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SvelteKit附录

从 Sapper 迁移

SvelteKit 是 Sapper 的后继者，并共享其设计的许多元素。

¥SvelteKit is the successor to Sapper and shares many elements of its design.

如果你有一个现有的 Sapper 应用并计划将其迁移到 SvelteKit，则需要进行一些更改。你可能会发现在迁移时查看 一些示例 很有帮助。

¥If you have an existing Sapper app that you plan to migrate to SvelteKit, there are a number of changes you will need to make. You may find it helpful to view some examples while migrating.

package.json

type:”module”(type: “module”)

将 "type": "module" 添加到你的 package.json。如果你使用的是 Sapper 0.29.3 或更新版本，则可以将此步骤与其余步骤分开执行，作为增量迁移的一部分。

¥Add "type": "module" to your package.json. You can do this step separately from the rest as part of an incremental migration if you are using Sapper 0.29.3 or newer.

dependencies

如果你正在使用其中之一，请删除 polka 或 express，以及任何中间件，例如 sirv 或 compression。

¥Remove polka or express, if you’re using one of those, and any middleware such as sirv or compression.

devDependencies

从你的 devDependencies 中删除 sapper，并将其替换为 @sveltejs/kit 和你计划使用的任何 adapter（参见 下一节）。

¥Remove sapper from your devDependencies and replace it with @sveltejs/kit and whichever adapter you plan to use (see next section).

scripts

任何引用 sapper 的脚本都应更新：

¥Any scripts that reference sapper should be updated:

  • sapper build 应该使用 Node adapter 变为 vite build

    ¥sapper build should become vite build using the Node adapter

  • sapper export 应该使用静态 adapter 变为 vite build

    ¥sapper export should become vite build using the static adapter

  • sapper dev 应该变成 vite dev

    ¥sapper dev should become vite dev

  • node __sapper__/build 应该变成 node build

    ¥node __sapper__/build should become node build

项目文件(Project files)

¥Project files

在 src/routes 中，你的应用的大部分内容可以保留在原处，但需要移动或更新几个项目文件。

¥The bulk of your app, in src/routes, can be left where it is, but several project files will need to be moved or updated.

配置(Configuration)

¥Configuration

你的 webpack.config.js 或 rollup.config.js 应该替换为 svelte.config.js，如 此处 所述。Svelte 预处理器选项应移至 config.preprocess。

¥Your webpack.config.js or rollup.config.js should be replaced with a svelte.config.js, as documented here. Svelte preprocessor options should be moved to config.preprocess.

你需要添加 adapter。sapper build 大致相当于 adapter-node，而 sapper export 大致相当于 adapter-static，但你可能更喜欢使用为要部署到的平台设计的适配器。

¥You will need to add an adapter. sapper build is roughly equivalent to adapter-node while sapper export is roughly equivalent to adapter-static, though you might prefer to use an adapter designed for the platform you’re deploying to.

如果你使用的文件类型插件无法由 Vite 自动处理，则需要找到 Vite 等效插件并将其添加到 Vite 配置。

¥If you were using plugins for filetypes that are not automatically handled by Vite, you will need to find Vite equivalents and add them to the Vite config.

src/client.js

此文件在 SvelteKit 中没有等效项。任何自定义逻辑（超出 sapper.start(...)）都应在 +layout.svelte 文件中的 onMount 回调内表达。

¥This file has no equivalent in SvelteKit. Any custom logic (beyond sapper.start(...)) should be expressed in your +layout.svelte file, inside an onMount callback.

src/server.js

使用 adapter-node 时，等效处理程序为 自定义服务器。否则，此文件没有直接等效项，因为 SvelteKit 应用可以在无服务器环境中运行。

¥When using adapter-node the equivalent is a custom server. Otherwise, this file has no direct equivalent, since SvelteKit apps can run in serverless environments.

src/service-worker.js

大多数从 @sapper/service-worker 导入的内容在 $service-worker 中都有等效项：

¥Most imports from @sapper/service-worker have equivalents in $service-worker:

  • files 未更改

    ¥files is unchanged

  • routes 已被移除

    ¥routes has been removed

  • shell 现在是 build

    ¥shell is now build

  • timestamp 现在是 version

    ¥timestamp is now version

src/template.html

src/template.html 文件应重命名为 src/app.html。

¥The src/template.html file should be renamed src/app.html.

