Rokot-apicontroller NPM

rokot-apicontroller

Rokot - Rocketmakers TypeScript NodeJs Platform

Introduction

A typescript decorators based solution to declaratively define routes for REST based api This library creates metadata about the defined routes to allow auto route generation

Getting Started

Installation

Install via npm

npm i rokot-apicontroller

Example

If you want to specify any additional custom Middleware, you can define them as below and annotate with the middleware decorator

import { api } from "rokot-apicontroller";

class Middleware {
  @api.middlewareFunction("one")
  static one = (req: Express.Request, res: Express.Response, next: () => void) => {
    console.log("one")
    next();
  }
  @api.middlewareFunction("two")
  static two(req: Express.Request, res: Express.Response, next: () => void) {
    console.log("two")
    next();
  }
  @api.middlewareFunction("three")
  three(req: Express.Request, res: Express.Response, next: () => void) {
    console.log("three")
    next();
  }

  @api.middlewareProviderFunction("logger", 1)
  static logger(log: string) {
    return (req: Express.Request, res: Express.Response, next: () => void) => {
      console.log(log, req)
      next();
    }
  }

  @api.middlewareProviderFunction("simplelogger", 0, 1)
  static simplelogger(log?: string) {
    return (req: Express.Request, res: Express.Response, next: () => void) => {
      console.log(log || "Unknown", req)
      next();
    }
  }
}

You can optionally register the middleware directly via the registerMiddlewareFunction method

import { registerMiddlewareFunction } from "rokot-apicontroller";

registerMiddlewareFunction("four", (req: Express.Request, res: Express.Response, next: () => void) => {
  console.log("four")
  next();
})

You can optionally create your own request to shape the request handler object:

import { IExpressApiRequest, ExpressRouteBuilder, ExpressApiRequest, IExpressRequest } from "rokot-apicontroller";

export interface IUser {
  id: string;
  userName: string
}

export interface IRequest<TBody, TResponse, TParams, TQuery> extends IExpressApiRequest<TBody, TResponse, TParams, TQuery> {
  isAuthenticated(): boolean
  isUnauthenticated(): boolean
  user: IUser
}

export interface IGetRequest<TResponse, TParams, TQuery> extends IRequest<void, TResponse, TParams, TQuery> {
}

export class CustomExpressApiRequest<TBody, TResponse, TParams, TQuery>
  extends ExpressApiRequest<TBody, TResponse, TParams, TQuery>
  implements IRequest<TBody, TResponse, TParams, TQuery> {
  user: IUser
  constructor(native: IExpressRequest) {
    super(native)
    this.user = native.request["user"];
  }
  isAuthenticated(): boolean {
    return this.native.request["isAuthenticated"]()
  }
  isUnauthenticated(): boolean {
    return this.native.request["isUnauthenticated"]()
  }
}

export class CustomExpressRouteBuilder extends ExpressRouteBuilder {
  protected createHandler(req: IExpressRequest) {
    return new CustomExpressApiRequest<any, any, any, any>(req)
  }
}

You can then specify controllers and their routes:

import { api } from "rokot-apicontroller";
import { IRequest, IGetRequest, IUser } from "./customRequest"; // from file above


interface IGroup {
  id: string;
  name: string;
  members: IUser[];
}

/*
Register the MiddlewareController
: all route paths are prefixed with "/middleware"
: all routes use the middleware function "one"
  then the resolved middleware via provider "logger"
  (using "MiddlewareController" as the required param)
*/
@api.controller("MiddlewareController", "/middleware", b => b.add("one").add("logger", "MiddlewareController"))
class MiddlewareController {

  @api.route(":id")
  @api.verbs("get", "options")
  @api.middleware("two")
  @api.middleware("three")
  get(req: IGetRequest<IGroup, { id: string }, void>) {
    req.sendOk({ id: req.params.id, name: "group", members: [{ id: "1", userName: "User 1" }] });
  }

  @api.route()
  @api.verbs("get", "options")
  getAll(req: IGetRequest<IGroup[], void, void>) {
    req.sendOk([
      { id: "1", name: "group", members: [{ id: "1", userName: "User 1" }] }
    ]);
  }

  @api.route()
  @api.contentType("application/x-www-form-urlencoded")
  post(req: IRequest<IGroup, IGroup, void, void>) {
    req.sendCreated(req.body);
  }

  @api.route(":id")
  delete(req: IGetRequest<void, { id: string }, void>) {
    var id = req.params.id;
    req.sendNoContent()
  }
}

