https://slides.com/rachnerd/deck-1/live#/

npm i -g angular-cli

ng new ws-app --style=scss --prefix=ws

Rachèl Heimbach

Consultant @ Open Value

Hands-on
Angular 2
ChatApp

Content

Components
Services + RxJS
Angular Material
Angular Animations
Routing
Guards
Change Detection
View Encapsulation

Features

const & let
Arrow functions
Class
Value import/export
Promises

const === final === readonly

const foo = 'bar';
foo = 'Something else'; // Error

const obj = {
    foo: 'bar'
};
obj.foo = 'Something else'; // Ok

let, how var should've worked

function varTest() {
  var x = 1;
  if (true) {
    var x = 2;  // same variable!
    console.log(x);  // 2
  }
  console.log(x);  // 2
}

function letTest() {
  let x = 1;
  if (true) {
    let x = 2;  // diff variable
    console.log(x);  // 2
  }
  console.log(x);  // 1
}

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/let

Stop using
var... Use const/let

Arrow functions

//http://es6-features.org/#ExpressionBodies

// ES5
odds  = evens.map(function (v) { return v + 1; });
pairs = evens.map(function (v) { return { even: v, odd: v + 1 }; });
nums  = evens.map(function (v, i) { return v + i; });

// ES6
odds  = evens.map(v => v + 1)
pairs = evens.map(v => ({ even: v, odd: v + 1 }))
nums  = evens.map((v, i) => v + i)

const plusOne = (v) => v + 1;
odds  = evens.map(plusOne)

Arrow function scope

this.foo = 'bar';


function logFoo() {
    console.log(this.foo);
}
logFoo(); // undefined

this.foo = 'bar';


const logFoo = () => {
    console.log(this.foo);
}
logFoo(); // 'bar'

this.foo = 'bar';
var self = this;

function logFoo() {
    console.log(self.foo);
}
logFoo(); // bar

Use
Arrow =>
functions

class

class MyClass {
    constructor() {
        console.log('MyClass initialized');
    }
    foo() {
        console.log('bar');
    }
}

// Syntax sugar for

function MyClass() {
    console.log('MyClass initialized');
}

MyClass.prototype.foo = function () {
    console.log('bar');
}

File scope

// a.js

const privateVariable = 'foo';

export const publicVariable = 'bar';

export default class Foo {
    constructor() {
        console.log('Foo bar');
    }
}

// b.js

import { privateVariable } from './a.js'; 
// Error

import { publicVariable } from './a.js'; 
// 'bar'

import anyName from './a.js';
//  function Foo() {
//      console.log('Foo bar');
//  }

import * as everything from './a.js';
//  {
//      default: Foo(),
//      publicVariable: "bar"
//  }

ES6

const + let are the new var.

Arrow functions can (almost) always replace the old function keyword.

class instead of prototype.

Many more features, mainly syntactic sugar.

http://es6-features.org/

TypeScript

"JavaScript that scales."

TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.

Any browser. Any host. Any OS. Open source.

TypeScript features

Types
Interfaces
Decorators
Access modifiers

Why types in JS?

See errors at compile-time and not just at run-time.
Using strong types prevent more bugs and side effects.
Proper auto completion in smart IDE's.

const addNumbers = (n1: number, n2: number): number => {
    return n1 + n2;
};

addNumbers(1, 2); 
// 3

addNumbers('1', 2); 
// Does not compile

const text: string = addNumbers(1, 2); 
// Does not compile

addN

TS interfaces

Help create data model

Can be used by developers with an OOP approach

interface Person {
    firstName: string;
    lastName: string;
}

const person: Person = {
    firstName: 'Foo'
}
// Does not compile

const person: Person = {
    firstName: 'Foo',
    lastName: 'Bar'
}
// Does compile

interface DoSomething {
    doSomething(): void;
}

class Test implements DoSomething {
}
// Does not compile

class Test implements DoSomething {
    doSomething(): void {}
}
// Does compile

Runtime
===
JavaScript

Keep in mind...