删除 %sapper.base%、%sapper.scripts% 和 %sapper.styles%。将 %sapper.head% 替换为 %sveltekit.head%，将 %sapper.html% 替换为 %sveltekit.body%。<div id="sapper"> 不再是必需的。

¥Remove %sapper.base%, %sapper.scripts% and %sapper.styles%. Replace %sapper.head% with %sveltekit.head% and %sapper.html% with %sveltekit.body%. The <div id="sapper"> is no longer necessary.

src/node_modules

Sapper 应用中的常见模式是将内部库放在 src/node_modules 内的目录中。这不适用于 Vite，因此我们改用 src/lib。

¥A common pattern in Sapper apps is to put your internal library in a directory inside src/node_modules. This doesn’t work with Vite, so we use src/lib instead.

页面和布局(Pages and layouts)

¥Pages and layouts

重命名文件(Renamed files)

¥Renamed files

为了消除歧义，现在的路由仅由文件夹名称组成，文件夹名称指向 +page.svelte 对应于路由。有关概述，请参阅 路由文档。以下显示了旧/新比较：

¥Routes now are made up of the folder name exclusively to remove ambiguity, the folder names leading up to a +page.svelte correspond to the route. See the routing docs for an overview. The following shows a old/new comparison:

旧 新
routes/about/index.svelte 行类型
routes/about.svelte 行类型

你的自定义错误页面组件应从 _error.svelte 重命名为 +error.svelte。任何 _layout.svelte 都作为 DOM 元素的属性公开（以及在可能的情况下作为属性可读/可写）。忽略任何其他文件。

¥Your custom error page component should be renamed from _error.svelte to +error.svelte. Any _layout.svelte files should likewise be renamed +layout.svelte. Any other files are ignored.

导入(Imports)

¥Imports

来自 @sapper/app 的 goto、prefetch 和 prefetchRoutes 导入应分别替换为来自 $app/navigation 的 goto、preloadData 和 preloadCode 导入。

¥The goto, prefetch and prefetchRoutes imports from @sapper/app should be replaced with goto, preloadData and preloadCode imports respectively from $app/navigation.

应替换从 @sapper/app 导入的 stores — 请参阅下面的 存储 部分。

¥The stores import from @sapper/app should be replaced — see the Stores section below.

你之前从 src/node_modules 目录中导入的任何文件都需要用 $lib 导入替换。

¥Any files you previously imported from directories in src/node_modules will need to be replaced with $lib imports.

预加载(Preload)

¥Preload

与以前一样，页面和布局可以导出一个函数，允许在渲染之前加载数据。

¥As before, pages and layouts can export a function that allows data to be loaded before rendering takes place.

此函数已从 preload 重命名为 load，它现在位于其 +page.svelte（或 +layout.svelte）旁边的 +page.js（或 +layout.js）中，并且其 API 已更改。不再有两个参数 — page 和 session — 而是一个 event 参数。

¥This function has been renamed from preload to load, it now lives in a +page.js (or +layout.js) next to its +page.svelte (or +layout.svelte), and its API has changed. Instead of two arguments — page and session — there is a single event argument.

不再有 this 对象，因此也没有 this.fetch、this.error 或 this.redirect。相反，你可以从输入法中获取 fetch，现在会抛出 error 和 redirect。

¥There is no more this object, and consequently no this.fetch, this.error or this.redirect. Instead, you can get fetch from the input methods, and both error and redirect are now thrown.

