Reactivity
Declare state
Angular Renaissance
import { Component, signal } from "@angular/core";
@Component({
selector: "app-name",
template: `<h1>Hello {{ name() }}</h1>`,
})
export class NameComponent {
name = signal("John");
}
Update state
Angular Renaissance
import { Component, signal } from "@angular/core";
@Component({
selector: "app-name",
template: `<h1>Hello {{ name() }}</h1>`,
})
export class NameComponent {
name = signal("John");
constructor() {
this.name.set("Jane");
}
}
Computed state
Angular Renaissance
import { Component, computed, signal } from "@angular/core";
@Component({
selector: "app-double-count",
template: `<div>{{ doubleCount() }}</div>`,
})
export class DoubleCountComponent {
count = signal(10);
doubleCount = computed(() => this.count() * 2);
}
Templating
Minimal template
Styling
Angular Renaissance
import { Component } from "@angular/core";
@Component({
selector: "app-css-style",
template: `
<h1 class="title">I am red</h1>
<button style="font-size: 10rem">I am a button</button>
`,
styles: `
.title {
color: red;
}
`,
})
export class CssStyleComponent {}
Loop
Angular Renaissance
import { Component } from "@angular/core";
@Component({
selector: "app-colors",
template: `
<ul>
@for (color of colors; track color) {
<li>{{ color }}</li>
}
</ul>
`,
})
export class ColorsComponent {
colors = ["red", "green", "blue"];
}
Event click
Angular Renaissance
import { Component, signal } from "@angular/core";
@Component({
selector: "app-counter",
template: `
<p>Counter: {{ count() }}</p>
<button (click)="incrementCount()">+1</button>
`,
})
export class CounterComponent {
count = signal(0);
incrementCount() {
this.count.update((count) => count + 1);
}
}
Dom ref
Angular Renaissance
import {
afterNextRender,
Component,
ElementRef,
viewChild,
} from "@angular/core";
@Component({
selector: "app-input-focused",
template: `<input type="text" #inputRef />`,
})
export class InputFocusedComponent {
inputRef = viewChild.required<ElementRef<HTMLInputElement>>("inputRef");
constructor() {
afterNextRender({ write: () => this.inputRef().nativeElement.focus() });
}
}
Conditional
Angular Renaissance
import { Component, computed, signal } from "@angular/core";
const TRAFFIC_LIGHTS = ["red", "orange", "green"];
@Component({
selector: "app-traffic-light",
template: `
<button (click)="nextLight()">Next light</button>
<p>Light is: {{ light() }}</p>
<p>
You must
@switch (light()) {
@case ("red") {
<span>STOP</span>
}
@case ("orange") {
<span>SLOW DOWN</span>
}
@case ("green") {
<span>GO</span>
}
}
</p>
`,
})
export class TrafficLightComponent {
lightIndex = signal(0);
light = computed(() => TRAFFIC_LIGHTS[this.lightIndex()]);
nextLight() {
this.lightIndex.update((index) => (index + 1) % TRAFFIC_LIGHTS.length);
}
}
import { createSignal, Switch, Match } from "solid-js";
const TRAFFIC_LIGHTS = ["red", "orange", "green"];
export default function TrafficLight() {
const [lightIndex, setLightIndex] = createSignal(0);
const light = () => TRAFFIC_LIGHTS[lightIndex()];
function nextLight() {
setLightIndex((lightIndex() + 1) % TRAFFIC_LIGHTS.length);
}
return (
<>
<button onClick={nextLight}>Next light</button>
<p>Light is: {light()}</p>
<p>
You must
<Switch>
<Match when={light() === "red"}>
<span>STOP</span>
</Match>
<Match when={light() === "orange"}>
<span>SLOW DOWN</span>
</Match>
<Match when={light() === "green"}>
<span>GO</span>
</Match>
</Switch>
</p>
</>
);
}
Lifecycle
On mount
Angular Renaissance
import { Component, OnInit, signal } from "@angular/core";
@Component({
selector: "app-page-title",
template: `<p>Page title: {{ pageTitle() }}</p>`,
})
export class PageTitleComponent implements OnInit {
pageTitle = signal("");
ngOnInit() {
this.pageTitle.set(document.title);
}
}
On unmount
Angular Renaissance
import { Component, OnDestroy, signal } from "@angular/core";
@Component({
selector: "app-time",
template: `<p>Current time: {{ time() }}</p>`,
})
