Angular courses app

List all our challenges for this Angular course

Source code at each step is available through branches ====> HERE

00 - Introduction

Not really a challenge but it's an 'How To' bootstrap the app.

Click here to expand steps

Install NVM (if wanted

Install NVM (https://github.com/creationix/nvm#install-script)
Install a Node Version through NVM

nvm install 7
nvm alias default 7

Ensure node is installed w/ npm

$ node -v
v8.1.0
$ npm -v
5.0.3

Install @angular/cli globally

`npm install -g @angular/cli

Boostrap an angular cli application (updated guide on official website https://cli.angular.io)

ng new myProjectName
cd myProjectName
# Run the application through http://localhost:4200
ng serve

Proposed solution: step-00

01 - Introduction to Components

Main idea: use ng generate and be familiar with basic component

Based on step-00

Proposed solution: step-01

Click here to expand steps

Create a component called header

$ ng generate component header

Add the selector element <app-header></<app-header> into the main HTML app.component.html
Play with template to see what's going on

Add ngx-bootstrap or angular2-materialize
Design a navbar header to display the name of app and links for future routes
Add code between <app-header> and </<app-header>
be genious :D

02 - Templates, Interpolation & Directives

Create a product list view by using ngIf & ngFor directives

Based on step-01

Proposed solution: step-02

Click here to expand steps

Create a component called product-list

ng generate component product/product-list

Inject the created component into the app.component.html

<app-product-list></app-product-list>

Now, add an default products list into our ProductListComponent class (find below a default products array)

products = [
      {
          "id": 1,
          "productName": "Leaf Rake",
          "productCode": "GDN-0011",
          "releaseDate": "March 19, 2016",
          "description": "Leaf rake with 48-inch wooden handle.",
          "price": 19.95,
          "starRating": 3.2,
          "imageUrl": "http://openclipart.org/image/300px/svg_to_png/26215/Anonymous_Leaf_Rake.png"
      },
      {
          "id": 2,
          "productName": "Garden Cart",
          "productCode": "GDN-0023",
          "releaseDate": "March 18, 2016",
          "description": "15 gallon capacity rolling garden cart",
          "price": 32.99,
          "starRating": 4.2,
          "imageUrl": "http://openclipart.org/image/300px/svg_to_png/58471/garden_cart.png"
      },
      {
          "id": 5,
          "productName": "Hammer",
          "productCode": "TBX-0048",
          "releaseDate": "May 21, 2016",
          "description": "Curved claw steel hammer",
          "price": 8.9,
          "starRating": 4.8,
          "imageUrl": "http://openclipart.org/image/300px/svg_to_png/73/rejon_Hammer.png"
      },
      {
          "id": 8,
          "productName": "Saw",
          "productCode": "TBX-0022",
          "releaseDate": "May 15, 2016",
          "description": "15-inch steel blade hand saw",
          "price": 11.55,
          "starRating": 3.7,
          "imageUrl": "http://openclipart.org/image/300px/svg_to_png/27070/egore911_saw.png"
      },
      {
          "id": 10,
          "productName": "Video Game Controller",
          "productCode": "GMG-0042",
          "releaseDate": "October 15, 2015",
          "description": "Standard two-button video game controller",
          "price": 35.95,
          "starRating": 4.6,
          "imageUrl": "http://openclipart.org/image/300px/svg_to_png/120337/xbox-controller_01.png"
      }
  ]

Work on the product-list component template
- Add a table to display product (display image url as text)
- Use *ngIf directive to show the table if there is no product in the array
- Use *ngFor directive on <tr> element to repeat this element as many times as products in the array
Bonus: Create a ProductListDetail component to replace HTML code of *ngFor

03 - Data Binding & Pipes

Use property binding, event binding and two-way binding by using [attr], (event) and [(ngModel)]

Based on step-02

Proposed solution: step-03

Click here to expand steps

Display image as <img src... into the table with a property binding to product.imageUrl
Add a button to show/hide all images on the page (you can handle click by using <button (click)="myPublicMethod()"></button>) The text should be adapted to the current stage: Show the images or Hide the images
Set-up using banana in the box [()] the ngModel on the filter input text (two-way binding)
Create a custom Pipe to reverse a word & use it to display the filter text value.

04 - More on components

Work around component lifecycle

Based on step-03

Proposed solution: step-04

Click here to expand steps

Develop the product pipe and use it into the product-list view (to filter products array).
Use Component lifecycle to console.log a message into the onInit event
Add specific style for the product-list component
Add pipe to products *ngFor (eg: currency, uppercase, etc.)

BONUS

Proposed solution: step-04-bonus

Click here to expand bonus steps

Filter products without pipe. And add rating sort and so on.

