solidjs

SolidJS 开发

SolidJS 是一个声明式 JavaScript 库，用于构建具有细粒度响应性的用户界面。与虚拟 DOM 框架不同，Solid 会将模板编译为真实 DOM 节点，并通过细粒度响应机制更新它们。

核心原则

1. 组件只运行一次 — 组件函数仅在初始化期间执行，不会在每次更新时执行
2. 细粒度响应性 — 只有依赖已更改数据的特定 DOM 节点会更新
3. 没有虚拟 DOM — 通过编译后的模板直接操作 DOM
4. 信号是函数 — 通过调用获取值：count() 而不是 count

响应式原语

信号 — 基本状态

import { createSignal } from "solid-js";

const [count, setCount] = createSignal(0);

// Read value (getter)
console.log(count()); // 0

// Update value (setter)
setCount(1);
setCount(prev => prev + 1); // Functional update

选项：

const [value, setValue] = createSignal(initialValue, {
  equals: false, // Always trigger updates, even if value unchanged
  name: "debugName" // For devtools
});

Effects — 副作用

import { createEffect } from "solid-js";

createEffect(() => {
  console.log("Count changed:", count());
  // Runs after render, re-runs when dependencies change
});

主要行为：

• 首次运行：渲染后、浏览器绘制前
• 后续运行：跟踪的依赖项发生变化时
• SSR 或 hydration 期间不会运行
• 使用 onCleanup 执行清理逻辑

Memos — 派生／缓存值

import { createMemo } from "solid-js";

const doubled = createMemo(() => count() * 2);

// Access like signal
console.log(doubled()); // Cached, only recalculates when count changes

在以下情况使用 memos：

• 派生值的计算开销较大
• 派生值会被多次访问
• 希望在结果未改变时阻止下游更新

Resources — 异步数据

import { createResource } from "solid-js";

const [user, { mutate, refetch }] = createResource(userId, fetchUser);

// In JSX
<Show when={!user.loading} fallback={<Loading />}>
  <div>{user()?.name}</div>
</Show>

// Resource properties
user.loading   // boolean
user.error     // error if failed
user.state     // "unresolved" | "pending" | "ready" | "refreshing" | "errored"
user.latest    // last successful value

Stores — 复杂状态

用于需要细粒度更新的嵌套对象／数组：

import { createStore } from "solid-js/store";

const [state, setState] = createStore({
  user: { name: "John", age: 30 },
  todos: []
});

// Path syntax updates
setState("user", "name", "Jane");
setState("todos", todos => [...todos, newTodo]);
setState("todos", 0, "completed", true);

// Produce for immer-like updates
import { produce } from "solid-js/store";
setState(produce(s => {
  s.user.age++;
  s.todos.push(newTodo);
}));

Store 工具：

• produce — 类似 Immer 的变更操作
• reconcile — 对数据进行差异比较和修补（用于 API 响应）
• unwrap — 获取原始的非响应式对象

组件

基本组件

import { Component } from "solid-js";

const MyComponent: Component<{ name: string }> = (props) => {
  return <div>Hello, {props.name}</div>;
};

Props 处理

import { splitProps, mergeProps } from "solid-js";

// Default props
const merged = mergeProps({ size: "medium" }, props);

// Split props (for spreading)
const [local, others] = splitProps(props, ["class", "onClick"]);
return <button class={local.class} {...others} />;

Props 规则：

• Props 是响应式 getter — 不要在顶层解构
• 在 JSX 中使用 props.value，而不是 const { value } = props

Children 辅助函数

import { children } from "solid-js";

const Wrapper: Component = (props) => {
  const resolved = children(() => props.children);
  
  createEffect(() => {
    console.log("Children:", resolved());
  });
  
  return <div>{resolved()}</div>;
};

控制流组件

Show — 条件渲染

import { Show } from "solid-js";

<Show when={user()} fallback={<Login />}>
  {(user) => <Profile user={user()} />}
</Show>

For — 列表渲染（按引用键控）

import { For } from "solid-js";

<For each={items()} fallback={<Empty />}>
  {(item, index) => (
    <div>{index()}: {item.name}</div>
  )}
</For>

注意： index 是信号，item 是值。

Index — 列表渲染（按索引键控）

import { Index } from "solid-js";

<Index each={items()}>
  {(item, index) => (
    <input value={item().text} />
  )}
</Index>

注意： item 是信号，index 是值。更适合原始值数组或输入框。

Switch/Match — 多条件判断

import { Switch, Match } from "solid-js";

<Switch fallback={<Default />}>
  <Match when={state() === "loading"}>
    <Loading />
  </Match>
  <Match when={state() === "error"}>
    <Error />
  </Match>
  <Match when={state() === "success"}>
    <Success />
  </Match>
</Switch>

