Hello, you visited ${params.slug}!`;
    return new Response(post);
  },
  // The route handler of 404 will be invoked when a route handler
  // for the requested path is not found.
  404: () => new Response("not found"),
});

`serveStatic()`

Serve static files hosted on the internet or relative to your source code. It does so by acting as a proxy.

By default, up to 20 static assets that are less than 10MB are cached. You can disable caching by setting cache: false in the options object.

If you’re serving a directory, it is required that the path string end with :filename+ as serveStatic uses this param to construct the absolute URL to the requested resource.

import { serve, serveStatic } from "https://deno.land/x/sift@0.3.5/mod.ts";

serve({
  // You can serve a single file.
  "/": serveStatic("public/index.html", { baseUrl: import.meta.url }),
  // Or a directory of files.
  "/:filename+": serveStatic("public", { baseUrl: import.meta.url }),
  // Serve files hosted on the internet.
  // The URL to the resouce would become https://yourbucket.aws.com/profile.png
  "/profile.png": serveStatic("profile.png", {
    baseUrl: "https://yourbucket.aws.com",
  }),
  // You can modify the fetched response before returning to the request
  // by using the intervene option.
  "/style.css": serveStatic("style.css", {
    baseUrl: import.meta.url,
    // The intervene function is called after the resource is
    // fetched from the source URL. The original request and the
    // fetched response are passed as arguments and a response
    // is expected from the function.
    intervene: (request, response) => {
      // Do some processing to the response.
      return response;
    },
  }),
});

`json()`

Converts an object literal to a JSON string and creates a Response instance with application/json as the content-type.

import { json, serve } from "https://deno.land/x/sift@0.3.5/mod.ts";

serve({
  "/": () => json({ message: "hello world" }),
  "api/create": () => json({ message: "created" }, { status: 201 }),
});

`jsx()`

Renders JSX components to HTML string and creates a Response instance with text/html as the content-type.

When using this function, it is important that your file extension is .jsx or .tsx for Deno Deploy to transform you code and you’ve the h function imported.

import { h, jsx, serve } from "https://deno.land/x/sift@0.3.5/mod.ts";

const App = () => (
  <div>
    <h1>Hello world!</h1>
  </div>
);

const NotFound = () => (
  <div>
    <h1>Page not found</h1>
  </div>
);

serve({
  "/": () => jsx(<App />),
  404: () => jsx(<NotFound />, { status: 404 }),
});