export class TimeComponent implements OnDestroy {
time = signal(new Date().toLocaleTimeString());
timer = setInterval(
() => this.time.set(new Date().toLocaleTimeString()),
1000,
);
ngOnDestroy() {
clearInterval(this.timer);
}
}
import { createSignal, onCleanup } from "solid-js";
export default function Time() {
const [time, setTime] = createSignal(new Date().toLocaleTimeString());
const timer = setInterval(() => {
setTime(new Date().toLocaleTimeString());
}, 1000);
onCleanup(() => clearInterval(timer));
return <p>Current time: {time()}</p>;
}
Component composition
Props
Angular Renaissance
import { Component } from "@angular/core";
import { UserprofileComponent } from "./userprofile.component";
@Component({
selector: "app-root",
imports: [UserprofileComponent],
template: `
<app-userprofile
name="John"
[age]="20"
[favouriteColors]="['green', 'blue', 'red']"
[isAvailable]="true"
/>
`,
})
export class AppComponent {}
Emit to parent
Angular Renaissance
import { Component, signal } from "@angular/core";
import { AnswerButtonComponent } from "./answer-button.component";
@Component({
selector: "app-root",
imports: [AnswerButtonComponent],
template: `
<p>Are you happy?</p>
<app-answer-button (yes)="onAnswerYes()" (no)="onAnswerNo()" />
<p style="font-size: 50px">{{ isHappy() ? "😀" : "😥" }}</p>
`,
})
export class AppComponent {
isHappy = signal(true);
onAnswerYes() {
this.isHappy.set(true);
}
onAnswerNo() {
this.isHappy.set(false);
}
}
import { createSignal } from "solid-js";
import AnswerButton from "./AnswerButton.jsx";
export default function App() {
const [isHappy, setIsHappy] = createSignal(true);
function onAnswerNo() {
setIsHappy(false);
}
function onAnswerYes() {
setIsHappy(true);
}
return (
<>
<p>Are you happy?</p>
<AnswerButton onYes={onAnswerYes} onNo={onAnswerNo} />
<p style={{ "font-size": "50px" }}>{isHappy() ? "😀" : "😥"}</p>
</>
);
}
Slot
Angular Renaissance
import { Component } from "@angular/core";
import { FunnyButtonComponent } from "./funny-button.component";
@Component({
selector: "app-root",
imports: [FunnyButtonComponent],
template: `<app-funny-button>Click me!</app-funny-button>`,
})
export class AppComponent {}
Slot fallback
Angular Renaissance
import { Component } from "@angular/core";
import { FunnyButtonComponent } from "./funny-button.component";
@Component({
selector: "app-root",
imports: [FunnyButtonComponent],
template: `
<app-funny-button />
<app-funny-button>I got content!</app-funny-button>
`,
})
export class AppComponent {}
Context
Angular Renaissance
import { Component, inject } from "@angular/core";
import { UserService } from "./user.service";
import { UserProfileComponent } from "./user-profile.component";
@Component({
imports: [UserProfileComponent],
providers: [UserService],
selector: "app-root",
template: `
<h1>Welcome back, {{ userService.user().username }}</h1>
<app-user-profile />
`,
})
export class AppComponent {
protected userService = inject(UserService);
}
import { createSignal } from "solid-js";
import { UserContext } from "./UserContext";
import UserProfile from "./UserProfile";
export default function App() {
const [user, setUser] = createSignal({
id: 1,
username: "unicorn42",
email: "[email protected]",
});
function updateUsername(newUsername) {
setUser({ ...user(), username: newUsername });
}
return (
<>
<h1>Welcome back, {user().username}</h1>
<UserContext.Provider value={[user, updateUsername]}>
<UserProfile />
</UserContext.Provider>
</>
);
}
Form input
Input text
Angular Renaissance
import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";
@Component({
imports: [FormsModule],
selector: "app-input-hello",
template: `
<p>{{ text() }}</p>
<input [(ngModel)]="text" />
`,
})
export class InputHelloComponent {
text = signal("");
}
Checkbox
Angular Renaissance
import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";
@Component({
imports: [FormsModule],
selector: "app-is-available",
template: `
