响应式

声明状态

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  selector: "app-name",
  template: `<h1>你好 {{ name() }}</h1>`,
})
export class NameComponent {
  name = signal("张三");
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";

export default class NameComponent extends Component {
  name = "张三";

  <template>
    <h1>你好 {{this.name}}</h1>
  </template>
}

更新状态

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  selector: "app-name",
  template: `<h1>你好 {{ name() }}</h1>`,
})
export class NameComponent {
  name = signal("张三");

  constructor() {
    this.name.set("李四");
  }
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

export default class CounterComponent extends Component {
  @tracked name = "张三";

  constructor(owner, args) {
    super(owner, args);

    this.name = "李四";
  }

  <template>
    <h1>你好 {{this.name}}</h1>
  </template>
}

计算属性

Angular Renaissance 标志 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);
}

Ember Polaris 标志 Ember Polaris

import Component, { tracked } from "@glimmer/component";

export default class DoubleCount extends Component {
  @tracked count = 10;

  get doubleCount() {
    return this.count * 2;
  }

  <template>
    <div>{{this.doubleCount}}</div>
  </template>
}

模板语法

最简模板

Angular Renaissance 标志 Angular Renaissance

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

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

Ember Polaris 标志 Ember Polaris

<template>
  <h1>你好,世界</h1>
</template>

样式

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  selector: "app-css-style",
  template: `
    <h1 class="title">我是红色的</h1>
    <button style="font-size: 10rem">我是一个按钮</button>
  `,
  styles: `
    .title {
      color: red;
    }
  `,
})
export class CssStyleComponent {}

Ember Polaris 标志 Ember Polaris

<template>
  <h1 class="title">我是红色的</h1>
  <button style="font-size: 10rem;">我是一个按钮</button>

  <style>
    .title {
      color: red;
    }
  </style>
</template>

DOM循环

Angular Renaissance 标志 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 = ["红", "绿", "蓝"];
}

Ember Polaris 标志 Ember Polaris

const colors = ["红", "绿", "蓝"];

<template>
  <ul>
    {{#each colors as |color|}}
      <li>{{color}}</li>
    {{/each}}
  </ul>
</template>

点击事件

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  selector: "app-counter",
  template: `
    <p>计数器: {{ count() }}</p>
    <button (click)="incrementCount()">+1</button>
  `,
})
export class CounterComponent {
  count = signal(0);

  incrementCount() {
    this.count.update((count) => count + 1);
  }
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

export default class Counter extends Component {
  @tracked count = 0;

  incrementCount = () => this.count++;

  <template>
    <p>计数器: {{this.count}}</p>
    <button {{on "click" this.incrementCount}}>+1</button>
  </template>
}

DOM引用

Angular Renaissance 标志 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() });
  }
}

Ember Polaris 标志 Ember Polaris

import { modifier } from "ember-modifier";

const autofocus = modifier((element) => element.focus());

<template>
  <input {{autofocus}} />
</template>

条件渲染

Angular Renaissance 标志 Angular Renaissance

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

const TRAFFIC_LIGHTS = ["红灯", "黄灯", "绿灯"];

@Component({
  selector: "app-traffic-light",
  template: `
    <button (click)="nextLight()">下一个灯</button>
    <p>现在亮着的是: {{ light() }}</p>
    <p>
      你应该
      @switch (light()) {
        @case ("红灯") {
          <span>停下</span>
        }
        @case ("黄灯") {
          <span>慢行</span>
        }
        @case ("绿灯") {
          <span>赶紧走</span>
        }
      }
    </p>
  `,
})
export class TrafficLightComponent {
  lightIndex = signal(0);

  light = computed(() => TRAFFIC_LIGHTS[this.lightIndex()]);

  nextLight() {
    this.lightIndex.update((index) => (index + 1) % TRAFFIC_LIGHTS.length);
  }
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

const TRAFFIC_LIGHTS = ["红灯", "黄灯", "绿灯"];

export default class TrafficLight extends Component {
  @tracked lightIndex = 0;

  get light() {
    return TRAFFIC_LIGHTS[this.lightIndex];
  }

  nextLight = () => {
    this.lightIndex = (this.lightIndex + 1) % TRAFFIC_LIGHTS.length;
  };