Adding types is optional, but strongly recommended.

@Decorators

Ability to add metadata to variables/methods/classes

Ability to intercept functionality by applying logic before and after method execution.

Access modifiers

Control the visibility of your instance members/methods.

Create public API's in your classes.

class Foo {
    private message: string = 'bar';
    public constructor() {

    }
    public printMessage(): void {
        console.log(this.message);
    }
    private someInternalProcess(): void {
        // Do stuff
    }
}

const foo = new Foo();

foo.

Compiler

The TS compiler needs to be configured for the project.

TS compiler will scan the project and look for d.ts files.

(Most) JavaScript libraries have declaration files available so the TS compiler can understand them.

Tool: typings (on npm)

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es5",
    "outDir": "dist",
    "rootDir": ".",
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "moduleResolution": "node"
  },
  "exclude": [
    "node_modules"
  ],
  "awesomeTypescriptLoaderOptions": {
    "useWebpackText": true
  },
  "compileOnSave": false,
  "buildOnSave": false,
  "atom": {
    "rewriteTsconfig": false
  }
}

Angular 2

Components & Modules
Dependency Injection
Routing
Directives/Pipes
Angular 1

Webcomponents

Custom html element.
Isolated JS + HTML + CSS.
API - Data in/Events out.

Everything

is a

Component

Subtitle

Chat

ChatForm

ChatList

ChatMessage

UserList

User

Component tree

Chat

ChatList

ChatForm

ChatMessage

@Component

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

@Component({
    selector: 'ws-root',
    template: `
        <div>
            Hello world
        </div>
    `
})
export class AppComponent {}

<body>
    <ws-root></ws-root>
</body>

Hello world

Hello World App

/**
 * A basic hello-world Angular 2 app
*/
import { AppComponent } from './app.component';
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';


@NgModule({
    declarations: [ AppComponent ],
    imports: [ BrowserModule ],
    bootstrap: [ AppComponent ],
})
class HelloWorldAppModule {}

platformBrowserDynamic().bootstrapModule(HelloWorldAppModule);

Angular 2

"For web, mobile web, native mobile and native desktop"

NativeScript + Angular 2

Cross platform (Android + iOS) native apps.

Back
to
Components!

@Component

Concepts

Smart

- Communicates with services and binds values to the template.

- Is the parent of one or multiple dumb components.

Dumb

- Has a public API of inputs and outputs.

- Contains no logic.

- Input by databinding.

- Output by event emitting.

App

Chat

ChatList

ChatForm

Smart

Dumb

ChatMessage

Data binding

Event emitting

[Databinding] Input()

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

@Component({
    selector: 'ws-chat-list',
    template: `
        <div *ngFor="let message of messages">
           {{ message.content }}
        </div>
    `
})
export class ChatListComponent {
    @Input() 
    messages: Array<ChatMessage>;
}

<ws-chat-list [messages]="messages"></ws-chat-list>

[ ]???

Template bindings

<input value="Some value" />           <!-- Literal bind -->

<input [value]="text" />               <!-- One way bind -->

<input (change)="handler($event)" />   <!-- Event handler -->

// Component config...
export class MyComponent {
    text: string = 'Some value';
    
    handler(event): void {
        // do something
    }
}

Template references

<input #inputRef (change)="handler(inputRef)" />

// Component config...
export class MyComponent implements AfterViewInit {
    @ViewChild('inputRef')
    inputRef: ElementRef;
    
    ngAfterViewInit() {
        const input: HTMLInputElement = inputRef.nativeElement;
        input.value = 'Initial value';
    }

    handler(input: HTMLInputElement): void {
        input.value = '';
    }
}

(Event) @Output()

import { Component, Output, 
    EventEmitter } from '@angular/core';

@Component({
    selector: 'ws-chat-form',
    template: `
        <form (ngSubmit)="send.emit(message.value)">
            <input #message/>
        </form>
    `
})
export class ChatFormComponent {
    @Output() 
    send: EventEmitter<string> = new EventEmitter();
}

