Component Party

import { Component, signal } from "@angular/core";

@Component({
  selector: "app-name",
  template: `<h1>Hello {{ name() }}</h1>`,
})
export class NameComponent {
  name = signal("John");
}

<let/name="John">
<h1>Hello ${name}</h1>

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");
  }
}

<let/name="John">
<script>name = "Jane"</script>
<h1>Hello ${name}</h1>

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);
}

<let/count=10>
<const/doubleCount=count * 2>
<div>${doubleCount}</div>

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

@Component({
  selector: "app-hello-world",
  template: `<h1>Hello world</h1>`,
})
export class HelloWorldComponent {}

<h1>Hello world</h1>

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 {}

<h1.title>I am red</h1>
<button style={ "font-size": "10rem" }>I am a button</button>
<button class=scopedButton>I am a style-scoped button</button>

<style>
  .title {
    color: red;
  }
</style>
<style/{ scopedButton }>
  .scopedButton {
    font-size: 10rem;
  }
</style>

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"];
}

<ul>
  <for|color| of=["red", "green", "blue"]>
    <li>${color}</li>
  </for>
</ul>

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);
  }
}

<let/count=0>
<p>Counter: ${count}</p>
<button onClick() { count++ }>+1</button>

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() });
  }
}

<input/inputElement>
<script>
  inputElement().focus();
</script>

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);
  }
}

static const TRAFFIC_LIGHTS = ["red", "orange", "green"];
<let/lightIndex=0>
<const/light=TRAFFIC_LIGHTS[lightIndex]>

<button onClick() { lightIndex = (lightIndex + 1) % TRAFFIC_LIGHTS.length }>
  Next light
</button>
<p>Light is: ${light}</p>
<p>
  You must
  <if=light === "red">STOP</if>
  <else if=light === "orange">SLOW DOWN</else>
  <else>GO</else>
</p>

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);
  }
}

<let/pageTitle="">
<script>pageTitle = document.title</script>
<p>Page title: ${pageTitle}</p>

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);
  }
}

<let/time=new Date()>
<script>
  const id = setInterval(() => time = new Date(), 1000);
  $signal.onabort = () => clearInterval(id)
</script>
<p>Current time: ${time.toLocaleTimeString()}</p>

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 {}

<UserProfile
  name="John"
  age=20
  favouriteColors=["green", "blue", "red"]
  isAvailable
/>

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);
  }
}

<let/isHappy=true>
<p>Are you happy?</p>
<AnswerButton
  onYes() { isHappy = true }
  onNo() { isHappy = false }
/>
<p style={ "font-size": 50 }>${isHappy ? "😀" : "😥"}</p>

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 {}

<FunnyButton>Click me!</FunnyButton>

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 {}

<FunnyButton/>
<FunnyButton>I got content!</FunnyButton>

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);
}

<let/user={
  id: 1,
  username: "unicorn42",
  email: "[email protected]",
}>
<const/updateUsername(newUsername) {
  user = { ...user, username: newUsername };
}>

<h1>Welcome back, ${user.username}</h1>
<context={ ...user, updateUsername }>
  <UserProfile />
</context>

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("");
}

<let/text="Hello world">
<p>${text}</p>
<input value:=text>

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);
}

<input#is-available
  type="checkbox"
  checked:=input.isAvailable
>
<label for="is-available">Is available</label>

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");
}

<let/picked="red">

<div>Picked: ${picked}</div>
<input#blue-pill
  type="radio"
  value="blue"
  checkedValue:=picked
>
<label for="blue-pill">Blue pill</label>

<input#red-pill
  type="radio"
  value="red"
  checkedValue:=picked
>
<label for="red-pill">Red pill</label>

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 },
  ];
}

static const colors = [
  { id: 1, text: "red" },
  { id: 2, text: "blue" },
  { id: 3, text: "green" },
  { id: 4, text: "gray", isDisabled: true },
];
<let/selectedColorId=2>

<select value:=selectedColorId>
  <for|{ id, isDisabled, text }| of=colors>
    <option value=id disabled=isDisabled>
      ${text}
    </option>
  </for>
</select>

<!doctype html>
<html>
  <body>
    <app-root></app-root>
  </body>
</html>

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./app.js"></script>
  </body>
</html>

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;
  };
}

<try>
  <await|{ results: users }|=fetch("https://randomuser.me/api/?results=3").then(res => res.json())>
    <ul>
      <for|{ picture, name }| of=users>
        <li>
          <img src=picture.thumbnail alt="user">
          <p>${name.first} ${name.last}</p>
        </li>
      </for>
    </ul>
  </await>
  <@placeholder>
    <p>Fetching users...</p>
  </@placeholder>
  <@catch|error|>
    <p>An error occurred while fetching users</p>
  </@catch>
</try>