SvelteRuntime

Imperative component API

每个 Svelte 应用程序都通过强制创建根组件开始。在客户端，此组件被挂载到特定元素上。在服务器上，你希望得到一个 HTML 字符串，你可以用它进行渲染。以下函数可以帮助你完成这些任务。

挂载

实例化一个组件并将其挂载到指定的目标：

import { function mount<Props extends Record<string, any>, Exports extends Record<string, any>>(component: ComponentType<SvelteComponent<Props>> | Component<Props, Exports, any>, options: MountOptions<Props>): ExportsMounts a component to the given target and returns the exports and potentially the props (if compiled with accessors: true) of the component.
Transitions will play during the initial render unless the intro option is set to false.
mount } from 'svelte';
import type App = SvelteComponent<Record<string, any>, any, any>
const App: LegacyComponentTypeApp from './App.svelte';

const const app: {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<string, any>app = mount<Record<string, any>, {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<...>>(component: ComponentType<...> | Component<...>, options: MountOptions<...>): {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<...>Mounts a component to the given target and returns the exports and potentially the props (if compiled with accessors: true) of the component.
Transitions will play during the initial render unless the intro option is set to false.
mount(const App: LegacyComponentTypeApp, {
	target: Document | Element | ShadowRootTarget element where the component will be mounted.
target: var document: DocumentMDN Reference
document.ParentNode.querySelector<Element>(selectors: string): Element | null (+4 overloads)Returns the first element that is a descendant of node that matches selectors.
MDN Reference
querySelector('#app'),
	props?: Record<string, any> | undefinedComponent properties.
props: { some: stringsome: 'property' }
});

您可以在每页上挂载多个组件，也可以在您的应用程序内部挂载，例如在创建工具提示组件并将其附加到悬停元素时。

请注意，与在 Svelte 4 中调用 new App(...) 不同，在 mount 期间，像效果（包括 onMount 回调和操作函数）这样的操作将不会运行。如果您需要强制挂起的操作运行（例如在测试的上下文中），可以使用 flushSync() 来实现。

卸载

卸载之前使用 mount 或 hydrate 创建的组件。

如果 options.outro 是 true，则在组件从 DOM 中移除之前，将播放 transitions。

import { function mount<Props extends Record<string, any>, Exports extends Record<string, any>>(component: ComponentType<SvelteComponent<Props>> | Component<Props, Exports, any>, options: MountOptions<Props>): ExportsMounts a component to the given target and returns the exports and potentially the props (if compiled with accessors: true) of the component.
Transitions will play during the initial render unless the intro option is set to false.
mount, function unmount(component: Record<string, any>, options?: {
    outro?: boolean;
} | undefined): Promise<void>Unmounts a component that was previously mounted using mount or hydrate.
Since 5.13.0, if options.outro is true, transitions will play before the component is removed from the DOM.
Returns a Promise that resolves after transitions have completed if options.outro is true, or immediately otherwise (prior to 5.13.0, returns void).
import { mount, unmount } from 'svelte';
import App from './App.svelte';

const app = mount(App, { target: document.body });

// later...
unmount(app, { outro: true });unmount } from 'svelte';
import type App = SvelteComponent<Record<string, any>, any, any>
const App: LegacyComponentTypeApp from './App.svelte';

const const app: {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<string, any>app = mount<Record<string, any>, {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<...>>(component: ComponentType<...> | Component<...>, options: MountOptions<...>): {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<...>Mounts a component to the given target and returns the exports and potentially the props (if compiled with accessors: true) of the component.
Transitions will play during the initial render unless the intro option is set to false.
mount(const App: LegacyComponentTypeApp, { target: Document | Element | ShadowRootTarget element where the component will be mounted.
target: var document: DocumentMDN Reference
document.Document.body: HTMLElementSpecifies the beginning and end of the document body.
MDN Reference
body });

// later
function unmount(component: Record<string, any>, options?: {
    outro?: boolean;
} | undefined): Promise<void>Unmounts a component that was previously mounted using mount or hydrate.
Since 5.13.0, if options.outro is true, transitions will play before the component is removed from the DOM.
Returns a Promise that resolves after transitions have completed if options.outro is true, or immediately otherwise (prior to 5.13.0, returns void).
import { mount, unmount } from 'svelte';
import App from './App.svelte';

const app = mount(App, { target: document.body });