存储(Stores)

¥Stores

在 Sapper 中，你将获得对提供的存储的引用，如下所示：

¥In Sapper, you would get references to provided stores like so:

import { module "@sapper/app"stores } from '@sapper/app';
const { const preloading: anypreloading, const page: anypage, const session: anysession } = module "@sapper/app"stores();

page 存储仍然存在；preloading 已被替换为包含 from 和 to 属性的 navigating 存储。page 现在具有 url 和 params 属性，但没有 path 或 query。

¥The page store still exists; preloading has been replaced with a navigating store that contains from and to properties. page now has url and params properties, but no path or query.

你可以在 SvelteKit 中以不同的方式访问它们。stores 现在是 getStores，但在大多数情况下这是不必要的，因为你可以直接从 $app/stores 导入 navigating 和 page。如果你使用的是 Svelte 5 和 SvelteKit 2.12 或更高版本，请考虑改用 $app/state。

¥You access them differently in SvelteKit. stores is now getStores, but in most cases it is unnecessary since you can import navigating, and page directly from $app/stores. If you’re on Svelte 5 and SvelteKit 2.12 or higher, consider using $app/state instead.

路由(Routing)

¥Routing

不再支持正则表达式路由。而是使用 高级路由匹配。

¥Regex routes are no longer supported. Instead, use advanced route matching.

片段(Segments)

¥Segments

以前，布局组件收到一个指示子段的 segment prop。这已被删除；你应该使用更灵活的 $page.url.pathname（或 page.url.pathname）值来派生你感兴趣的段。

¥Previously, layout components received a segment prop indicating the child segment. This has been removed; you should use the more flexible $page.url.pathname (or page.url.pathname) value to derive the segment you’re interested in.

URLs

在 Sapper 中，所有相对 URL 都是针对基本 URL（通常是 /，除非使用了 basepath 选项）而不是针对当前页面进行解析的。

¥In Sapper, all relative URLs were resolved against the base URL — usually /, unless the basepath option was used — rather than against the current page.

这会导致问题，但在 SvelteKit 中不再如此。相反，相对 URL 是根据当前页面（或 load 函数中的 fetch URL 的目标页面）解析的。在大多数情况下，使用根相对（即以 / 开头）URL 更容易，因为它们的含义不依赖于上下文。

¥This caused problems and is no longer the case in SvelteKit. Instead, relative URLs are resolved against the current page (or the destination page, for fetch URLs in load functions) instead. In most cases, it’s easier to use root-relative (i.e. starts with /) URLs, since their meaning is not context-dependent.

<a>属性(&lt;a> attributes)

¥&lt;a> attributes

  • sapper:prefetch 现在是 data-sveltekit-preload-data

    ¥sapper:prefetch is now data-sveltekit-preload-data

  • sapper:noscroll 现在是 data-sveltekit-noscroll

    ¥sapper:noscroll is now data-sveltekit-noscroll

端点(Endpoints)

¥Endpoints

在 Sapper 中，服务器路由 接收 Node 的 http 模块（或 Polka 和 Express 等框架提供的增强版本）公开的 req 和 res 对象。

¥In Sapper, server routes received the req and res objects exposed by Node’s http module (or the augmented versions provided by frameworks like Polka and Express).

SvelteKit 的设计与应用的运行位置无关 - 它可以运行在 Node 服务器上，但也可以运行在无服务器平台或 Cloudflare Worker 中。因此，你不再直接与 req 和 res 交互。你的端点需要更新以匹配新签名。

¥SvelteKit is designed to be agnostic as to where the app is running — it could be running on a Node server, but could equally be running on a serverless platform or in a Cloudflare Worker. For that reason, you no longer interact directly with req and res. Your endpoints will need to be updated to match the new signature.

为了支持这种与环境无关的行为，fetch 现在在全局上下文中可用，因此你无需导入 node-fetch、cross-fetch 或类似的服务器端获取实现即可使用它。

¥To support this environment-agnostic behavior, fetch is now available in the global context, so you don’t need to import node-fetch, cross-fetch, or similar server-side fetch implementations in order to use it.

集成(Integrations)

¥Integrations

有关集成的详细信息，请参阅 integrations。

¥See integrations for detailed information about integrations.