  <template>
    <button {{on "click" this.nextLight}}>下一个灯</button>
    <p>现在亮着的是: {{this.light}}</p>
    <p>
      你应该
      {{#if (eq this.light "红灯")}}
        停下
      {{else if (eq this.light "黄灯")}}
        慢行
      {{else if (eq this.light "绿灯")}}
        赶紧走
      {{/if}}
    </p>
  </template>
}

生命周期

组件加载时

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  selector: "app-page-title",
  template: `<p>页面标题: {{ pageTitle() }}</p>`,
})
export class PageTitleComponent implements OnInit {
  pageTitle = signal("");

  ngOnInit() {
    this.pageTitle.set(document.title);
  }
}

Ember Polaris 标志 Ember Polaris

const pageTitle = () => document.title;

<template>
  <p>页面标题: {{(pageTitle)}}</p>
</template>

组件卸载时

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  selector: "app-time",
  template: `<p>当前时间: {{ 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);
  }
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";
import { registerDestructor } from "@ember/destroyable";

export default class Time extends Component {
  @tracked time = new Date().toLocaleTimeString();

  constructor(owner, args) {
    super(owner, args);

    let timer = setInterval(() => {
      this.time = new Date().toLocaleTimeString();
    }, 1000);

    registerDestructor(this, () => clearInterval(timer));
  }

  <template>
    <p>当前时间: {{this.time}}</p>
  </template>
}

组件组合

组件Props传参

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";
import { UserprofileComponent } from "./userprofile.component";

@Component({
  selector: "app-root",
  imports: [UserprofileComponent],
  template: `
    <app-userprofile
      name="张三"
      [age]="20"
      [favouriteColors]="['green', 'blue', 'red']"
      [isAvailable]="true"
    />
  `,
})
export class AppComponent {}

Ember Polaris 标志 Ember Polaris

import UserProfile from "./user-profile.gjs";

const favoriteColors = ["green", "blue", "red"];

<template>
  <UserProfile
    @name="张三"
    @age={{20}}
    @favouriteColors={{favoriteColors}}
    @isAvailable={{true}}
  />
</template>

向父组件emit事件

Angular Renaissance 标志 Angular Renaissance

import { Component, signal } from "@angular/core";
import { AnswerButtonComponent } from "./answer-button.component";

@Component({
  selector: "app-root",
  imports: [AnswerButtonComponent],
  template: `
    <p>你快乐吗?</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);
  }
}

Ember Polaris 标志 Ember Polaris

<template>
  <button {{on "click" @onYes}}> 是的! </button>
  <button {{on "click" @onNo}}> 不是! </button>
</template>

slot插槽

Angular Renaissance 标志 Angular Renaissance

import { Component } from "@angular/core";
import { FunnyButtonComponent } from "./funny-button.component";

@Component({
  selector: "app-root",
  imports: [FunnyButtonComponent],
  template: `<app-funny-button>点我!</app-funny-button>`,
})
export class AppComponent {}

Ember Polaris 标志 Ember Polaris

import FunnyButton from "./funny-button";

<template>
  <FunnyButton>点我!</FunnyButton>
</template>

slot插槽内容

Angular Renaissance 标志 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>这是传到slot的内容!</app-funny-button>
  `,
})
export class AppComponent {}

Ember Polaris 标志 Ember Polaris

import FunnyButton from "./funny-button";

<template>
  <FunnyButton />
  <FunnyButton>这是传到slot的内容!</FunnyButton>
</template>

上下文

Angular Renaissance 标志 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>欢迎回来, {{ userService.user().username }}</h1>
    <app-user-profile />
  `,
})
export class AppComponent {
  protected userService = inject(UserService);
}

Ember Polaris 标志 Ember Polaris

import UserProfile from "./user-profile";

<template>
    <UserProfile />
</template>

表单输入

输入框

Angular Renaissance 标志 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("");
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

export default class InputHello extends Component {
  @tracked text = "你好世界";

  handleInput = (event) => (this.text = event.target.value);

  <template>
    <p>{{this.text}}</p>
    <input value={{this.text}} {{on "input" this.handleInput}} />
  </template>
}