<input id="is-available" type="checkbox" [(ngModel)]="isAvailable" />
<label for="is-available">Is available</label>
`,
})
export class IsAvailableComponent {
isAvailable = signal(false);
}
import { createSignal } from "solid-js";
export default function IsAvailable() {
const [isAvailable, setIsAvailable] = createSignal(false);
function handleChange() {
setIsAvailable((previousValue) => !previousValue);
}
return (
<>
<input
id="is-available"
type="checkbox"
checked={isAvailable()}
onChange={handleChange}
/>
<label for="is-available">Is available</label>
</>
);
}
Radio
Angular Renaissance
import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";
@Component({
imports: [FormsModule],
selector: "app-pick-pill",
template: `
<div>Picked: {{ picked() }}</div>
<input id="blue-pill" type="radio" value="blue" [(ngModel)]="picked" />
<label for="blue-pill">Blue pill</label>
<input id="red-pill" type="radio" value="red" [(ngModel)]="picked" />
<label for="red-pill">Red pill</label>
`,
})
export class PickPillComponent {
picked = signal("red");
}
import { createSignal } from "solid-js";
export default function PickPill() {
const [picked, setPicked] = createSignal("red");
function handleChange(event) {
setPicked(event.target.value);
}
return (
<>
<div>Picked: {picked()}</div>
<input
id="blue-pill"
checked={picked() === "blue"}
type="radio"
value="blue"
onChange={handleChange}
/>
<label for="blue-pill">Blue pill</label>
<input
id="red-pill"
checked={picked() === "red"}
type="radio"
value="red"
onChange={handleChange}
/>
<label for="red-pill">Red pill</label>
</>
);
}
Select
Angular Renaissance
import { Component, signal } from "@angular/core";
import { FormsModule } from "@angular/forms";
@Component({
imports: [FormsModule],
selector: "app-color-select",
template: `
<select [(ngModel)]="selectedColorId">
@for (let color of colors; track color) {
<option [value]="color.id" [disabled]="color.isDisabled">
{{ color.text }}
</option>
}
</select>
`,
})
export class ColorSelectComponent {
selectedColorId = signal(2);
colors = [
{ id: 1, text: "red" },
{ id: 2, text: "blue" },
{ id: 3, text: "green" },
{ id: 4, text: "gray", isDisabled: true },
];
}
import { createSignal, For } from "solid-js";
const colors = [
{ id: 1, text: "red" },
{ id: 2, text: "blue" },
{ id: 3, text: "green" },
{ id: 4, text: "gray", isDisabled: true },
];
export default function ColorSelect() {
const [selectedColorId, setSelectedColorId] = createSignal(2);
function handleChange(event) {
setSelectedColorId(event.target.value);
}
return (
<select value={selectedColorId()} onChange={handleChange}>
<For each={colors}>
{(color) => (
<option value={color.id} disabled={color.isDisabled}>
{color.text}
</option>
)}
</For>
</select>
);
}
Webapp features
Render app
Fetch data
Angular Renaissance
import { Injectable } from "@angular/core";
import { httpResource } from "@angular/common/http";
@Injectable({ providedIn: "root" })
export class UserService {
readonly usersResource = httpResource<UserResponse>(
() => "https://randomuser.me/api/?results=3",
);
}
export interface UserResponse {
results: User[];
info: any;
}
export interface User {
name: {
title: string;
first: string;
last: string;
};
picture: {
large: string;
medium: string;
thumbnail: string;
};
}
import { createResource, For, Switch, Match } from "solid-js";
async function fetchUsers() {
return (await fetch("https://randomuser.me/api/?results=3")).json();
}
export default function App() {
const [data] = createResource(fetchUsers);
const users = () => data()?.results;
return (
<Switch>
<Match when={data.loading}>
<p>Fetching users...</p>
</Match>
<Match when={data.error}>
<p>An error occurred while fetching users</p>
</Match>
<Match when={users()}>
<ul>
<For each={users()}>
{(user) => (
<li>
<img src={user.picture.thumbnail} alt="user" />
<p>
{user.name.first} {user.name.last}
</p>
</li>
)}
</For>
</ul>
</Match>
</Switch>
);
}