This tutorial lesson demonstrates how to connect the details page to your app.
IMPORTANT: We recommend using your local environment to learn routing.
What you'll learn
At the end of this lesson your application will have support for routing to the details page.
Conceptual preview of routing with route parameters
Each housing location has specific details that should be displayed when a user navigates to the details page for that item. To accomplish this goal, you will need to use route parameters.
Route parameters enable you to include dynamic information as a part of your route URL. To identify which housing location a user has clicked on you will use the id
property of the HousingLocation
type.
-
Using
routerLink
for dynamic navigationIn lesson 10, you added a second route to
src/app/routes.ts
which includes a special segment that identifies the route parameter,id
:'details/:id'
In this case,
:id
is dynamic and will change based on how the route is requested by the code.In
src/app/housing-location/housing-location.component.ts
, add an anchor tag to thesection
element and include therouterLink
directive:Add anchor with a routerLink directive to housing-location.component.ts
import {Component, Input} from '@angular/core';import {CommonModule} from '@angular/common';import {HousingLocation} from '../housinglocation';import {RouterModule} from '@angular/router';@Component({ selector: 'app-housing-location', imports: [CommonModule, RouterModule], template: ` <section class="listing"> <img class="listing-photo" [src]="housingLocation.photo" alt="Exterior photo of {{ housingLocation.name }}" crossorigin /> <h2 class="listing-heading">{{ housingLocation.name }}</h2> <p class="listing-location">{{ housingLocation.city }}, {{ housingLocation.state }}</p> <a [routerLink]="['/details', housingLocation.id]">Learn More</a> </section> `, styleUrls: ['./housing-location.component.css'],})export class HousingLocationComponent { @Input() housingLocation!: HousingLocation;}
The
routerLink
directive enables Angular's router to create dynamic links in the application. The value assigned to therouterLink
is an array with two entries: the static portion of the path and the dynamic data.For the
routerLink
to work in the template, add a file level import ofRouterLink
andRouterOutlet
from '@angular/router', then update the componentimports
array to include bothRouterLink
andRouterOutlet
.At this point you can confirm that the routing is working in your app. In the browser, refresh the home page and click the "Learn More" button for a housing location.
-
Get route parameters
In this step, you will get the route parameter in the
DetailsComponent
. Currently, the app displaysdetails works!
. Next you'll update the code to display theid
value passed using the route parameters.In
src/app/details/details.component.ts
update the template to import the functions, classes and services that you'll need to use in theDetailsComponent
:Update file level imports
import {Component, inject} from '@angular/core';import {CommonModule} from '@angular/common';import {ActivatedRoute} from '@angular/router';import {HousingService} from '../housing.service';import {HousingLocation} from '../housinglocation';@Component({ selector: 'app-details', imports: [CommonModule], template: ` <article> <img class="listing-photo" [src]="housingLocation?.photo" alt="Exterior photo of {{ housingLocation?.name }}" crossorigin /> <section class="listing-description"> <h2 class="listing-heading">{{ housingLocation?.name }}</h2> <p class="listing-location">{{ housingLocation?.city }}, {{ housingLocation?.state }}</p> </section> <section class="listing-features"> <h2 class="section-heading">About this housing location</h2> <ul> <li>Units available: {{ housingLocation?.availableUnits }}</li> <li>Does this location have wifi: {{ housingLocation?.wifi }}</li> <li>Does this location have laundry: {{ housingLocation?.laundry }}</li> </ul> </section> </article> `, styleUrls: ['./details.component.css'],})export class DetailsComponent { route: ActivatedRoute = inject(ActivatedRoute); housingService = inject(HousingService); housingLocation: HousingLocation | undefined; constructor() { const housingLocationId = Number(this.route.snapshot.params['id']); this.housingLocation = this.housingService.getHousingLocationById(housingLocationId); }}
Update the
template
property of the@Component
decorator to display the valuehousingLocationId
:template: `<p>details works! {{ housingLocationId }}</p>`,
Update the body of the
DetailsComponent
class with the following code:export class DetailsComponent { route: ActivatedRoute = inject(ActivatedRoute); housingLocationId = -1; constructor() { this.housingLocationId = Number(this.route.snapshot.params['id']); } }
This code gives the
DetailsComponent
access to theActivatedRoute
router feature that enables you to have access to the data about the current route. In theconstructor
, the code converts theid
parameter acquired from the route from a string to a number.Save all changes.
In the browser, click on one of the housing location's "Learn More" links and confirm that the numeric value displayed on the page matches the
id
property for that location in the data.
