katrine

Typescript based node.js framework

For development lightweight server apps.

Table of Contents

• Related links
• Documentation
  • Installation
  • Bootstrap Katrine
  • Controllers and actions
  • View
  • Login or logout user
  • Access control

Related links

• Boilerplate project https://github.com/AsterAInpm/katrine-hello-world/
• Github project https://github.com/AsterAInpm/katrine
• npmjs.org https://www.npmjs.com/package/katrine

Documentation

Installation

Add following dependencies, in your project

  "dependencies": {
    "@types/node": "9.6.7",
    "katrine": "^1.4.2",
    "typescript": "^3.3.3"
  }

Bootstrap Katrine

To start app you need just 2 necessary actions:

• Load atleast one valid Katrine controller with valid action
• Run the app

import { KatrineApp } from 'katrine';

/**
 * Katrine requires directories by absolute path or relative path
 * if dir path start with '.' (dot) Katrine will require relatively
 * Else Katrine will require dirs by absolute path
 *
 * Any controllers must be annotated by @controller decorator
 */
KatrineApp.loadControllers([
  './controller/IndexController',
  './controller/UserController',
  './controller/AdminController',
]);

// public folder optionally 
KatrineApp.setPublicFolder('public'); // express.js compatible public folder

// run with default settings
KatrineApp.run({});

Controllers and actions

To define controller use a @controller decorator. Framework will require the file. When you call typescript KatrineApp.loadControllers and if class has @controller decorator Katrine will recognize class as actions holder.

KatrineController is userfull class that contains few methods of rendering. And you will be able to render content by different methods. KatrineController is unnecessary, but strongly recommended for using. Also without KatrineController you could't use internal pug rendering system (View component)

import { KatrineController, controller } from 'katrine';

@controller
export default class IndexController extends KatrineController {
  
}

Actions

@action annotation receives 2 params

• route: string, express.js compatible route
• requestType: HTTPRequestType, POST or GET type

Actions can return Promise or string as result.

import { KatrineController, controller, action, HTTPRequestType } from 'katrine';

@controller
export default class SomeController extends KatrineController {
      
    @action('/api/v1/*/delete', HTTPRequestType.POST)
    delete(req): string {
      const id = req.body.id;
      return JSON.stringify({
        status: 'success',
        data: id
      });    
    }
    
    // example of async action
    @action('/user/random')
    async getRandomUserAction(req): Promise<any> {
      const userData = await User.findRandomUser();
      return JSON.stringify({
        status: 'success',
        userId: userData.id
      });
    }
}

View

Framework uses pug as template engine. All render methods gathered in KatrineController

    // Pug file. Which you prefer to use when method render is called 
    protected getLayout(): string;
    
    // renders pug file with layout `getLayout()` 
    protected render(viewPath: any, params?: {}): any;
    
    // renders plain string. Method usefull when you don't need to use separete pug template for action 
    protected renderString(content: string, params?: {}): any;
    
    // renders particular pug template in particular layout
    protected renderLyout(viewPath: string, layoutPath: string, params: any): any;

Example of real controller.

import { action, KatrineController, controller } from 'katrine';

@controller
export default class IndexController extends KatrineController {

  /**
   *  Method used by KatrineController to define layout for any render* methods. 
   */
  getLayout() : string {
    return './view/layout/main.pug';
  }

  @action('/') // express compatible route
  homePageIndexAction(req): string {
    return this.render('./view/actions/index.pug', {});
  }


  @action('404') // Will call this action when route doesn't match on any valid actions
  pageNotFound(req): string {
    return this.render('./view/system/404.pug',{});
  }

  @action('403') // Will call this action when RBAC system rejects request by access rules. 
  accessDenied(req): string {
    return this.render('./view/system/403.pug',{});
  }
}

Login or logout user

There are 2 methods to login and logout user.

  KatrineApp.auth(requestSession);
  KatrineApp.authLogoutUser(requestSession);

Full example of posible UserController within your app.

@controller
export default class UserController extends KatrineController {
  private createUser(userData) : UserInterface {
    const user = new UserObject(userData.id, userData.role, userData);
    user.setSigned();

    return user;
  }
  
  @accessByAuth(AuthStatus.NOT_LOGGED_IN)
  @action('/user/login', HTTPRequestType.POST)
  async loginUserAction(req) {
    const email = req.body.email;
    const password = req.body.password;

    try {
      const userData = await User.findByEmailAndPassword(email, password);

      if (userData) {
        const userObject = this.createUser(userData);
        KatrineApp.auth(req.session, userObject);
      } else {
        throw 'User Email or password incorrect';
      }

      return JSON.stringify({
        status: 'success',
        messsage: '',
        data: {
          role: userData.role,
          id: userData.id
        }
      });
    } catch (e) {

      console.error(e);

      return JSON.stringify({
        status: 'error',
        message: typeof e === 'string' ? e : 'User Email or password incorrect'
      })
    }

  }

  @accessByAuth(AuthStatus.LOGGED_IN)
  @action('/user/logout')
  logOutAction(req): string {
    KatrineApp.authLogoutUser(req.session);
    
    return JSON.stringify({
      status : 'success'
    });
  }
}

Access control

To restrict access to actions there are two decorators. Decorators works by OR logic e.g: if (!rule_1 || !rule_n) reject ..., so you can combine them to make more complex logic of access control flow

    // allows user to call action if his role equals `roles` param
    @accessByRole(roles: string | string[]) 
    
    // allows user to call action according to his Auth state `signed in / not signed in`
    @accessByAuth(auth: AuthStatus)

Fill free to make issue reports, or request a features

My email [e-mail]

Alex.