05 - Building Nested Component

Create a star component

Based on step-04

Proposed solution: step-05

Click here to expand steps

Create a starComponent which display the rating with stars
Use this component into our productListComponent and place it next to existing product.starRating
Set-up rating input into starComponent
Set-up ratingClicked output into starComponent
Listen ratingClicked event from ProductListComponent

06 - Services and dependency injection

Based on step-05

Proposed solution: step-06

Click here to expand steps

Create a new angular service called ProductService

$ ng generate service shared/models/product

Ensure that it will be declared at our appModule level
Move the IProduct interface and the products array from our productListComponent to this new service
Write a public getProducts method to access to this products array

BONUS: Start to work with Observable

07 - Retrieving data Using HTTP

Move products into a dedicated service

Based on step-06

Proposed solution: step-07

Click here to expand steps

Install json-server as fake backend server

Instal json-server package

npm install --server json-server

Create a folder server
Create a file into created folder called db.json with following content

{
    "products": [
        {
            "id": 1,
            "productName": "Leaf Rake",
            "productCode": "GDN-0011",
            "releaseDate": "March 19, 2016",
            "description": "Leaf rake with 48-inch wooden handle.",
            "price": 19.95,
            "starRating": 3.2,
            "imageUrl": "http://openclipart.org/image/300px/svg_to_png/26215/Anonymous_Leaf_Rake.png"
        },
        {
            "id": 2,
            "productName": "Garden Cart",
            "productCode": "GDN-0023",
            "releaseDate": "March 18, 2016",
            "description": "15 gallon capacity rolling garden cart",
            "price": 32.99,
            "starRating": 4.2,
            "imageUrl": "http://openclipart.org/image/300px/svg_to_png/58471/garden_cart.png"
        },
        {
            "id": 3,
            "productName": "Hammer",
            "productCode": "TBX-0048",
            "releaseDate": "May 21, 2016",
            "description": "Curved claw steel hammer",
            "price": 8.9,
            "starRating": 4.8,
            "imageUrl": "http://openclipart.org/image/300px/svg_to_png/73/rejon_Hammer.png"
        },
        {
            "id": 4,
            "productName": "Saw",
            "productCode": "TBX-0022",
            "releaseDate": "May 15, 2016",
            "description": "15-inch steel blade hand saw",
            "price": 11.55,
            "starRating": 3.7,
            "imageUrl": "http://openclipart.org/image/300px/svg_to_png/27070/egore911_saw.png"
        },
        {
            "id": 5,
            "productName": "Video Game Controller",
            "productCode": "GMG-0042",
            "releaseDate": "October 15, 2015",
            "description": "Standard two-button video game controller",
            "price": 35.95,
            "starRating": 4.6,
            "imageUrl": "http://openclipart.org/image/300px/svg_to_png/120337/xbox-controller_01.png"
        }
    ]
}

Edit the package.json file and add into scripts section the following line

"api": "json-server --watch ./server/db.json"

Then you can run your backend server by type the following command and enjoy http://localhost:3000

npm run api

Just Do It!

Import the HttpModule into the AppModule (if not already done)
1. Install the @angular/http module
2. Import the HttpModule into our AppModule
Inject Http into our ProductService
Update the getProducts() method to make a get call to our API Service http://localhost:3000/products
Use RxJS methods:
1. map to convert the string result into a JSON Object
2. do to console.log the JSON Object
3. catch to attach a method to handle errors
4. Imports

import { Observable } from 'rxjs/Observable'
import 'rxjs/add/operator/mergeMap';

Change into ProductListComponent the way we retrieve the data from our ProductService

BONUS: Do it with BehaviorSubject and Observables

Proposed solution: step-07-bonus

08 - Navigation and Routing Basics

Set-up basic routes to navigate across the application

Based on step-07

Proposed solution: step-08

Click here to expand steps

We'll create 3 main routes: /welcome, /products and /products/:id.

Import the RouterModule into the AppModule (if not already there)
- Install the @angular/router module
```
$ npm install --save @angular/router
```
- Import the RouterModule into our AppModule from installed package
- Use the RouterModule.forRoot([]) syntax to describe the application's routes (Note that RouterModule.forChild([]) is used in angular sub-module of our application to avoid colision)
Create a basic ProductDetailComponent and a WelcomeComponent with angular cli

$ ng generate component modules/welcome
$ ng generate component modules/product/product --flat=true
$ ng generate component modules/product/product-detail

Create manually a ts file ./src/app/app.routes.ts to centralize application routes and set-up our 3 routes: /welcome, /products and /products/:id. In order to organize routes, split products routes into a separated file ./.src/app/modules/product/product.routes.ts with the same syntax.

import { Routes } from '@angular/router';

export const APP_ROUTES: Routes = [
    // Routes
]

Add the <router-outlet></router-outlet> directive into our app.component.html and modules/product/product.component.html to place views
Replace RouterModule.forRoot([]) into app.module.ts to use the routes

import { APP_ROUTES } from './app.routes.ts`

// Some code ...

