svelte/legacy
This module provides various functions for use during the migration, since some features can’t be replaced one to one with new features. All imports are marked as deprecated and should be migrated away from over time.
import {
asClassComponent,
createBubbler,
createClassComponent,
handlers,
nonpassive,
once,
passive,
preventDefault,
run,
self,
stopImmediatePropagation,
stopPropagation,
trusted
} from 'svelte/legacy';asClassComponent
Use this only as a temporary solution to migrate your imperative component code to Svelte 5.
Takes the component function and returns a Svelte 4 compatible component constructor.
function asClassComponent<
Props extends Record<string, any>,
Exports extends Record<string, any>,
Events extends Record<string, any>,
Slots extends Record<string, any>
>(
component:
| SvelteComponent<Props, Events, Slots>
| Component<Props>
): ComponentType<
SvelteComponent<Props, Events, Slots> & Exports
>;createBubbler
Use this only as a temporary solution to migrate your automatically delegated events in Svelte 5.
Function to create a bubble function that mimic the behavior of on:click without handler available in svelte 4.
function createBubbler(): (
type: string
) => (event: Event) => boolean;createClassComponent
Use this only as a temporary solution to migrate your imperative component code to Svelte 5.
Takes the same options as a Svelte 4 component and the component function and returns a Svelte 4 compatible component.
function createClassComponent<
Props extends Record<string, any>,
Exports extends Record<string, any>,
Events extends Record<string, any>,
Slots extends Record<string, any>
>(
options: ComponentConstructorOptions<Props> & {
component:
| ComponentType<SvelteComponent<Props, Events, Slots>>
| Component<Props>;
}
): SvelteComponent<Props, Events, Slots> & Exports;handlers
Function to mimic the multiple listeners available in svelte 4
function handlers(
...handlers: EventListener[]
): EventListener;nonpassive
Substitute for the nonpassive event modifier, implemented as an action
function nonpassive(
node: HTMLElement,
[event, handler]: [
event: string,
handler: () => EventListener
]
): void;once
Substitute for the once event modifier
function once(
fn: (event: Event, ...args: Array<unknown>) => void
): (event: Event, ...args: unknown[]) => void;passive
Substitute for the passive event modifier, implemented as an action
function passive(
node: HTMLElement,
[event, handler]: [
event: string,
handler: () => EventListener
]
): void;preventDefault
Substitute for the preventDefault event modifier
function preventDefault(
fn: (event: Event, ...args: Array<unknown>) => void
): (event: Event, ...args: unknown[]) => void;run
Use this only as a temporary solution to migrate your component code to Svelte 5.
Runs the given function once immediately on the server, and works like $effect.pre on the client.
function run(fn: () => void | (() => void)): void;self
Substitute for the self event modifier
function self(
fn: (event: Event, ...args: Array<unknown>) => void
): (event: Event, ...args: unknown[]) => void;stopImmediatePropagation
Substitute for the stopImmediatePropagation event modifier
function stopImmediatePropagation(
fn: (event: Event, ...args: Array<unknown>) => void
): (event: Event, ...args: unknown[]) => void;stopPropagation
Substitute for the stopPropagation event modifier
function stopPropagation(
fn: (event: Event, ...args: Array<unknown>) => void
): (event: Event, ...args: unknown[]) => void;trusted
Substitute for the trusted event modifier
function trusted(
fn: (event: Event, ...args: Array<unknown>) => void
): (event: Event, ...args: unknown[]) => void;LegacyComponentType
Support using the component as both a class and function during the transition period
type LegacyComponentType = {
new (o: ComponentConstructorOptions): SvelteComponent;
(
...args: Parameters<Component<Record<string, any>>>
): ReturnType<
Component<Record<string, any>, Record<string, any>>
>;
};Edit this page on GitHub llms.txt