Discovering Deno: A Fresh Take on Web Development
What is Deno?
Deno is a modern runtime built on the principles of security, simplicity, and performance. Its creator, Ryan Dahl, aimed to address the limitations of Node.js, which he had previously designed. Deno uses the V8 JavaScript engine, just like Node.js, but is written in Rust instead of C++. This gives Deno a significant advantage in terms of security and concurrency.
Comparing Deno and Node.js
When comparing Deno and Node.js, it’s essential to note that both share a common ancestry. However, Deno has some key differences that set it apart. For instance, Deno natively supports TypeScript, eliminating the need for additional transpilation steps. Additionally, Deno modules are designed to be self-contained, reducing the risk of dependency hell.
What is Fresh?
Fresh is a modern web framework designed specifically for Deno. It provides a full-stack solution for building web applications, complete with file system-based routing and a template engine. Fresh uses Preact to render pages on both the server and client, ensuring maximum interactivity and minimal overhead.
Building a Simple Web App with Fresh
To demonstrate the power of Deno and Fresh, let’s build a simple web application. Our app will consist of a REST API, a database, and a frontend. We’ll use the Fresh framework to create a dynamic route, handle requests, and render pages on the server and client.
Understanding the REST API
Our REST API will be built using two files: heroes.ts
and heroes/[id].tsx
. These files will handle GET, POST, PUT, and DELETE requests for our heroes data. We’ll use the deno.postman_collection.json
file to test our API endpoints.
// heroes.ts
import { serve } from 'https://deno.land/[email protected]/http/server.ts';
serve({
'/heroes': () => 'GET /heroes',
'/heroes/:id': ({ params }) => `GET /heroes/${params.id}`,
});
Setting up the Database
For our database, we’ll use a simple array as a global variable. This will allow us to store and retrieve data easily, without the need for a full-fledged database.
let heroes = [
{ id: 1, name: 'Batman' },
{ id: 2, name: 'Superman' },
];
Creating the Frontend
Our frontend will be built using the index.tsx
file, which will combine a title and two components: HeroesScroller
and Create
. We’ll use the twind library for styling and the islands
directory for handling interactivity on the browser.
import { html } from 'https://deno.land/x/[email protected]/html.ts';
import { HeroesScroller } from './HeroesScroller.tsx';
import { Create } from './Create.tsx';
export default () => html`
Heroes App
<${HeroesScroller} />
<${Create} />
`;
Islands of Interactivity
The islands
directory is a special feature of Fresh that allows us to segregate interactivity into specific files. These files will be transpiled to JavaScript on the spot, ensuring seamless execution on the browser.
- HeroesScroller.tsx: Handles the scrolling list of heroes
- Create.tsx: Handles the creation of new heroes
Fresh takes care of rendering these islands on the server and client, providing a seamless user experience.