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.
```js
// @noErrors
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.
```dts
function asClassComponent<
Props extends Record
,
Exports extends Record,
Events extends Record,
Slots extends Record
>(
component:
| SvelteComponent
| Component
): ComponentType<
SvelteComponent & Exports
>;
```
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.
```dts
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.
```dts
function createClassComponent<
Props extends Record
,
Exports extends Record,
Events extends Record,
Slots extends Record
>(
options: ComponentConstructorOptions & {
component:
| ComponentType>
| Component;
}
): SvelteComponent & Exports;
```
```dts
function handlers(
...handlers: EventListener[]
): EventListener;
```
## nonpassive
Substitute for the `nonpassive` event modifier, implemented as an action
```dts
function nonpassive(
node: HTMLElement,
[event, handler]: [
event: string,
handler: () => EventListener
]
): void;
```
## once
Substitute for the `once` event modifier
```dts
function once(
fn: (event: Event, ...args: Array) => void
): (event: Event, ...args: unknown[]) => void;
```
## passive
Substitute for the `passive` event modifier, implemented as an action
```dts
function passive(
node: HTMLElement,
[event, handler]: [
event: string,
handler: () => EventListener
]
): void;
```
## preventDefault
Substitute for the `preventDefault` event modifier
```dts
function preventDefault(
fn: (event: Event, ...args: Array) => 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.
```dts
function run(fn: () => void | (() => void)): void;
```
## self
Substitute for the `self` event modifier
```dts
function self(
fn: (event: Event, ...args: Array) => void
): (event: Event, ...args: unknown[]) => void;
```
## stopImmediatePropagation
Substitute for the `stopImmediatePropagation` event modifier
```dts
function stopImmediatePropagation(
fn: (event: Event, ...args: Array) => void
): (event: Event, ...args: unknown[]) => void;
```
## stopPropagation
Substitute for the `stopPropagation` event modifier
```dts
function stopPropagation(
fn: (event: Event, ...args: Array) => void
): (event: Event, ...args: unknown[]) => void;
```
## trusted
Substitute for the `trusted` event modifier
```dts
function trusted(
fn: (event: Event, ...args: Array) => void
): (event: Event, ...args: unknown[]) => void;
```
## LegacyComponentType
Support using the component as both a class and function during the transition period
```dts
type LegacyComponentType = {
new (o: ComponentConstructorOptions): SvelteComponent;
(
...args: Parameters>>
): ReturnType<
Component, Record>
>;
};
```