RouterModule.forRoot(APP_ROUTES)

Replace links into the top bar by using the directive routerLink directive and routerLinkActive to set style on current active link!
Replace links into our ProductListComponent in order to go to the detail page
Add a back button to the ProductDetailComponent.

<button routerLink="../">Back to products</button>

09 - Navigating and Routing Advanced

Enhance our routes to read parameters, set-up guard and resolve data

Based on step-08

Proposed solution: step-09

Click here to expand steps

Write a getProduct(id: number): Observable<IProduct> method into our ProductService

This method looks like the existing getProducts(): Observable<Array<IProduct>> method
Call the following URL instead: http://localhost:3000/product/ID where ID is the requested product id

Set-up a resolve called product in order to get the product object (IProduct) into our ProductDetailComponent

Create a new file injectable called product.resolve.ts

$ ng generate service shared/resolves/product-resolve

Refactor the class name from ProductResolveService to ProductResolve & the filename from product-resolve.service.ts into product.resolve.ts
Import the ProductResolve class into the app.module.ts file and add it into the providers: [] array
The class must implement the interface Resolve<T> imported from the @angular/router module
This interface force you to write a method

class ProductResolve implements Resolve<T> {

    resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<T> | Promise<T> | T {
        // Your code can return an Observable, a Promise or T (T is a generic type, can be number, string, IProduct, etc.)
        // Here T is IProduct
    }

}

Now, we'll write the body of this function
- Retrieve id from URL params
- Return the getProduct(id) from our ProductService to get our Observable<IProduct>

Add the resolve to the wanted route, here into the product.routes.ts

{ path: ':id', component: ProductDetailComponent, resolve: {
    product: ProductResolve
} }

Here you should see when navigating to this route, a request sent to your server!

Retrieve the Observable<IProduct> into our ProductDetailComponent

Import & Inject the ActivatedRoute from @angular/router

import { ActivatedRoute } from '@angular/router';
// …
class ProductDetailComponent implements OnInit {
    constructor(private _route: ActivatedRoute) {} 
}

Retrieve the data observable from ActivatedRoute and assign it to a class variable called product$

this.product$ = this._route.data.map(data => data.product)

Design the ProductDetailComponent HTML in order to display our product$ information. Use the pipe async into the *ngIf

<div *ngIf="product$ | async; let product; else noProductTemplate">
    ID: {{ product.id }}
</div>
<ng-template #noProductTemplate>
    <h4>No product found!</h4>
</ng-template>

Set-up into the HTML a button to go to the next product id (product.id++)
Set-up a guard to check if the given id is a number

Generate a guard by using ng cli

$ ng generate guard --module app.module shared/guards/product-id
// --module will provide automatically the created file into our app.module.ts

Update the code in order to check that the id param is well a number. Display a console.error else and redirect to the product list route

canActivate(
    next: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {
    const id = Number(next.params.id)
    if (isNaN(id) || id > 0) {
        // console.error & redirect
    }
    return true
}

Add the guard to the wanted route, here into the product.routes.ts

{ path: ':id', component: ProductDetailComponent, resolve: {
    product: ProductResolve
}, canActivate: [ProductIdGuard] }

Here we go! 👌

Resolve: It prepares our data for the targeted component

Guard: It active/deactive a route based on custom check (here that the id is a number)

10 - Forms

Edit/Create a product by using forms

Based on step-09

Proposed solution: step-10

Click here to expand steps

Import @angular modules FormsModule & ReactiveFormsModule

Install npm package @angular/forms

$ npm install --save @angular/forms

Import FormsModule & ReactiveFormsModule from @angular/forms into the app.module file

import { Formsmodule, ReactiveFormsModule } from '@angular/forms';
// …
@ngModule({
    //…
    imports: […, FormsModule, ReactiveFormsModule]
})

Display a form to feed all fields about product in HTML template (in ProductDetailComponent)
- You can use ngIf/else syntax

<div *ngIf="myTest; else toto">
  // Displayed if myTest
</div>
<ng-template #toto>
  // Displayed else
</ng-template>

Create the forms in model driven way into the component

Import useful artefact from @angular/forms: FormBuilder, FormGroup, Validators
Inject the FormBuilder
Design the form into the constructor

this.myForm = this._formBuilder.group({
    id: '',
    productName: '',
    ... etc.
})

Create and connect the HTML form to the JS FormGroup by using these directives: FormGroup, FormControlName

