# Introduction
@t2ee/vader is a routing component (with JAX-RS like grammars). It is to be used with [koa@2](https://github.com/koajs/koa).
# Installation
`npm i reflect-metadata @t2ee/core @t2ee/sl4js koa@2 @t2ee/vader -S`
# Usage
## Basic Usage
```typescript
import 'reflect-metadata';
import * as Koa from 'koa';
import {
Path,
Router,
QueryParam,
Response,
GET,
} from '@t2ee/vader';
const router = Router.newInstance();
@Path('')
class Controller {
@GET
@Path('/say')
say(@QueryParam('message') message: string) {
const response = new Response();
response.body = message;
return response;
}
}
router.use(Controller);
const app = new Koa();
app.use(router.routes());
app.listen(8080);
```
## Receive POST Data
```typescript
@Path('/')
class Controller {
@POST
@Consumes('application/json')
@Path('/login')
say(@Body body) {
const response = new Response();
response.body = body;
return response;
}
}
```
## Use Middlewares
Middlewares can be either injected on classes or methods.
### Direct Register Middlewares
```typescript
async function handler(request: Request): Promise {
if (request.headers.get('SECRET-KEY') !== 'secret') {
throw new Error('WRONG!!!!!!');
}
return request;
}
@Before(handler)
class Controller {
}
```
### Through Class Methods
```typescript
async function handler(request: Request): Promise {
if (request.headers.get('SECRET-KEY') !== 'secret') {
throw new Error('WRONG!!!!!!');
}
return request;
}
@Before('checkSecret')
class Controller {
async checkSecret(@Context request: Request): Promise {
if (request.headers.get('SECRET-KEY') !== 'secret') {
throw new Error('WRONG!!!!!!');
}
return request;
}
}
```
### Register For All Routes
```typescript
router.userMiddlewares(before, afters, afterAlls);
```
### Custom Context Variables
### Binding directly
Let's say we wanted to bind headers `SECRET-KEY` to a variable.
```typescript
function Secret(target: Object, key: string) {
return Contexted((req: Request) => req.headers.get('SECRET-KEY'));
}
class Controller {
@Secret secret: string;
}
```
### Binding by class
```typescript
class User {
username: string;
password: string;
}
router.provideContext(User, (req: Request) => {
const user = new User();
// fill up user
return user;
});
class Controller {
@Context user: User;
}
```
## Handlers
Exceptions and extra configurations are implemented by `Auto Configuration`. To provide a custom handler, see example below.
```typescript
@Configuration
class Config {
@Bean('NotFoundHandler)
notFoundHandler(): NotFoundHandler {
return {
async handle(req: Request, data: void): Promise {
// handle unmatched routes here.
}
}
}
@Bean('ErrorHandler')
errorHandler(): ErrorHandler {
return {
async handle(req: Request, error: Error): Promise {
// handle uncaught errors here.
}
}
}
}
```
# API
## Coming soon ...
Coming soon...