<ws-chat-form (send)="doSomething($event)"></ws-chat-form>

Lifecycle

Angular 2 cheatsheet

https://angular.io/cheatsheet

Recap

Component tree
Databinding downwards
Events upwards
Smart components execute logic
Dumb components receive [data] and emit (events)

App

Chat

ChatList

ChatForm

Smart

Dumb

ChatMessage

DEMO/Break

import { Component, Output, EventEmitter } from '@angular/core';

@Component({
    selector: 'ws-chat-form',
    template: `
        <form (ngSubmit)="send.emit(message.value)">
            <input #message/>
        </form>
    `
})
export class ChatFormComponent {
    @Output() send: EventEmitter<string>
        = new EventEmitter<string>();
}

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

@Component({
    selector: 'ws-chat-list',
    template: `
        <div *ngFor="let message of messages">
           {{ message.content }}
        </div>
    `
})
export class ChatListComponent {
    @Input() messages: Array<ChatMessage>;
}

import { Component } from '@angular/core';
import { ChatMessage } from './shared/chat.model';

@Component({
    selector: 'ws-chat',
    template: `
        <ws-chat-list [messages]="messages"></ws-chat-list>
        <ws-chat-form (send)="onSend($event)"></ws-chat-form>
    `
})
export class ChatComponent {
    messages: Array<ChatMessage> = [];
    onSend(content: string): void {
        this.messages.push(new ChatMessage(content));
    }
}

Databind [messages]

Event (send)

Smart

Dumb

Dependency Injection

Services

||

Values

Service

Instance containing reusable, grouped functionality.

Contains all logic of the application.

Only smart components call service methods that execute logic.

import { Injectable } from '@angular/core';
import { ChatMessage } from './chat-model';

@Injectable()
export class ChatService {
    
    constructor() {}

    getMessages():Array<ChatMessage> {
        return [];
    }
    sendMessage(message: ChatMessage):void {
        return;
    }
}

ng new class chat/shared/chat-service

App

Chat

ChatList

ChatForm

ChatMessage

ChatService

+getMessages()

+sendMessage(message)

Providing

Creates an instance of the dependency.

Injecting

Injects the provided dependency into a component or service.

Provide B so A can inject B

Subtitle

Services
!==
Singleton

App

Chat

ChatList

ChatForm

ChatMessage

ChatService

+getMessages()

+sendMessage(message)

Inject

ChatService?

Nope (throws error)

App

Chat

ChatList

ChatForm

ChatMessage

ChatService

+getMessages()

+sendMessage(message)

Inject

ChatService?

ChatService!

Provide

ChatService

Provide in module

Inject in any other dep.

@NgModule({
    declarations: [ 
        AppComponent,
        ChatComponent
    ],
    imports: [ BrowserModule ],
    bootstrap: [ AppComponent ],
    providers: [ ChatService ]
})
export class AppModule {}

export class ChatComponent {
    constructor(private chatService: ChatService) {
        this.chatService.getMessages();
    }
}

App

Chat

ChatService

+getMessages()

+sendMessage(message)

App. Logic
in
Services

@Component({
    //Config
})
export class ChatComponent {
    messages: Array<ChatMessage> = [];
    onSend(content: string): void {
        this.messages.push({content});
    }
}

LOGIC!

@Component({
    //Config
})
export class ChatComponent implements OnInit {
    messages: Array<ChatMessage>;

    constructor(private chatService: ChatService) {}
    
    ngOnInit() {
        this.messages = this.chatService.getMessages();
    }

    onSend(content: string): void {
        this.chatService.sendMessage(content);
    }
}

LOCAL STATE!

BETTER

HttpModule

export declare class Http {
    //...
    /**
     * Performs a request with `get` http method.
     */
    get(url: string, options?: RequestOptionsArgs): Observable<Response>;
    /**
     * Performs a request with `post` http method.
     */
    post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response>;
    /**
     * Performs a request with `put` http method.
     */
    put(url: string, body: any, options?: RequestOptionsArgs): Observable<Response>;
    /**
     * Performs a request with `delete` http method.
     */
    delete(url: string, options?: RequestOptionsArgs): Observable<Response>;
    //...
}

Observable<Response>?