<form [formGroup]="myForm">
    //…
    <input type="text" formControlName="productName" />
    //…
</form>

Display into the HTML a submit button which is disabled when the form is INVALID

<input type="submit" [disabled]="myForm.invalid" />

Change the input style based on validation css rules

Create a folder ./src/styles
Create a file ./src/styles/form.css

.ng-valid[required], .ng-valid.required  {
  border-left: 5px solid #42A948; /* green */
}

.ng-invalid:not(form)  {
  border-left: 5px solid #a94442; /* red */
}

Import this new css file into the styles.css

@import url(styles/form.css);

Write the submit method in order to save the product through a call to our server

Create a method saveProduct(product: IProduct): Observable<IProduct> into our ProductService.

return this._http.put(url, payload)
    //…

Create a method onSubmit() into our ProductDetailComponent in order to manage the form submission.

submit() {
    if (this.formProduct.valid) {
        this._productService.saveProduct(this.formProduct.value)
            .subscribe(newProduct => {      // Here we subscribe to do the request
                this.product$ = Observable.from([product])  // We create a new observable from the server response to update our product
                this.toggleMode()
            })
    }
}

Into the ProductDetailTemplate, write a submit button, disabled if the form is invalid

<button type="submit" [disabled]="productForm.invalid">Save</button>

WARNING

Here, we update the product into our component. It works like a charm 'cause we don't display information of this product concurrently in an other part of the view.

If for example, we display current product name into the navbar, after a save, data will be different as we refresh only the ProductDetailComponent product information.

In order to fix that, you cake a look to step-07-bonus which, instead of returns Observables from angular Http service, will manage a collection in-memory and always returns this Observable, with or without filter.

It will allow all our component to be aware of any change on this collection!

We'll do this fix into 11 - Advanced forms

11 - Advanced forms

Based on step-10

Proposed solution: step-11

Click here to expand steps

Update our ProductService to manage a collection in-memory

Use step-07-bonus

class ProductService {

    private products$: BehaviorSubject(Array<IProduct>) = new BehaviorSubject<Array<IProduct>>([])
    private dataStore = {
        products: []
    }

    constructor(private _http: HttpService) {
        this._next() // Emit the dataStore.products event
    }

    getAll() {
        // 1. Do the request call by subscribing
        this._http.get(`URL`).map(res => res.json())
            .subscribe(products => {
                // 2. Sync our dataStore
                this.syncProducts(products)
            })
        // 3. Return the BehaviorSubject as Observable
        return this.products$.asObservable()
    }

    get(id: number) {
        // 1. Same as getAll for one product
        // 2. call _syncProduct instead of _syncProducts
        // 3. Return the BehaviorSubjected as Observable with filter to get the product
        return this.products$.asObservable()
            .flatMap(products => products) // Flatten the Array<IProduct>
            .filter(product => product.id === id)
    }

    private _syncProducts(products: Array<IProduct>) {
        this.dataStore.products = products
        this._next()
    }

    private _syncProduct(product: IProduct) {
        this.dataStore.products.map(storeProduct => {
            return storeProduct.id === product.id ?
                product : storeProduct
        })
        this._next()
    }

    private _next() {
        this.products$.next(this.dataStore.products)
    }

}

Create a custom Validator

Create an empty file into ./src/app/shared/validators/product.validators.ts
Write validator functions into it

export function validProductCode(control:AbstractControl): {[key: string]: any} => {
    const productRegex = /[A-Z]{3}-[0-9]{4}/
    const productCode = control.value
    return productRegex.test(value) ? {'validProductCode': {productCode}} : null;
}

// Function below coming from angular spec
export function forbiddenNameValidator(nameRe: RegExp): ValidatorFn {
  return (control: AbstractControl): {[key: string]: any} => {
    const name = control.value;
    const no = nameRe.test(name);
    return no ? {'forbiddenName': {name}} : null;
  };
}

Add validProductCode to the productCode validators Array into our form

import { validProductCode } from '../../shared/validators/product.validators.ts'
//…
productCode: ['', validProductCode]

Add forbiddenNameValidator to the productName to block a regex (eg: blocked)

import { forbiddenNameValidator } from '../../shared/validators/product.validators.ts'
//…
productName: ['', [//…, forbiddenNameValidator(/blocked/)]]

Display error messages

<div *ngIf="productForm.get('productCode').errors?.validProductCode" class="alert alert-danger">
    Invalid product code.
</div>

12 - Reactive Programming

No challenge here!

13 - Angular 2 set-up revisited

No challenge here!

14 - Unit Testing w/ Jasmine & Karma

No challenge here!

15 - Data Store with @ngrx/store

No challenge here!

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