Dynamic — 动态组件

import { Dynamic } from "solid-js/web";

<Dynamic component={selected()} someProp="value" />

Portal — 在 DOM 层级之外渲染

import { Portal } from "solid-js/web";

<Portal mount={document.body}>
  <Modal />
</Portal>

ErrorBoundary — 错误处理

import { ErrorBoundary } from "solid-js";

<ErrorBoundary fallback={(err, reset) => (
  <div>
    Error: {err.message}
    <button onClick={reset}>Retry</button>
  </div>
)}>
  <RiskyComponent />
</ErrorBoundary>

Suspense — 异步加载

import { Suspense } from "solid-js";

<Suspense fallback={<Loading />}>
  <AsyncComponent />
</Suspense>

Context API

import { createContext, useContext } from "solid-js";

// Create context
const CounterContext = createContext<{
  count: () => number;
  increment: () => void;
}>();

// Provider component
export function CounterProvider(props) {
  const [count, setCount] = createSignal(0);
  
  return (
    <CounterContext.Provider value={{
      count,
      increment: () => setCount(c => c + 1)
    }}>
      {props.children}
    </CounterContext.Provider>
  );
}

// Consumer hook
export function useCounter() {
  const ctx = useContext(CounterContext);
  if (!ctx) throw new Error("useCounter must be used within CounterProvider");
  return ctx;
}

生命周期

import { onMount, onCleanup } from "solid-js";

function MyComponent() {
  onMount(() => {
    console.log("Mounted");
    const handler = () => {};
    window.addEventListener("resize", handler);
    
    onCleanup(() => {
      window.removeEventListener("resize", handler);
    });
  });
  
  return <div>Content</div>;
}

Refs

let inputRef: HTMLInputElement;

<input ref={inputRef} />
<input ref={(el) => { /* el is the DOM element */ }} />

事件处理

// Standard events (lowercase)
<button onClick={handleClick}>Click</button>
<button onClick={(e) => handleClick(e)}>Click</button>

// Delegated events (on:)
<input on:input={handleInput} />

// Native events (on:) - not delegated
<div on:scroll={handleScroll} />

路由（Solid Router）

完整路由指南请参阅 references/routing.md。

快速设置：

import { Router, Route } from "@solidjs/router";

<Router>
  <Route path="/" component={Home} />
  <Route path="/users/:id" component={User} />
  <Route path="*404" component={NotFound} />
</Router>

SolidStart

全栈开发指南请参阅 references/solidstart.md。

快速设置：

npm create solid@latest my-app
cd my-app && npm install && npm run dev

常见模式

条件类名

import { clsx } from "clsx"; // or classList

<div class={clsx("base", { active: isActive() })} />
<div classList={{ active: isActive(), disabled: isDisabled() }} />

批量更新

import { batch } from "solid-js";

batch(() => {
  setName("John");
  setAge(30);
  // Effects run once after batch completes
});

Untrack

import { untrack } from "solid-js";

createEffect(() => {
  console.log(count()); // tracked
  console.log(untrack(() => other())); // not tracked
});

TypeScript

import type { Component, ParentComponent, JSX } from "solid-js";

// Basic component
const Button: Component<{ label: string }> = (props) => (
  <button>{props.label}</button>
);

// With children
const Layout: ParentComponent<{ title: string }> = (props) => (
  <div>
    <h1>{props.title}</h1>
    {props.children}
  </div>
);

// Event handler types
const handleClick: JSX.EventHandler<HTMLButtonElement, MouseEvent> = (e) => {
  console.log(e.currentTarget);
};

项目设置

# Create new project
npm create solid@latest my-app

# With template
npx degit solidjs/templates/ts my-app

# SolidStart
npm create solid@latest my-app -- --template solidstart

vite.config.ts：

import { defineConfig } from "vite";
import solid from "vite-plugin-solid";

export default defineConfig({
  plugins: [solid()]
});

应避免的反模式

1. 解构 props — 会破坏响应性

   // ❌ Bad
   const { name } = props;
   
   // ✅ Good
   props.name
   

2. 在跟踪范围之外访问信号

   // ❌ Won't update
   console.log(count());
   
   // ✅ Will update
   createEffect(() => console.log(count()));
   

3. 忘记调用信号 getter

   // ❌ Passes the function
   <div>{count}</div>
   
   // ✅ Passes the value
   <div>{count()}</div>
   

4. 使用数组索引作为键 — 引用键控使用 <For>，索引键控使用 <Index>

5. 在渲染期间执行副作用 — 使用 createEffect 或 onMount