To build your routes (and bootstrap your api) you can

import { CustomExpressRouteBuilder } from "./customRequest"; // from file above
import { ApiBuilder, apiControllers, middlewareFunctions } from "rokot-apicontroller";
import { ConsoleLogger } from "rokot-log";
import * as express from 'express';

export function boot(port: number) {
  const app = express();
  const logger = ConsoleLogger.create("Api Routes", { level: "trace" });

  const apiBuilder = new ApiBuilder(logger)
  const runtimeApi = apiBuilder.buildRuntime(apiControllers, middlewareFunctions)
  if (runtimeApi.errors && runtimeApi.errors.length) {
    console.log("Unable to build api model - Service stopping!")
    return;
  }

  const builder = new CustomExpressRouteBuilder(logger, app);
  const ok = builder.build(runtimeApi);
  if (!ok) {
    console.log("Unable to build express routes - Service stopping!")
    return;
  }

  app.listen(port, () => {
    console.log(`Server listening on port ${port}!`);
  });
}

Validation

rokot-apicontroller is agnostic of which validation framework you want to use. You can specify a validation spec for the body, queryString or route params (typed as any) using:

@api.bodyValidationSpec({/* your body spec */})
@api.paramsValidationSpec({/* your route params spec */})
@api.queryValidationSpec({/* your query spec */})

Here is an example using the rokot-validate package

import { api } from "rokot-apicontroller";
import { IRequest, IUser } from "./customRequest"; // from file above
import { createClientConstraintSpec } from "rokot-validate";

interface IRequireValidation {
  id: string;
  name: string;
  members: IUser[];
}

const bodySpec = createClientConstraintSpec<IRequireValidation>(b => {
  return {
    id: { absence: true },
    name: b.stringMandatory(),
    members: b.arrayValidator<IUser>({ id: b.stringMandatory(), userName: b.stringMandatory() })
  }
})

@api.controller("ValidatedController", "/validated")
class ValidatedController {

  @api.route()
  @api.bodyValidationSpec(bodySpec)
  post(req: IRequest<IRequireValidation, IRequireValidation, void, void>) {
    req.sendCreated(req.body);
  }
}

You then need to modify your bootstrap to add a validation function (that will validate the payload via its spec and return a validated copy of the payload) to the RouteBuilder constructor

import { CustomExpressRouteBuilder } from "./customRequest"; // from file above
import { ApiBuilder, apiControllers, middlewareFunctions } from "rokot-apicontroller";
import { ConsoleLogger } from "rokot-log";
import * as express from 'express';
import { Validation, ClientConstraintSpec } from "rokot-validate";

/* part will be "body" | "params" | "query" */
function validate<T>(spec: ClientConstraintSpec<T>, item: any, part: string) {
  return Validation.executeClient<T>(item, spec)
}

export function boot(port: number) {
  const app = express();
  const logger = ConsoleLogger.create("Api Routes", { level: "trace" });

  const apiBuilder = new ApiBuilder(logger)
  const runtimeApi = apiBuilder.buildRuntime(apiControllers, middlewareFunctions)
  if (runtimeApi.errors && runtimeApi.errors.length) {
    console.log("Unable to build api model - Service stopping!")
    return;
  }

  const builder = new CustomExpressRouteBuilder(logger, app, undefined, validate);
  const ok = builder.build(runtimeApi);
  if (!ok) {
    console.log("Unable to build express routes - Service stopping!")
    return;
  }

  app.listen(port, () => {
    console.log(`Server listening on port ${port}!`);
  });
}

If you want to expose these validation spec's to your client, you can add a controller like this!

import { api, validationSpecDictionary, IStringDictionary, IRouteValidationSpec } from "rokot-apicontroller";
import { IGetRequest } from "./customRequest"; // from file above

@api.controller("ValidationSpecController", "validationSpec")
class ValidationSpecController {
  @api.route()
  get(req: IGetRequest<IStringDictionary<IRouteValidationSpec>, void, void>) {
    req.send(200, validationSpecDictionary)
  }
}

Notes

The route methods should be instance members, and have a single param req of type IApiRequest<TBody,TResponse,TParams,TQuery,TNative> It strongly types all aspects of the request to make consuming them simpler within the route

There is a corresponding IExpressApiRequest<TBody, TResponse, TParams, TQuery> that supplies the TNative with { request: express.Request, response: express.Response, next: express.NextFunction }

The @api.controller decorator allows you to specify a controller name, route path prefix, and optionally the middleware keys to apply to all the controller contained routes.

NOTE: Its strongly recommended to supply the name of the class as the first parameter of @api.controller

The @api.route decorator must be supplied on all controller routes, it specifies the route path of the operation.

The optional @api.middleware("three") decorator on the route method allows you to specify addition middleware to implement within the route (you can apply this decorator multiple times per route to add additional middleware's).

The controllers middleware will run (in specified order) before the routes middleware is run (also in specified order)

The route verb (get,put,post,delete etc) is determined by the following rules:

If the route method is named exactly as a verb - that verb is used.
If you specify the optional @api.verbs(...) decorator - that verb (or those verbs) will be used.
if all else fails, get.

The route path is determined by combining the (optional) routePrefix from @api.controller with the @api.route decorator values

The optional @api.contentType decorator can be applied once on any controller routes, it specifies the content type of the request body (the default is "application/json").