Dornhoth

import { Injectable, InjectionToken, Inject } from '@angular/core';

export const STORAGE = new InjectionToken<Storage>('Storage', {
  providedIn: 'root',
  factory: () => localStorage
});

@Injectable({
  providedIn: 'root',
})

Dornhoth

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root',
})
export class PersistenceService {

  set(key: string, data: any): void {
    localStorage.setItem(key, JSON.stringify(data));
  }

Dornhoth

{
  "/api": {
    "target": "http://localhost:3000/api",
    "secure": false
  }
}

Dornhoth

import express from 'express';
import cookieParser from 'cookie-parser';
import csurf from 'csurf';

const app = express();
const csrfProtection = csurf({
  cookie: true,
  ignoreMethods: ['GET', 'HEAD', 'OPTIONS'],
});
app.use(cookieParser());

Dornhoth

   "start": "ng serve --proxy-config proxy.conf.json",

Dornhoth

import { Component } from '@angular/core';
import { STORAGE, PersistenceService } from '../services/persistence.service';

@Component({
  selector: 'app-storage',
  templateUrl: './storage.component.html',
  providers: [
    PerstistenceService,
    { provide: STORAGE, useValue: sessionStorage }
  ]

Dornhoth

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})
export class AppComponent {
  title = 'App';
}

Dornhoth

class Greeter implements Person {
    protected person: Person;

    constructor(person: Person) {
        this.person = person;
    }

    public greet(): string {
        return this.person.greet();
    }

Dornhoth

const hiGreeterStudent = new Student();
const helloGreeterStudent = new HelloGreeter(new Student());
const goodMorningGreeterTeacher = new GoodMorningGreeter(new Teacher());

hiGreeterStudent.greet(); //"Hi!"
helloGreeterStudent.greet(); //"Hello!"
goodMorningGreeterTeacher.greet(); //"Good morning!"

Dornhoth

interface Person {
  greet(): string;
}

class Student implements Person {
    public greet(): string {
        return 'Hi!';
    }
}