复选框

Angular Renaissance 标志 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">这是一个checkbox</label>
  `,
})
export class IsAvailableComponent {
  isAvailable = signal(false);
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

export default class InputHello extends Component {
  @tracked isAvailable = false;

  handleChange = (event) => (this.isAvailable = event.target.checked);

  <template>
    <input
      id="is-available"
      type="checkbox"
      checked={{this.isAvailable}}
      {{on "change" this.handleChange}}
    />
    <label for="is-available">这是一个checkbox</label>
  </template>
}

单选框

Angular Renaissance 标志 Angular Renaissance

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

@Component({
  imports: [FormsModule],
  selector: "app-pick-pill",
  template: `
    <div>你选择了: {{ picked() }}</div>

    <input id="blue-pill" type="radio" value="blue" [(ngModel)]="picked" />
    <label for="blue-pill">蓝色</label>

    <input id="red-pill" type="radio" value="red" [(ngModel)]="picked" />
    <label for="red-pill">红色</label>
  `,
})
export class PickPillComponent {
  picked = signal("red");
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

export default class PickPill extends Component {
  @tracked picked = "red";

  handleChange = (event) => (this.picked = event.target.value);

  <template>
    <div>你选择了: {{this.picked}}</div>

    <input
      id="blue-pill"
      type="radio"
      value="blue"
      checked={{eq this.picked "blue"}}
      {{on "change" this.handleChange}}
    />
    <label htmlFor="blue-pill">蓝色</label>

    <input
      id="red-pill"
      type="radio"
      value="red"
      checked={{eq this.picked "red"}}
      {{on "change" this.handleChange}}
    />
    <label htmlFor="red-pill">红色</label>
  </template>
}

选择器

Angular Renaissance 标志 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: "红" },
    { id: 2, text: "蓝" },
    { id: 3, text: "绿" },
    { id: 4, text: "灰", isDisabled: true },
  ];
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

export default class ColorSelect extends Component {
  @tracked selectedColorId = 2;

  select = (event) => (this.selectedColorId = event.target.value);

  isSelected = (colorId) => this.selectedColorId === colorId;

  colors = [
    { id: 1, text: "红" },
    { id: 2, text: "蓝" },
    { id: 3, text: "绿" },
    { id: 4, text: "灰", isDisabled: true },
  ];

  <template>
    <select {{on "change" this.select}}>
      {{#each this.colors as |color|}}
        <option
          value={{color.id}}
          disabled={{color.isDisabled}}
          selected={{this.isSelected color.id}}
        >
          {{color.text}}
        </option>
      {{/each}}
    </select>
  </template>
}

Web应用特性

渲染应用

Angular Renaissance 标志 Angular Renaissance

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

Ember Polaris 标志 Ember Polaris

<!doctype html>
<html>
  <body>
    <script type="module" src="./index.js"></script>
  </body>
</html>

fetch获取数据

Angular Renaissance 标志 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;
  };
}

Ember Polaris 标志 Ember Polaris

import Component from "@glimmer/component";
import { tracked } from "@glimmer/tracking";

class State {
  @tracked isLoading = false;
  @tracked error = null;
  @tracked data = null;
}

function fetchUsers() {
  let state = new State();
  
  async function fetchData() {
    try {
      let response = await fetch("https://randomuser.me/api/?results=3");
      let { results: users } = await response.json();
      state.data = users;
      state.error = null;
    } catch (err) {
      state.data = null;
      state.error = err;
    }
    state.isLoading = false;
  }
  
  fetchData();
  return state;
}

export default class App extends Component {
  <template>
    {{#let (this.fetchUsers) as |request|}}
      {{#if request.isLoading}}
        <p>正在获取用户信息……</p>
      {{else if request.error}}
        <p>获取用户信息出错</p>
      {{else}}
        <ul>
          {{#each request.data as |user|}}
            <li>
              <img src={{user.picture.thumbnail}} alt="user" />
              <p>{{user.name.first}} {{user.name.last}}</p>
            </li>
          {{/each}}
        </ul>
      {{/if}}
    {{/let}}
  </template>
}