HTML 压缩器(HTML minifier)

¥HTML minifier

Sapper 默认包含 html-minifier。SvelteKit 不包含此功能，但你可以将其添加为 prod 依赖，然后通过 hook 使用它：

¥Sapper includes html-minifier by default. SvelteKit does not include this, but you can add it as a prod dependency and then use it through a hook:

import { module "html-minifier"minify } from 'html-minifier';
import { const building: boolean
SvelteKit analyses your app during the build step by running it. During this process, building is true. This also applies during prerendering.


building } from '$app/environment';

const 
const minification_options: {
    collapseBooleanAttributes: boolean;
    collapseWhitespace: boolean;
    conservativeCollapse: boolean;
    decodeEntities: boolean;
    html5: boolean;
    ignoreCustomComments: RegExp[];
    minifyCSS: boolean;
    ... 8 more ...;
    sortClassName: boolean;
}
minification_options = {
	collapseBooleanAttributes: booleancollapseBooleanAttributes: true,
	collapseWhitespace: booleancollapseWhitespace: true,
	conservativeCollapse: booleanconservativeCollapse: true,
	decodeEntities: booleandecodeEntities: true,
	html5: booleanhtml5: true,
	ignoreCustomComments: RegExp[]ignoreCustomComments: [/^#/],
	minifyCSS: booleanminifyCSS: true,
	minifyJS: booleanminifyJS: false,
	removeAttributeQuotes: booleanremoveAttributeQuotes: true,
	removeComments: booleanremoveComments: false, // some hydration code needs comments, so leave them in
	removeOptionalTags: booleanremoveOptionalTags: true,
	removeRedundantAttributes: booleanremoveRedundantAttributes: true,
	removeScriptTypeAttributes: booleanremoveScriptTypeAttributes: true,
	removeStyleLinkTypeAttributes: booleanremoveStyleLinkTypeAttributes: true,
	sortAttributes: booleansortAttributes: true,
	sortClassName: booleansortClassName: true
};

/** @type {import('@sveltejs/kit').Handle} */
export async function 
function handle(input: {
    event: RequestEvent;
    resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>;
}): MaybePromise<...>
@type{import('@sveltejs/kit').Handle}
handle({ event: RequestEvent<Partial<Record<string, string>>, string | null>event, resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>resolve }) {
	let let page: stringpage = '';

	return resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>resolve(event: RequestEvent<Partial<Record<string, string>>, string | null>event, {
		
ResolveOptions.transformPageChunk?: ((input: {
    html: string;
    done: boolean;
}) => MaybePromise<string | undefined>) | undefined
Applies custom transforms to HTML. If done is true, it’s the final chunk. Chunks are not guaranteed to be well-formed HTML
(they could include an element’s opening tag but not its closing tag, for example)
but they will always be split at sensible boundaries such as %sveltekit.head% or layout/page components.


@paraminput the html chunk and the info if this is the last chunk
transformPageChunk: ({ html: stringhtml, done: booleandone }) => {
			let page: stringpage += html: stringhtml;
			if (done: booleandone) {
				return const building: boolean
SvelteKit analyses your app during the build step by running it. During this process, building is true. This also applies during prerendering.


building ? module "html-minifier"minify(let page: stringpage, 
const minification_options: {
    collapseBooleanAttributes: boolean;
    collapseWhitespace: boolean;
    conservativeCollapse: boolean;
    decodeEntities: boolean;
    html5: boolean;
    ignoreCustomComments: RegExp[];
    minifyCSS: boolean;
    ... 8 more ...;
    sortClassName: boolean;
}
minification_options) : let page: stringpage;
			}
		}
	});
}

请注意，使用 vite preview 测试站点的生产版本时，prerendering 是 false，因此要验证最小化的结果，你需要直接检查构建的 HTML 文件。

¥Note that prerendering is false when using vite preview to test the production build of the site, so to verify the results of minifying, you’ll need to inspect the built HTML files directly.

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