-
Customize the
DetailComponent
Now that routing is working properly in the application this is a great time to update the template of the
DetailsComponent
to display the specific data represented by the housing location for the route parameter.To access the data you will add a call to the
HousingService
.Update the template code to match the following code:
Update the DetailsComponent template in src/app/details/details.component.ts
import {Component, inject} from '@angular/core';import {CommonModule} from '@angular/common';import {ActivatedRoute} from '@angular/router';import {HousingService} from '../housing.service';import {HousingLocation} from '../housinglocation';@Component({ selector: 'app-details', imports: [CommonModule], template: ` <article> <img class="listing-photo" [src]="housingLocation?.photo" alt="Exterior photo of {{ housingLocation?.name }}" crossorigin /> <section class="listing-description"> <h2 class="listing-heading">{{ housingLocation?.name }}</h2> <p class="listing-location">{{ housingLocation?.city }}, {{ housingLocation?.state }}</p> </section> <section class="listing-features"> <h2 class="section-heading">About this housing location</h2> <ul> <li>Units available: {{ housingLocation?.availableUnits }}</li> <li>Does this location have wifi: {{ housingLocation?.wifi }}</li> <li>Does this location have laundry: {{ housingLocation?.laundry }}</li> </ul> </section> </article> `, styleUrls: ['./details.component.css'],})export class DetailsComponent { route: ActivatedRoute = inject(ActivatedRoute); housingService = inject(HousingService); housingLocation: HousingLocation | undefined; constructor() { const housingLocationId = Number(this.route.snapshot.params['id']); this.housingLocation = this.housingService.getHousingLocationById(housingLocationId); }}
Notice that the
housingLocation
properties are being accessed with the optional chaining operator?
. This ensures that if thehousingLocation
value is null or undefined the application doesn't crash.Update the body of the
DetailsComponent
class to match the following code:Update the DetailsComponent class in src/app/details/details.component.ts
import {Component, inject} from '@angular/core';import {CommonModule} from '@angular/common';import {ActivatedRoute} from '@angular/router';import {HousingService} from '../housing.service';import {HousingLocation} from '../housinglocation';@Component({ selector: 'app-details', imports: [CommonModule], template: ` <article> <img class="listing-photo" [src]="housingLocation?.photo" alt="Exterior photo of {{ housingLocation?.name }}" crossorigin /> <section class="listing-description"> <h2 class="listing-heading">{{ housingLocation?.name }}</h2> <p class="listing-location">{{ housingLocation?.city }}, {{ housingLocation?.state }}</p> </section> <section class="listing-features"> <h2 class="section-heading">About this housing location</h2> <ul> <li>Units available: {{ housingLocation?.availableUnits }}</li> <li>Does this location have wifi: {{ housingLocation?.wifi }}</li> <li>Does this location have laundry: {{ housingLocation?.laundry }}</li> </ul> </section> </article> `, styleUrls: ['./details.component.css'],})export class DetailsComponent { route: ActivatedRoute = inject(ActivatedRoute); housingService = inject(HousingService); housingLocation: HousingLocation | undefined; constructor() { const housingLocationId = Number(this.route.snapshot.params['id']); this.housingLocation = this.housingService.getHousingLocationById(housingLocationId); }}
Now the component has the code to display the correct information based on the selected housing location. The
constructor
now includes a call to theHousingService
to pass the route parameter as an argument to thegetHousingLocationById
service function.Copy the following styles into the
src/app/details/details.component.css
file:Add styles for the DetailsComponent
.listing-photo { height: 600px; width: 50%; object-fit: cover; border-radius: 30px; float: right;}.listing-heading { font-size: 48pt; font-weight: bold; margin-bottom: 15px;}.listing-location::before { content: url('/assets/location-pin.svg') / '';}.listing-location { font-size: 24pt; margin-bottom: 15px;}.listing-features > .section-heading { color: var(--secondary-color); font-size: 24pt; margin-bottom: 15px;}.listing-features { margin-bottom: 20px;}.listing-features li { font-size: 14pt;}li { list-style-type: none;}.listing-apply .section-heading { font-size: 18pt; margin-bottom: 15px;}label, input { display: block;}label { color: var(--secondary-color); font-weight: bold; text-transform: uppercase; font-size: 12pt;}input { font-size: 16pt; margin-bottom: 15px; padding: 10px; width: 400px; border-top: none; border-right: none; border-left: none; border-bottom: solid .3px;}@media (max-width: 1024px) { .listing-photo { width: 100%; height: 400px; }}
Save your changes.
In the browser refresh the page and confirm that when you click on the "Learn More" link for a given housing location the details page displays the correct information based on the data for that selected item.
-
Add navigation to the
HomeComponent
In a previous lesson you updated the
AppComponent
template to include arouterLink
. Adding that code updated your app to enable navigation back to theHomeComponent
whenever the logo is clicked.Confirm that your code matches the following:
Add routerLink to AppComponent
import {Component} from '@angular/core';import {HomeComponent} from './home/home.component';import {RouterLink, RouterOutlet} from '@angular/router';@Component({ selector: 'app-root', imports: [HomeComponent, RouterLink, RouterOutlet], template: ` <main> <a [routerLink]="['/']"> <header class="brand-name"> <img class="brand-logo" src="/assets/logo.svg" alt="logo" aria-hidden="true" /> </header> </a> <section class="content"> <router-outlet></router-outlet> </section> </main> `, styleUrls: ['./app.component.css'],})export class AppComponent { title = 'homes';}
Your code may already be up-to-date but confirm to be sure.
Summary: In this lesson you added routing to show details pages.
You now know how to:
- use route parameters to pass data to a route
- use the
routerLink
directive to use dynamic data to create a route - use route parameter to retrieve data from the
HousingService
to display specific housing location information.
Really great work so far.
For more information about the topics covered in this lesson, visit: