tko - awesomeness using typescript with knockout.js
DESCRIPTION
Presentation for the session held on CodeCamp Macedonia 2013. Last year we saw what TypeScript promises. Now a year later, it's time to see whether it delivers. In my opinion, it does, and when used with knockout.js it does so with a punch. The TypeScript generics mesh beautifully with knockout's observables and result in a dynamic, declarative, and type-safe code base, that's easy to work with. The presentation also covers a note of the future of the C# language, based on information for proposed language features. The code shown can be seen on https://github.com/sweko/tko The presentation is live on http://monaco-swekster.azurewebsites.net/Roles.tko.htmlTRANSCRIPT
TKO Knocking it out of the ball park with
TypeScript and knockout.js
Wekoslav StefanovskiSenior Developer, Seavus
Agenda
A little bit of historyA little bit of presentWhy is TypeScript needed? How is it used?Why is knockout needed? How is it used?Why are they great together?Bonus Topic: Surprise
A little bit of history
What is this thing called Javascript???
Prototype-based dynamic scripting language
Build in Netscape in 1995, initially focused on
non-professional developers.
Standardized as ECMAScript (in 1999)
Still the version most browsers / developers use.
A little bit of history, part II
What is this thing called DOM???
Even worse consistency than javascript.
Latest specification is from 2004, a.k.a. Internet Prehistory
jQuery (and friends) to the rescue
Still, it’s not a traditional programming object model
– Hard to manipulate
– Hard to automate
A little bit of present
The rise of the Single-Page Application
Heavy client logic, getting heavier
Stateless web is dead and more alive than ever
The attack of the APIs and services
Ongoing M/V separation
Why is TypeScript needed
Javascript’s got 99 problems but types ain’t one
– Variable hoisting – no implicit global variables in typescript
– Truthy and falsy values – only booleans allowed in boolean
checks
– No explicit includes – has explicit references and dependencies
– The this parameter can be actually that - lexical scoping
ECMAScript 6 standard specification is a long way off
– TypeScript type definition syntax is aligned with ECMAScript 6
Why is knockout.js needed?Declarative bindings
Automatic UI updating
Dependency tracking
Templating
No (or very little) code mixed with html
No html mixed with code
Why are they great together?
Typescript generics add strictness to knockout
Encourages correct usage
Better sense of confidence in the code
Improved readability
Improved testability
The Future of C# - C# 6.0
1. Primary ConstructorsBefore Afterpublic class Point { private int x, y; public Point(int x, int y) { this.x = x; this.y = y; } }
public class Point(int x, int y) { private int x, y; }
The Future of C# - C# 6.0
2. Readonly auto propertiesBefore Afterpublic readonly int x = 3;public int X { get { return x }}
public int X {get; } = 3;
The Future of C# - C# 6.03. Static type using statementsBefore
After
public double A { get { return Math.Round(Math.Sqrt(Math.Abs(someValue))); } }
using System.Math;public double A { get { return Round(Sqrt(Abs(someValue))); } }
The Future of C# - C# 6.04. Property ExpressionsBefore
After
public double Distance { get { return Math.Sqrt(X * X + Y * Y); } }
public double Distance => Math.Sqrt(X * X + Y * Y);
The Future of C# - C# 6.05. Method ExpressionsBefore
After
public double MoveRight(int dx){ return new Point(X + dx, Y);}
public double MoveRight(int dx) => new Point(X + dx, Y);
The Future of C# - C# 6.06. Params for enumerablesBefore
After
Do(someEnumerable.ToArray()); ...
public void Do(params int[] values) { ... }
Do(someEnum); ...public void Do(params IEnumerable<int> points) { ... }
The Future of C# - C# 6.0
7. Inline declarations for out paramsBefore Afterint x; int.TryParse("123", out x);
int.TryParse("123", out int x);
The Future of C# - C# 6.08. Monadic null checkingBefore
After
if (points == null) return -1;var next = points.FirstOrDefault(); if ((next == null) || (next.X == null)) return -1;
return next.X;
return points?.FirstOrDefault()?.X ?? -1;
The Future of C# - C# 6.09. Constructor type parameter inferenceBefore
After
var x = MyClass.Create(1, "X"); ... public static MyClass { public MyClass<T1, T2> Create<T1, T2>(T1 a, T2 b) { return new MyClass<T1, T2>(a, b); }}
var x = new MyClass(1, "X");
Complete electronic evaluation forms on the computers in the hall and enter to win!– Infragistics Ultimate– Telerik DevCraft– JetBrains .NET tools – Semos training vouchers– Pluralsight subscriptions– and many more…