deligenius

Lightweight Deno middleware framework

Features

Light weight (11kb)
Near deno http module performance
Body parser middleware option
Gentle error handling

Quick Start

Hello World example

Use your favourite editor, copy below to app.ts

// ./app.ts
import { Application } from "https://raw.githubusercontent.com/deligenius/dg.ts/master/mod.ts";

let app = new Application({ port: 8000 }).listen();

app.use((ctx) => {
  ctx.send("Hello World!");
});

Run program with

> deno run --allow-net ./app.ts

Router

If you write code in the express.js way, it’s recommended to use Router, as it comes with restful methods: get, post, put, delete …

import {
  Application,
  Router,
} from "https://raw.githubusercontent.com/deligenius/dg.ts/master/mod.ts";

let app = new Application({ port: 8000 }).listen();
let router = new Router("/");

app.use(router);

router.get("/", ({ req, res }, next) => {
  res.send("You reached " + req.url);
});

🔝

Use BodyParser

dg.ts has a separate middleware module: bodyParser, which can be used to parse parameter, query, json etc,. We will use mid from bodyParser which includes many pre-configured middlewares for dg.ts

Get `query` parameter

import {
  Application,
  Router,
} from "https://raw.githubusercontent.com/deligenius/dg.ts/master/mod.ts";
import { mid } from "https://raw.githubusercontent.com/deligenius/bodyparser/master/mod.ts";

let app = new Application({ port: 8000 }).listen();

app.use(mid.query(), (ctx) => {
  let query = ctx.req.query;
  ctx.send(query);
});

Get `json` data

app.use(mid.json(), (ctx) => {
  let json = ctx.req.json;
  ctx.send(json);
});

Get `params`

app.use(mid.params("/:name/:age"), (ctx) => {
  let params = ctx.req.params;
  ctx.send(params);
});

Get `multipart/form-data`

consider use dg.ts official Multiparser

Get `urlencoded` form data

app.use(mid.urlencoded(), (ctx) => {
  let urlencoded = ctx.req.urlencoded;
  ctx.send(urlencoded);
});

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Error handling

dg.ts has a default error handler handleError in every Application and Router

Error handling In middleware

app.use(async (ctx, next) => {
  try {
    methodThrowError()
  } catch (e) {
    console.log(e);
  }
});

Throw HttpError

All the throw new HttpError(message, statusCode) will be handled by the app.handleError or router.handleError

app.use(async (ctx, next) => {
  throw new HttpError("no user found", 404)
});

Override `errorHandler`

app.errorHandler and router.errorHandler can be override

app.handleError = (err, ctx) => {
  if (err instanceof HttpError) {
    ctx.status(err.status).send("http error");
  } else {
    ctx.send("some other error");
  }
};

🔝

Contributors

@gjuoun