ChatService

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { ChatMessage } from './chat-model';

@Injectable()
export class ChatService {
    
    constructor(private http: Http) {}

    getMessages():Array<ChatMessage> {
        return [];
    }
    sendMessage(message: ChatMessage):void {
        return;
    }
}

error_handler.js:47ORIGINAL EXCEPTION: No provider for Http!

@NgModule({
    declarations: [ 
        RootComponent,
        ChatComponent
    ],
    imports: [ 
        BrowserModule,
        HttpModule    
    ],
    bootstrap: [ RootComponent ],
    providers: [ ChatService ]
})
export class AppModule {}

ChatService

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { ChatMessage } from './chat-model';

@Injectable()
export class ChatService {
    
    constructor(private http: Http) {}

    getMessages():Observable<Array<ChatMessage>> {
        return this.http
            .get(url)                            
            .map((res: Response) => res.json()); 
    }
    sendMessage(message: ChatMessage):Observable<Response> {
        return this.http
            .post(url, {content: message});
    }
}

@Component({
    //Config
})
export class ChatComponent implements OnInit {
    messages: Array<ChatMessage>;

    constructor(private chatService: ChatService) {}
    
    ngOnInit() {
        this.chatService.getMessages()
            .subscribe(
                (messages: Array<ChatMessage>) => this.messages = messages, 
                (error: Response) => console.error(error),
                () => console.log('Stream closed') //Completed
            );
    }

    onSend(content: string): void {
        this.chatService.sendMessage(content)
            .subscribe(
                (res: Response) => console.log('Sent'),
                (error: Response) => console.error(error),
                () => console.log('Stream closed') //Completed
            )
    }
}

DEMO/Break

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { ChatMessage } from './chat-message.model';
import { Observable } from 'rxjs/Rx';

@Injectable()
export class ChatService {
    
    constructor(private http: Http) {}

    getMessages():Observable<Array<ChatMessage>> {
        return this.http
            .get(url)                            
            .map((res: Response) => res.json());
    }
    sendMessage(message: ChatMessage):Observable<Response> {
        return this.http
            .post(url, {content: message});
    }
}

import { Component, OnInit } from '@angular/core';
import { ChatMessage } from './shared/chat-message.model';
import { ChatService } from './shared/chat-service.service';
import { Http, Response } from '@angular/http';

@Component({
    //Config
})
export class ChatComponent implements OnInit {
    messages: Array<ChatMessage>;

    constructor(private chatService: ChatService) {}
    
    ngOnInit() {
        this.chatService.getMessages()
            .subscribe(
                (messages: Array<ChatMessage>) => this.messages = messages, 
                (error: Response) => console.error(error),
                () => console.log('Stream closed')
            );
    }

    onSend(content: string): void {
        this.chatService.sendMessage(content)
            .subscribe(
                (res: Response) => console.log('Sent'),
                (error: Response) => console.error(error),
                () => console.log('Stream closed')
            )
    }
}

url = ....

Angular CLI

https://github.com/angular/angular-cli

Styling?

Angular 2 Material

Google material design

Install Angular material 2

Add MaterialModule.forRoot() to AppModule's imports
Add to index.html:
Add to styles.scss:

<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">

@import '~@angular/material/core/theming/prebuilt/deeppurple-amber.css';

body {
  margin: 0;
  font-family: Roboto, sans-serif;
}

npm i --save @angular/material

https://github.com/angular/material2

Animations

Animation syntax

@Component({
    selector: 'ws-chat',
    templateUrl: './chat.component.html',
    styleUrls: ['./chat.component.scss'],
    animations: [
        trigger('fadeIn', [
            transition('void => *', [
                style({
                    opacity: 0
                }),
                animate('1s ease-in')
            ])
        ])
    ]
})