// later...
unmount(app, { outro: true });unmount(const app: {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<string, any>app, { outro?: boolean | undefinedoutro: true });

返回一个在过渡完成后解决的 Promise，如果 options.outro 为 true，否则立即解决。

渲染

仅适用于服务器上，并在使用服务器选项编译时可用。接受一个组件并返回一个具有和属性的body和head属性的对象，您可以使用它来在服务器端渲染您的应用程序时填充 HTML：

import { function render<Comp extends SvelteComponent<any> | Component<any>, Props extends ComponentProps<Comp> = ComponentProps<Comp>>(...args: {} extends Props ? [component: Comp extends SvelteComponent<any> ? ComponentType<Comp> : Comp, options?: {
    props?: Omit<Props, "$$slots" | "$$events">;
    context?: Map<any, any>;
    idPrefix?: string;
}] : [component: Comp extends SvelteComponent<any> ? ComponentType<Comp> : Comp, options: {
    props: Omit<Props, "$$slots" | "$$events">;
    context?: Map<any, any>;
    idPrefix?: string;
}]): RenderOutputOnly available on the server and when compiling with the server option.
Takes a component and returns an object with body and head properties on it, which you can use to populate the HTML when server-rendering your app.
render } from 'svelte/server';
import type App = SvelteComponent<Record<string, any>, any, any>
const App: LegacyComponentTypeApp from './App.svelte';

const const result: RenderOutputresult = render<SvelteComponent<Record<string, any>, any, any>, Record<string, any>>(component: ComponentType<SvelteComponent<Record<string, any>, any, any>>, options?: {
    ...;
} | undefined): RenderOutputOnly available on the server and when compiling with the server option.
Takes a component and returns an object with body and head properties on it, which you can use to populate the HTML when server-rendering your app.
render(const App: LegacyComponentTypeApp, {
	props?: Omit<Record<string, any>, "$$slots" | "$$events"> | undefinedprops: { some: stringsome: 'property' }
});
const result: RenderOutputresult.RenderOutput.body: stringHTML that goes somewhere into the &#x3C;body>
body; // HTML for somewhere in this <body> tag
const result: RenderOutputresult.RenderOutput.head: stringHTML that goes into the &#x3C;head>
head; // HTML for somewhere in this <head> tag

水合

与mount类似，但会重用 Svelte 的 SSR 输出（来自render函数）中在目标内的任何 HTML 渲染，使其变为交互式：

import { function hydrate<Props extends Record<string, any>, Exports extends Record<string, any>>(component: ComponentType<SvelteComponent<Props>> | Component<Props, Exports, any>, options: {} extends Props ? {
    target: Document | Element | ShadowRoot;
    props?: Props;
    events?: Record<string, (e: any) => any>;
    context?: Map<any, any>;
    intro?: boolean;
    recover?: boolean;
} : {
    target: Document | Element | ShadowRoot;
    props: Props;
    events?: Record<string, (e: any) => any>;
    context?: Map<any, any>;
    intro?: boolean;
    recover?: boolean;
}): ExportsHydrates a component on the given target and returns the exports and potentially the props (if compiled with accessors: true) of the component
hydrate } from 'svelte';
import type App = SvelteComponent<Record<string, any>, any, any>
const App: LegacyComponentTypeApp from './App.svelte';

const const app: {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<string, any>app = hydrate<Record<string, any>, {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<...>>(component: ComponentType<...> | Component<...>, options: {
    ...;
}): {
    $on?(type: string, callback: (e: any) => void): () => void;
    $set?(props: Partial<Record<string, any>>): void;
} & Record<...>Hydrates a component on the given target and returns the exports and potentially the props (if compiled with accessors: true) of the component
hydrate(const App: LegacyComponentTypeApp, {
	target: Document | Element | ShadowRoottarget: var document: DocumentMDN Reference
document.ParentNode.querySelector<Element>(selectors: string): Element | null (+4 overloads)Returns the first element that is a descendant of node that matches selectors.
MDN Reference
querySelector('#app'),
	props?: Record<string, any> | undefinedprops: { some: stringsome: 'property' }
});

与mount一样，在hydrate期间不会运行效果 — 如果需要，请立即使用flushSync()。

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