Introduction

Polku originates from Finnish, meaning path or route, and is a NodeJS library which focuses on defining APIs using typescript decorators.

Installing

npm install polku

Bootstrapping

Create file in the root of your project

import {DefaultExpressApplication} from "polku/express";
import {Server} from "http";
import {AddressInfo} from "net";

const componentScanPaths = [__dirname];

new DefaultExpressApplication(componentScanPaths).start(3000).then((server: Server) => {
    console.log(`Server listening at port ${(server.address() as AddressInfo).port}`);

    setTimeout(() => {
        server.close();
    }, 5000)
});

Specifying controllers

Place a file somewhere in your project with following contents:

import {Controller, Route, RouteContext} from "polku";

@Controller({
    prefix: "/"
})
export class TestController {
    constructor() {
    }

    @Route({ "method": "get", "path": "/hello/:name" })
    private hello (ctx: RouteContext) {
        return `Hello, ${ctx.request.params['name']}`
    }
}

Restart your node application and you should see the response at http:[your_host]:3000/hello/cnorris.

Injecting services

Define a service somewhere in your project

import {Service} from "polku";

@Service({
    name: "TestService"
})
export class TestService {
    sayHello(name: string): string {
        return `Hello, ${name}`
    }
}

And inject it to your controller

import {Controller, Route, RouteContext, Inject} from "polku";
import {TestService} from "./test-service";

@Controller({
    prefix: "/"
})
export class TestController {
    constructor(@Inject("TestService") private _testService: TestService) {
    }

    @Route({ "method": "get", "path": "/hello/:name" })
    private hello (ctx: RouteContext) {
        return {message: this._testService.sayHello(ctx.request.params['name'])};
    }
}

Chaining services

Services can inject another services. Define another service somewhere in your project

import {Service} from "polku";

@Service({
    name: "SubService"
})
export class SubService {
    test(): string {
        return "foo";
    }
}

The go and modify the TestService from previous example:

import {Service, Inject} from "polku";
import {SubService} from "./sub-service";

@Service({
    name: "TestService"
})
export class TestService {
    constructor(@Inject("SubService") private _subService: SubService) {
    }

    sayHello(name): string {
        return `Hello, ${name}! And the sub-service says: ${this._subService.test()}`;
    }
}