<div [@fadeIn]><!--Content--></div>

Animation state

@Component({
    ...
    animations: [
        trigger('heroState', [
            state('inactive', style({
                backgroundColor: '#eee',
                transform: 'scale(1)'
            })),
            state('active',   style({
                backgroundColor: '#cfd8dc',
                transform: 'scale(1.1)'
            })),
            transition('inactive => active', animate('100ms ease-in')),
            transition('active => inactive', animate('100ms ease-out'))
        ])
    ]
})
export class ChatComponent {
    state: string = 'inactive';
    doSomething() {
        this.state = 'active';
    }
}

<div [@heroState]="state"><!--Content--></div>

Animations

Complex animations

animations: [
  trigger('heroState', [
    state('inactive', style({transform: 'translateX(0) scale(1)'})),
    state('active',   style({transform: 'translateX(0) scale(1.1)'})),
    transition('inactive => active', animate('100ms ease-in')),
    transition('active => inactive', animate('100ms ease-out')),
    transition('void => inactive', [
      style({transform: 'translateX(-100%) scale(1)'}),
      animate(100)
    ]),
    transition('inactive => void', [
      animate(100, style({transform: 'translateX(100%) scale(1)'}))
    ]),
    transition('void => active', [
      style({transform: 'translateX(0) scale(0)'}),
      animate(200)
    ]),
    transition('active => void', [
      animate(200, style({transform: 'translateX(0) scale(0)'}))
    ])
  ])
]

Routing

App

Chat

ChatList

ChatForm

ChatMessage

const routes = [
    {
        path: '',
        component: ChatComponent
    }
];

Routing module

const routes = [
    {
        path: '',
        component: ChatComponent
    }
];

//imports
import { RouterModule } from '@angular/router';

@NgModule({
    declarations: [...],
    imports: [
        RouterModule.forRoot(routes),
        ...
    ]
    ...
})

app-component.html

<example-toolbar></example-toolbar>

<router-outlet></router-outlet>

<example-footer></example-footer>

<router-outlet></router-outlet>

<router-outlet name="sidebar"></router-outlet>

<router-outlet name="bottombar"></router-outlet>

[
    {
        path: '',
        component: GeneralChatComponent
    },
    {
        path: 'team',
        component: TeamChatComponent
    },
    {
        path: 'friends',
        component: FriendsComponent,
        outlet: 'sidebar'
    },
    {
        path: 'chat/:userId',
        component: PrivateChatComponent,
        outlet: 'bottombar'
    }
]

<router-outlet>
</router-outlet>

<router-outlet name="sidebar">
</router-outlet>

<router-outlet name="bottombar">
</router-outlet>

:4200/

Main outlet

Bottombar outlet

Sidebar outlet

ChatComponent

Empty

:4200/team

Main outlet

Bottombar outlet

Sidebar outlet

TeamChatComponent

Empty

:4200/(sidebar:friends)

Main outlet

Bottombar outlet

Sidebar outlet

ChatComponent

FriendsComponent

Empty

:4200/

(sidebar:friends//bottombar:chat/123)

Main outlet

Bottombar outlet

Sidebar outlet

ChatComponent

FriendsComponent

PrivateChatComponent

(with user 123)

:4200/team

(sidebar:friends//bottombar:chat/123)

Main outlet

Bottombar outlet

Sidebar outlet

TeamChatComponent

FriendsComponent

PrivateChatComponent

(with user 123)

Lazy routes

Code splitting.
Load other chunks of the application when accessing certain routes.
Less bandwidth usage (initial load).
Fetch code run-time.

