@sveltejs/kit/hooks

import {
	function defineEnvVars<T extends Record<string, EnvVarConfig<any>>>(variables: T): T
Utility for defining environment variables,
which are made available via $app/env/public and $app/env/private.
@deprecatedImport `defineEnvVars` from `@sveltejs/kit/env` insteadfunction defineEnvVars<T extends Record<string, EnvVarConfig<any>>>(variables: T): T
Utility for defining environment variables,
which are made available via $app/env/public and $app/env/private.
@deprecatedImport `defineEnvVars` from `@sveltejs/kit/env` insteaddefineEnvVars,
	function sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner.
The behavior for the handle options is as follows:
transformPageChunk is applied in reverse order and merged
preload is applied in forward order, the first option "wins" and no preload options after it are called
filterSerializedResponseHeaders behaves the same as preload
/// file: src/hooks.server.js
import { sequence } from '@sveltejs/kit/hooks';

/// type: import('@sveltejs/kit').Handle
async function first({ event, resolve }) {
	console.log('first pre-processing');
	const result = await resolve(event, {
		transformPageChunk: ({ html }) => {
			// transforms are applied in reverse order
			console.log('first transform');
			return html;
		},
		preload: () => {
			// this one wins as it's the first defined in the chain
			console.log('first preload');
			return true;
		}
	});
	console.log('first post-processing');
	return result;
}

/// type: import('@sveltejs/kit').Handle
async function second({ event, resolve }) {
	console.log('second pre-processing');
	const result = await resolve(event, {
		transformPageChunk: ({ html }) => {
			console.log('second transform');
			return html;
		},
		preload: () => {
			console.log('second preload');
			return true;
		},
		filterSerializedResponseHeaders: () => {
			// this one wins as it's the first defined in the chain
			console.log('second filterSerializedResponseHeaders');
			return true;
		}
	});
	console.log('second post-processing');
	return result;
}

export const handle = sequence(first, second);
The example above would print:
first pre-processing
first preload
second pre-processing
second filterSerializedResponseHeaders
second transform
first transform
second post-processing
first post-processing
@paramhandlers The chain of `handle` functionsfunction sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner.
The behavior for the handle options is as follows:
transformPageChunk is applied in reverse order and merged
preload is applied in forward order, the first option "wins" and no preload options after it are called
filterSerializedResponseHeaders behaves the same as preload
/// file: src/hooks.server.js
import { sequence } from '@sveltejs/kit/hooks';

/// type: import('@sveltejs/kit').Handle
async function first({ event, resolve }) {
	console.log('first pre-processing');
	const result = await resolve(event, {
		transformPageChunk: ({ html }) => {
			// transforms are applied in reverse order
			console.log('first transform');
			return html;
		},
		preload: () => {
			// this one wins as it's the first defined in the chain
			console.log('first preload');
			return true;
		}
	});
	console.log('first post-processing');
	return result;
}

/// type: import('@sveltejs/kit').Handle
async function second({ event, resolve }) {
	console.log('second pre-processing');
	const result = await resolve(event, {
		transformPageChunk: ({ html }) => {
			console.log('second transform');
			return html;
		},
		preload: () => {
			console.log('second preload');
			return true;
		},
		filterSerializedResponseHeaders: () => {
			// this one wins as it's the first defined in the chain
			console.log('second filterSerializedResponseHeaders');
			return true;
		}
	});
	console.log('second post-processing');
	return result;
}

export const handle = sequence(first, second);
The example above would print:
first pre-processing
first preload
second pre-processing
second filterSerializedResponseHeaders
second transform
first transform
second post-processing
first post-processing
@paramhandlers The chain of `handle` functionssequence
} from '@sveltejs/kit/hooks';

import { sequence } from '@sveltejs/kit/hooks';

/// type: import('@sveltejs/kit').Handle
async function first({ event, resolve }) {
	console.log('first pre-processing');
	const result = await resolve(event, {
		transformPageChunk: ({ html }) => {
			// transforms are applied in reverse order
			console.log('first transform');
			return html;
		},
		preload: () => {
			// this one wins as it's the first defined in the chain
			console.log('first preload');
			return true;
		}
	});
	console.log('first post-processing');
	return result;
}

/// type: import('@sveltejs/kit').Handle
async function second({ event, resolve }) {
	console.log('second pre-processing');
	const result = await resolve(event, {
		transformPageChunk: ({ html }) => {
			console.log('second transform');
			return html;
		},
		preload: () => {
			console.log('second preload');
			return true;
		},
		filterSerializedResponseHeaders: () => {
			// this one wins as it's the first defined in the chain
			console.log('second filterSerializedResponseHeaders');
			return true;
		}
	});
	console.log('second post-processing');
	return result;
}

export const handle = sequence(first, second);

first pre-processing
first preload
second pre-processing
second filterSerializedResponseHeaders
second transform
first transform
second post-processing
first post-processing