получение ошибки javascript/typescript «Невозможно прочитать свойство« Элементы неопределенного »

Question

Я получаю сообщение об ошибке« Невозможно прочитать свойство «Элементы неопределенного» в javascript. this ключевое слово всегда undefined в классе Base.

как решить эту проблему? Есть ли проблема с использованием метода static для использования в маршрутизаторе express?

Опция компиляции машинописных имен указывает на ES6.

import * as express from 'express'; 
import {Router, Request, Response, NextFunction, Wrap } from '../../../Core'; 
import {FacadeRequest} from '../../../Common'; 

class Base { 
    public Items: any = { Name: 'Natarajan Ganapathi' }; 
    public Get(): any { 
     return this.Items; 
    } 
} 

class User extends Base { 
    public GetUsers(): any { 
     return super.Get(); 
    } 
} 

export type BoRegistry = { [key: string]:() => any }; 

export class Facade { 
    public static BoRegistry: BoRegistry = {}; 
    public static async GetData(req: Request, res: Response, next: NextFunction): Promise<any> { 
     let promises: Array<any> = []; 
     let reqs = req.body as Array<FacadeRequest>; 
     reqs.forEach(fReq => { 
      let route = Facade.ParseRoute(fReq.Route); 
      let func = Facade.BoRegistry[route.BoName]; 
      if (!func) { 
       throw new Error(route.BoName + ' not register in BoRegistry'); 
      } 
      let bo = func(); 
      promises.push(Facade.Invoke(bo, route, fReq)); 
     }); 
     return await Promise.all(promises); 
    } 

    private static async Invoke(bo: any, route: { BoName: string, MethodName: string }, fReq: FacadeRequest): Promise<any> { 
     let api = bo[route.MethodName]; 
     if (!api) { 
      throw new Error(route.MethodName + ' is not available in ' + route.BoName); 
     } 
     let res = await api(fReq.Request); 
     return { [fReq.Key]: res }; 
    } 

    private static ParseRoute(route: string): { BoName: string, MethodName: string } { 
     let r = route.split('/'); 
     if (r.length < 2 || r.length > 2) { 
      throw new Error('Request contains improper route'); 
     } 
     return { BoName: r[0], MethodName: r[1] }; 
    } 
} 

Facade.BoRegistry['User'] =() => new User(); 

let router: Router = express.Router(); 
router.post('/' + Facade.GetData.name, Wrap(Facade.GetData)); 
export default router; 

{ 
"Message": "Cannot read property 'Items' of undefined", 
"Stack": "TypeError: Cannot read property 'Items' of undefined\n  
at Get (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:17:20)\n  
at GetUsers (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:22:22)\n  
at Function.<anonymous> (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:48:29)\n  
at next (native)\n at __awaiter (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:7:65)\n  
at __awaiter (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:3:12)\n  
at Function.Invoke (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:43:16)\n  
at Base.static.GetData.reqs.forEach.fReq (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:37:38)\n  
at Array.forEach (native)\n  
at /Users/dist/dev/Server/Modules/Base/Router/Facade.js:30:18\n  
at next (native)\n at __awaiter (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:7:65)\n  
at __awaiter (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:3:12)\n  
at GetData (/Users/dist/dev/Server/Modules/Base/Router/Facade.js:27:16)\n  
at exports.Wrap (/Users/dist/dev/Server/Core/Core.js:70:16)\n  
at Layer.handle [as handle_request] (/Users/node_modules/router/lib/layer.js:93:5)" 
} 

Answer 1

"Не удается прочитать свойство 'Предметы' неопределенных",

ошибка Common JavaScript. Вы должны быть осторожными в использовании this или просто использовать функцию стрелки.

Больше

https://basarat.gitbooks.io/typescript/content/docs/arrow-functions.html