Lunch N Learn Typescript Basics

LunchNLearn-TypescripBasics.js

enum OrderType {
	stationery,
	food,
	electronics
}

enum Priority {
	low,
	medium,
	high
}

interface Item {
	id : number,
	description : string
}

interface Order {
	id : number,
	type : OrderType,
	priority : Priority,
	items : Item[]
}

interface Repository<T,U> {
    Add(entity : U) : number;
	Get(id : T) : U;
	GetAll() : U[];
	Put(id : T, entity : U) : void;
}

class StationeryOrder implements Order {
	
	static instanceCount : number = 0;
	
	id : number; 
	type : OrderType = OrderType.stationery;
	priority : Priority;
	items : Item[] = [
		{ id: 1, description : "Staple"},
		{ id: 2, description : "Pencil"},
		{ id: 3, description : "Notepad"}
	];
	
	constructor(priority : Priority) {
		StationeryOrder.instanceCount += 1;
		this.id = StationeryOrder.instanceCount;
	}
}

class FoodOrder implements Order {
	
	static instanceCount : number = 0;
	id : number; 
	type : OrderType = OrderType.food;
	priority : Priority;
	
	items : Item[] = [
		{ id: 1, description : "Sandwich"},
		{ id: 2, description : "Fries"},
		{ id: 3, description : "Soda"}
	]; 
	
	constructor(priority : Priority) {
		FoodOrder.instanceCount += 1;
		this.id = FoodOrder.instanceCount;
		this.priority = priority;
	}
	
}

class ElectronicsOrder implements Order {

	static instanceCount : number = 0;
	id : number; 
	type : OrderType = OrderType.electronics;
	priority : Priority;
	
	items : Item[] = [
		{ id: 1, description : "Keyboard"},
		{ id: 2, description : "USB drive"},
		{ id: 3, description : "Headset"}
	]; 
	
	constructor();
	constructor(priority? : Priority) {
		ElectronicsOrder.instanceCount += 1;
		this.id = ElectronicsOrder.instanceCount;
		this.priority = priority || Priority.medium ;
	}
	
}


class NumberBaseRepository<U> implements Repository<number, U> {
	
	protected items : U[];
	
	Add(item : U) {
		this.items.push(item);
		return this.items.length - 1;
	};
	
	Get(id : number) {
		return this.items[id];
	}
	
	GetAll() {
		return this.items;
	}
	
	Put(id : number, item : U) {
		this.items[id] = item;
	}
}


class DevRepository extends NumberBaseRepository<string> {
	
	constructor() {
		this.items = ["Supriya", "Juan", "Andy", "Matthews"];
		super();
	}
};

class OrderRepository extends NumberBaseRepository<Order> {
	constructor() {
		this.items = [];
		super();
	}
}

var devRepositoryInstance = new DevRepository();
devRepositoryInstance.Add("Joanne");
devRepositoryInstance.Put(1, "Juan, the Awesome One!")

var orderRepositoryInstance = new OrderRepository();
orderRepositoryInstance.Add(new StationeryOrder(Priority.low));
orderRepositoryInstance.Add(new StationeryOrder(Priority.high));
orderRepositoryInstance.Add(new FoodOrder(Priority.medium));
orderRepositoryInstance.Add(new ElectronicsOrder());

var orderOutput = JSON.stringify(orderRepositoryInstance, null, '     ');

var devUIList = document.createElement("UL");
for (var dev of devRepositoryInstance.GetAll()) {
    var devUIItem = document.createElement("LI");
	var devTextNode = document.createTextNode(dev);
	devUIItem.appendChild(devTextNode);
	devUIList.appendChild(devUIItem);
}

document.body.appendChild(devUIList);

var orderDump = document.createElement("DIV");
orderDump.innerText = orderOutput;
document.body.appendChild(orderDump);