tedhagos

# update brew because `brew update` is broken after updating to El Capitan
cd `brew --prefix`
git fetch origin
git reset --hard origin/master
sudo shutdown -r now # restart the computer


# open terminal and run the following
brew update
brew cleanup

tedhagos

Installation

On the same folder where you will download 'app.js', do these things

npm init -y
npm install --save express cors
npm install -g nodemon

tedhagos

1. Create an angular project, when asked for Angular routing support, say "YES"
2. Create routes in app.module.ts
3. Write the [routerLinks] in app.component.html
4. Writer the in app.component.html
5. Make sure there is a line in the head section of app.component.html

tedhagos

1. On the root module (app.module.ts)

   • import the HttpClientModule
   • put it in the imports section

2. On the app.service.ts

   • import the HttpClient from @angular/common/http
   • Inject it in the constructor of the service

3. In angular.json

• Under architect > build > options > assets, add "src/api"

tedhagos

<h1>{{ title }}</h1>

<button (click)="subscribe()">
  Subscribe
</button>

tedhagos

To create the project

ng new parentchild
ng g c childone

cd parentchild
npm install --save bootstrap

tedhagos

<h1>{{ title }}</h1>

<strong>Can you guess a number betwee 1 to 100?</strong>
<p>
  <input placeholder="type an integer" [(ngModel)]="guess">
</p>
<button (click)="guessTheNumber()">
  Guess the number
</button>
<p></p>

tedhagos

class MainActivity : AppCompatActivity() {
  val Log = Logger.getLogger(MainActivity::class.java.name)

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
  }

  override fun onCreateOptionsMenu(menu: Menu?): Boolean {
    Log.info("onCreateOptionsMenu")

tedhagos

// Warning, this code won't  compile in Kotlin
// it has problemss. Can you spot which line won't compile?

fun main(args: Array<String>) {
  val mlist = listOf(Programmer("Ted"), Tester("Steph")) // (1)
  val mprogs = mlist.typeOf<Programmer>() // (2)

  mprogs.forEach { // (3)
    println("${it.toString()} : ${it.javaClass.simpleName}")
  }

tedhagos

Let’s deal with the meaning of reify first. It means to make something real, and the reason we’re using reify and generics on the same statement is because of Java’s type erasure.

Type erasure means exactly what you think it means. Java, and Kotlin as well, erases generic type information at runtime. There are good reasons for this, but unfortunately, we’re not going to discuss those reasons why the language design is like that — but we will discuss its effects. Because of type erasure, you can’t perform any reflection activity and you can’t do any runtime check on a type. So, the following code won't work.

fun checkInfo(items:List<Any>) { 
    if(items is List<String>) {   // (1)
      println("item is a list of Strings")
    }
 }