Dango | Functional routing controllers for express

Dango

Dumpling in japaneese.

POC for functional controllers and route-handlers in express.

What is expected

• Functional way of writing routers
• Follow function programming concepts
• Composition over inheritance

  Update v1.0.0

  I'm not very familiar with functional programming and it's concepts. I'm learning it now and it turns out the v0.0.2 dango code was not functional at all and it has been scraped see tag v0.0.2. I'll be proposing a new API for dango again. As we have been doing OOP for so long, FP will take some time to be fully understood.

Breaking changes

v2.0.0

• The router handler ctx is now an object

  // B= body, P= params, Q=query
  // types createRoute<B,P,Q>
  ctx = { req, res, body, params, query }
  

• see createRoute for usage

v1.0.0

• CreateHandler has been scraped
• CreateController params changed.

  Proposed API

Core:

• createExpressServer
• createController
• createRoute

Express wrapper

• A wrapper on express to inject controllers.
• Can be used as

import express from 'express';
import { createExpressServer } from 'dango-core';

const app = express();

createExpressServer(app, { controllers: ['./controllers/*.ts'] }).listen(3000, () => {
  console.log('http://localhost:3000');
});

• controller definition should be a glob path.

Controllers

• A controller can be created with createController method.

import { createController } from 'dango-core';

export default createController(
  '/',
  [
    {
      path: '/',
      method: 'get',
      handler: ({req, res, params, query}) => {
        res.send('is this working ?');
      },
      middlewares: [
        (req, res, next) => {
          res.send("I'm local");
        },
      ],
    },
  ],
  [
    (req, res, next) => {
      res.send("I'm global");
    },
  ],
);

• Should be default exported from the controller file.

Routes

This is a low level API which can be used to create routes with proper type definitions for request body,params and query. Can be used with createController for modularity.

• BREAKING CHANGE

  • v2.0.0 the handler ctx is now an object

• standalone ```ts import { createRoute } from 'dango-core';

  const userRoute = createRoute<{ user: string }>({ path: '/user', method: 'options', handler: ({req, res, body}) => { // proper ts definitions req.body.user; }, });

- with controller
```ts
  import { createController } from 'dango-core';

  export default createController('/aa', [userRoute]);

• With express router style function chaining ```ts import { createRoute } from 'dango-core';

const home = createRoute<{ user: string }>('/') .method('get') .handler(({ res }) => res.send('OK'));

#### Middlewares

##### Global

```ts
import express from 'express';
import { createExpressServer } from 'dango-core';
const app = express();

createExpressServer(app, {
  controllers: ['controllers/**.ts'],
  middlewares: [
    (req, res, next) => {
      res.send("I'm global");
    },
  ],
}).listen(4000, () => console.log('http://localhost:4000'));

Controller specific

import { createController } from 'dango-core';

export default createController(
  '/test',
  [
    {
      path: '/yolo',
      method: 'get',
      handler: ({req, res}) => {
        res.send('is this working ?');
      },
    },
  ],
  [
    (req, res, next) => {
      res.send("I'm controller specific");
    },
  ],
);

Route specific

import { createController } from 'dango-core';

export default createController('/test', [
  {
    path: '/yolo',
    method: 'get',
    handler: ({req, res}) => {
      res.send('is this working ?');
    },
    middlewares: [
      (req, res, next) => {
        res.send("I'm route specific");
      },
    ],
  },
]);

Helpers

• response.sendError

  • send HTTP errors from response with proper intellisense

    import { createController, createRoute } from 'dango-core';
    
    const someRoute = createRoute<{ user: string }>({
      path: '/',
      method: 'get',
      handler: ({req, res, body}) => {
        res.sendError(401,"Nope")
      },
    });
    
    export default createController('/home', [someRoute]);
    

Packages

Package	version
Core
Example	NA