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");
}

Mithril 标志 Mithril

import m from "mithril";

export default function Name() {
  let name = "张三";

  return {
    view: () => m("h1", `你好 ${name}`),
  };
}

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");
  }
}

Mithril 标志 Mithril

import m from "mithril";

export default function Name() {
  let name = "张三";
  name = "李四";
  return {
    view: () => m("h1", `你好 ${name}`),
  };
}

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);
}

Mithril 标志 Mithril

import m from "mithril";

export default function DoubleCount() {
  let count = 10;
  let doubleCount = count * 2;
  return {
    view: () => m("div", doubleCount),
  };
}

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 {}

Mithril 标志 Mithril

import m from "mithril";

export default function HelloWorld() {
  return {
    view: () => m("h1", "你好,世界"),
  };
}

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 {}

Mithril 标志 Mithril

import "./style.css";
import m from "mithril";

export default function CssStyle() {
  return {
    view: () =>
      m(
        "div",
        m("h1.title", "我是红色的"),
        m("button", { style: { fontSize: "10rem" } }, "我是一个按钮"),
      ),
  };
}

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"];
}

Mithril 标志 Mithril

import m from "mithril";

export default function Colors() {
  const colors = ["红", "绿", "蓝"];
  return {
    view: () =>
      m(
        "ul",
        colors.map((color, idx) => m("li", { key: idx }, color)),
      ),
  };
}

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);
  }
}

Mithril 标志 Mithril

import m from "mithril";

export default function Counter() {
  let count = 0;
  const incrementCount = () => (count = count + 1);
  return {
    view: () =>
      m(
        "div",
        m("p", `计数器: ${count}`),
        m("button", { onclick: incrementCount }, "+1"),
      ),
  };
}

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() });
  }
}

Mithril 标志 Mithril

import m from "mithril";

export default function InputFocused() {
  let value = "";
  return {
    view: () =>
      m("input", {
        oncreate: ({ dom }) => dom.focus(),
        type: "text",
        value,
        oninput: (e) => (value = e.target.value),
      }),
  };
}

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);
  }
}

Mithril 标志 Mithril

import m from "mithril";
const TRAFFIC_LIGHTS = ["红灯", "黄灯", "绿灯"];

export default function TrafficLight() {
  let lightIndex = 0;
  let currentLight = () => TRAFFIC_LIGHTS[lightIndex];

  const nextLight = () => (lightIndex + 1) % TRAFFIC_LIGHTS.length;

  const instructions = () => {
    switch (currentLight()) {
      case "红灯":
        return "停下";
      case "黄灯":
        return "慢行";
      case "绿灯":
        return "赶紧走";
    }
  };

  return {
    view: () =>
      m(
        "div",
        m("button", { onclick: nextLight }, "下一个灯"),
        m("p", `现在亮着的是: ${currentLight()}`),
        m("p", "你应该 ", m("span", instructions())),
      ),
  };
}

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);
  }
}

Mithril 标志 Mithril

import m from "mithril";

export default function PageTitle() {
  return {
    view: () => m("p", `页面标题: ${document.title}`),
  };
}

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);
  }
}

Mithril 标志 Mithril

import m from "mithril";

export default function Time() {
  let time = new Date().toLocaleTimeString();

  const timer = setInterval(() => {
    time = new Date().toLocaleTimeString();
    m.redraw();
  }, 1000);

  return {
    view: () => m("p", `当前时间: ${time}`),
    onremove: () => clearInterval(timer),
  };
}

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 {}

Mithril 标志 Mithril

import m from "mithril";
import UserProfile from "./UserProfile.js";

export default function App() {
  return {
    view: () =>
      m(UserProfile, {
        name: "张三",
        age: 20,
        favouriteColors: ["green", "blue", "red"],
        isAvailable: true,
      }),
  };
}

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);
  }
}

Mithril 标志 Mithril

import m from "mithril";
export const AnswerButton = ({ attrs: { onYes, onNo } }) => ({
  view: () =>
    m(
      "div",
      m("button", { onclick: onYes }, "是的!"),
      m("button", { onclick: onNo }, "不是!"),
    ),
});

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 {}

Mithril 标志 Mithril

import m from "mithril";
import { FunnyButton } from "./FunnyButton.jsx";

export default function App() {
  return {
    view: () => m(FunnyButton, "点我!"),
  };
}

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 {}

Mithril 标志 Mithril

import m from "mithril";
import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return {
    view: () => m("", m(FunnyButton), m(FunnyButton, "这是传到slot的内容!")),
  };
}

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);
}

Mithril 标志 Mithril

import m from "mithril";
import UserProfile from "./UserProfile";

export default function App() {
  const user = {
    id: 1,
    username: "abcdefg",
    email: "[email protected]",
  };

  const updateUsername = (username) => (user.username = username);

  return {
    view: () =>
      m(
        "",
        m("h1", `欢迎回来, ${user.username}`),
        m(UserProfile, { user, updateUsername }),
      ),
  };
}

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("");
}

Mithril 标志 Mithril

import m from "mithril";

export default function InputHello() {
  let text = "你好世界";
  const handleChange = ({ target: { value } }) => (text = value);

  return {
    view: () =>
      m("", m("p", text), m("input", { value: text, onchange: handleChange })),
  };
}

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);
}

Mithril 标志 Mithril

import m from "mithril";

export default function IsAvailable() {
  let isAvailable = false;
  const onUpdate = () => (isAvailable = !isAvailable);

  return {
    view: () =>
      m(
        "",

        m("input", {
          id: "is-available",
          type: "checkbox",
          checked: isAvailable,
          onchange: onUpdate,
        }),
        m("label", { for: "is-available" }, "这是一个checkbox"),
      ),
  };
}

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");
}

Mithril 标志 Mithril

import m from "mithril";

export default function PickPill() {
  let picked = "red";
  let pills = ["red", "green", "blue"];
  const handleChange = ({ target: { value } }) => (picked = value);

  return {
    view: () =>
      m(
        "",
        m("", `你选择了: ${picked}`),
        pills.map((pill) =>
          m(
            ".",
            m("input", {
              id: pill,
              checked: picked == pill,
              type: "radio",
              value: pill,
              onchange: handleChange,
            }),
            m("label", { for: pill }, pill),
          ),
        ),
      ),
  };
}

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 },
  ];
}

Mithril 标志 Mithril

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

export default function ColorSelect() {
  let selectedColorId = 2;

  const handleSelect = ({ target: { value } }) => (selectedColorId = value);

  return {
    view: () =>
      m(
        "select",
        { value: selectedColorId, onchange: handleSelect },
        colors.map(({ id, text, isDisabled }) =>
          m("option", { key: id, id, disabled: isDisabled, value: id }, text),
        ),
      ),
  };
}

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>

Mithril 标志 Mithril

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./main.jsx"></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;
  };
}

Mithril 标志 Mithril

import m from "mithril";

export default function App() {
  let isLoading = false;
  let error = null;
  let users = [];

  async function fetchUsers() {
    isLoading = true;
    try {
      const { results } = await m.request(
        "https://randomuser.me/api/?results=3",
      );
      users = results;
    } catch (err) {
      error = err;
    }
    isLoading = false;
  }

  return {
    oninit: fetchUsers,
    view() {
      if (isLoading) return m("p", "正在获取用户信息……");
      if (error) return m("p", "获取用户信息出错");
      return users.map((user) =>
        m(
          "li",
          { key: user.login.uuid },
          m("img", { src: user.picture.thumbnail, alt: "user" }),
          m("p", `${user.name.first} ${user.name.last}`),
        ),
      );
    },
  };
}