{
    path: 'contacts',
    loadChildren: 'contacts.bundle.js'
}

Guards

Subtitle

Guards

CanActivate - to prevent navigation to a route
CanActivateChild - to prevent navigation to a child route
CanDeactivate - to prevent navigation away from the current route
Resolve - to pre-fetch data before activating
CanLoad to prevent asynchronous routing



{
    path: 'root',
    canActivate: [],
    canActivateChild: [],
    canDeActivate: [],
    resolve: {},
    canLoad: [],
    children: [
      {
         path: '',
         component: Chat
      }
    ]
}

CanActivate

@Injectable()
export class CanActivateGuard implements CanActivate {

    constructor(private chatService: ChatService) {

    }

    canActivate(
        route: ActivatedRouteSnapshot, 
        state: RouterStateSnapshot
    ): Observable<boolean>|Promise<boolean>|boolean {
        return true;
    }
}

Don't forget to provide guards to the module!

Break

https://github.com/Rachnerd/chat-app/tree/3-routing

Change detection

Subtitle

View encapsulation

Shadow DOM

RxJS

...is a set of libraries to compose asynchronous and event-based programs using observable collections and Array#extra style composition in JavaScript

RxJS

Observables
Angular 2
Operators
Subjects

Observables?

"Observables are functions that tie an observer to a producer."

Async data?

new Promise((resolve, reject) => {
    setTimeout(() => {
        if(condition) {
            resolve('Done');
        }else {
            reject('Fail');
        }
    }, 1000);
})
.then(res => {})
.catch(err => {});

Observable.create(observer => {
    setTimeout(() => {
        if(condition) {
            observer.next('Done');
            observer.complete(); //close
        }else {
            observer.error('Fail');
        }
    }, 1000);
})
.subscribe(
    res => {},
    err => {},
    ()  => {}
);

Start with the result

Angular Http requests

this.http.get('api/chat')
    .subscribe(
        (messages: Array<ChatMessage>) => {
            console.log(messages)
        },
        (err: Response) => {
            console.error(err)
        }
    );

// [Response Object]
// - status
// - statusText
// - text/json
// - etc...

this.http.get('api/chat')

    .map((res: Response) => res.json())

    .subscribe(
        (messages: Array<ChatMessage>) => {
            console.log(messages)
        },
        (err: Response) => {
            console.error(err)
        }
    );

// [Object, Object, Object]

Messages?

Messages!

Issues while using map? Try:

import 'rxjs/add/operator/map';

rxmarbles

http://rxmarbles.com

Cold

1 time usage, gets cleaned up after subscribe.
Subscribe as many times as you want.

Hot

Doesn't close after subscription.
Subscriptions need to be manually unsubscribed
Caution: memory leaks

State management

Subject

Observable
Subscription

Redux store

Angular 2

By rachnerd

Rachèl Heimbach

Hands-on Angular 2 ChatApp

Content

Features

const === final === readonly

let, how var should've worked

Stop using var... Use const/let

Arrow functions

Arrow function scope

Use Arrow => functions

class

File scope

ES6

TypeScript

"JavaScript that scales."

TypeScript features

Why types in JS?

TS interfaces

Runtime === JavaScript

Keep in mind...

Adding types is optional, but strongly recommended.

@Decorators

Access modifiers

Compiler

Angular 2

Webcomponents

Everything

is a

Component

Subtitle

Component tree

@Component

Hello World App

Angular 2

NativeScript + Angular 2

Back to Components!

@Component

Concepts

Smart

Dumb

[Databinding] Input()

Template bindings

Template references

(Event) @Output()

Lifecycle

Angular 2 cheatsheet

Recap

DEMO/Break

Dependency Injection

Services

||

Values

Service

Providing

Injecting

Provide B so A can inject B

Subtitle

Services !== Singleton

Provide in module

Inject in any other dep.

App. Logic in Services

HttpModule

Observable<Response>?

ChatService

ChatService

DEMO/Break

Angular CLI

Styling?

Angular 2 Material

Google material design

Install Angular material 2

Animations

Animation syntax

Animation state

Animations

Complex animations

Routing

Routing module

app-component.html

:4200/

Hands-on
Angular 2
ChatApp

Stop using
var... Use const/let

Use
Arrow =>
functions

Runtime
===
JavaScript

Back
to
Components!

Services
!==
Singleton

App. Logic
in
Services

Observable
Subscription