Component Party 标志

Component Party 中文版

响应式

声明状态

React 标志 React

import { useState } from "react";

export default function Name() {
  const [name] = useState("张三");

  return <h1>你好 {name}</h1>;
}

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

React 标志 React

import { useEffect, useState } from "react";

export default function Name() {
  const [name, setName] = useState("张三");

  useEffect(() => {
    setName("李四");
  }, []);

  return <h1>你好 {name}</h1>;
}

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

React 标志 React

import { useState } from "react";

export default function DoubleCount() {
  const [count] = useState(10);
  const doubleCount = count * 2;

  return <div>{doubleCount}</div>;
}

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

React 标志 React

export default function HelloWorld() {
  return <h1>你好，世界</h1>;
}

Ember Polaris 标志 Ember Polaris

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

样式

React 标志 React

import "./style.css";

export default function CssStyle() {
  return (
    <>
      <h1 className="title">我是红色的</h1>
      <button style={{ fontSize: "10rem" }}>我是一个按钮</button>
    </>
  );
}

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

React 标志 React

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

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

React 标志 React

import { useState } from "react";

export default function Counter() {
  const [count, setCount] = useState(0);

  function incrementCount() {
    setCount((count) => count + 1);
  }

  return (
    <>
      <p>计数器: {count}</p>
      <button onClick={incrementCount}>+1</button>
    </>
  );
}

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

React 标志 React

import { useEffect, useRef } from "react";

export default function InputFocused() {
  const inputElement = useRef(null);

  useEffect(() => inputElement.current.focus(), []);

  return <input type="text" ref={inputElement} />;
}

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

React 标志 React

import { useState } from "react";

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

export default function TrafficLight() {
  const [lightIndex, setLightIndex] = useState(0);

  const light = TRAFFIC_LIGHTS[lightIndex];

  function nextLight() {
    setLightIndex((lightIndex + 1) % TRAFFIC_LIGHTS.length);
  }

  return (
    <>
      <button onClick={nextLight}>下一个灯</button>
      <p>现在亮着的是: {light}</p>
      <p>
        你应该
        {light === "红灯" && <span>停下</span>}
        {light === "黄灯" && <span>慢行</span>}
        {light === "绿灯" && <span>赶紧走</span>}
      </p>
    </>
  );
}

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

React 标志 React

import { useState, useEffect } from "react";

export default function PageTitle() {
  const [pageTitle, setPageTitle] = useState("");

  useEffect(() => {
    setPageTitle(document.title);
  }, []);

  return <p>页面标题: {pageTitle}</p>;
}

Ember Polaris 标志 Ember Polaris

const pageTitle = () => document.title;

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

组件卸载时

React 标志 React

import { useState, useEffect } from "react";

export default function Time() {
  const [time, setTime] = useState(new Date().toLocaleTimeString());

  useEffect(() => {
    const timer = setInterval(() => {
      setTime(new Date().toLocaleTimeString());
    }, 1000);

    return () => clearInterval(timer);
  }, []);

  return <p>当前时间: {time}</p>;
}

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

React 标志 React

import UserProfile from "./UserProfile.jsx";

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

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

React 标志 React

import { useState } from "react";
import AnswerButton from "./AnswerButton.jsx";

export default function App() {
  const [isHappy, setIsHappy] = useState(true);

  function onAnswerNo() {
    setIsHappy(false);
  }

  function onAnswerYes() {
    setIsHappy(true);
  }

  return (
    <>
      <p>你快乐吗?</p>
      <AnswerButton onYes={onAnswerYes} onNo={onAnswerNo} />
      <p style={{ fontSize: 50 }}>{isHappy ? "😀" : "😥"}</p>
    </>
  );
}

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

React 标志 React

import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return <FunnyButton>点我!</FunnyButton>;
}

Ember Polaris 标志 Ember Polaris

import FunnyButton from "./funny-button";

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

slot插槽内容

React 标志 React

import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return (
    <>
      <FunnyButton />
      <FunnyButton>这是传到slot的内容!</FunnyButton>
    </>
  );
}

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

React 标志 React

import { useState } from "react";
import UserProfile from "./UserProfile";
import { UserContext } from "./UserContext";

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

  function updateUsername(newUsername) {
    setUser((userData) => ({ ...userData, username: newUsername }));
  }

  return (
    <>
      <h1>欢迎回来, {user.username}</h1>
      <UserContext.Provider value={{ ...user, updateUsername }}>
        <UserProfile />
      </UserContext.Provider>
    </>
  );
}

Ember Polaris 标志 Ember Polaris

import UserProfile from "./user-profile";

<template>
    <UserProfile />
</template>

表单输入

输入框

React 标志 React

import { useState } from "react";

export default function InputHello() {
  const [text, setText] = useState("你好世界");

  function handleChange(event) {
    setText(event.target.value);
  }

  return (
    <>
      <p>{text}</p>
      <input value={text} onChange={handleChange} />
    </>
  );
}

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

React 标志 React

import { useState } from "react";

export default function IsAvailable() {
  const [isAvailable, setIsAvailable] = useState(false);

  function handleChange() {
    setIsAvailable(!isAvailable);
  }

  return (
    <>
      <input
        id="is-available"
        type="checkbox"
        checked={isAvailable}
        onChange={handleChange}
      />
      <label htmlFor="is-available">这是一个checkbox</label>
    </>
  );
}

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

React 标志 React

import { useState } from "react";

export default function PickPill() {
  const [picked, setPicked] = useState("red");

  function handleChange(event) {
    setPicked(event.target.value);
  }

  return (
    <>
      <div>你选择了: {picked}</div>

      <input
        id="blue-pill"
        checked={picked === "blue"}
        type="radio"
        value="blue"
        onChange={handleChange}
      />
      <label htmlFor="blue-pill">蓝色</label>

      <input
        id="red-pill"
        checked={picked === "red"}
        type="radio"
        value="red"
        onChange={handleChange}
      />
      <label htmlFor="red-pill">红色</label>
    </>
  );
}

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

React 标志 React

import { useState } from "react";

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

export default function ColorSelect() {
  const [selectedColorId, setSelectedColorId] = useState(2);

  function handleChange(event) {
    setSelectedColorId(event.target.value);
  }

  return (
    <select value={selectedColorId} onChange={handleChange}>
      {colors.map((color) => (
        <option key={color.id} value={color.id} disabled={color.isDisabled}>
          {color.text}
        </option>
      ))}
    </select>
  );
}

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

React 标志 React

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

React 标志 React

import useFetchUsers from "./useFetchUsers";

export default function App() {
  const { isLoading, error, data: users } = useFetchUsers();

  return (
    <>
      {isLoading ? (
        <p>正在获取用户信息……</p>
      ) : error ? (
        <p>获取用户信息出错</p>
      ) : (
        users && (
          <ul>
            {users.map((user) => (
              <li key={user.login.uuid}>
                <img src={user.picture.thumbnail} alt="user" />
                <p>
                  {user.name.first} {user.name.last}
                </p>
              </li>
            ))}
          </ul>
        )
      )}
    </>
  );
}

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>
}