64 lines
2.6 KiB
TypeScript
64 lines
2.6 KiB
TypeScript
/**
|
|
* @license
|
|
* Copyright 2017 Google LLC
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*/
|
|
import { ChildPart, noChange } from '../lit-html.js';
|
|
import { Directive, PartInfo } from '../directive.js';
|
|
export type KeyFn<T> = (item: T, index: number) => unknown;
|
|
export type ItemTemplate<T> = (item: T, index: number) => unknown;
|
|
declare class RepeatDirective extends Directive {
|
|
private _itemKeys?;
|
|
constructor(partInfo: PartInfo);
|
|
private _getValuesAndKeys;
|
|
render<T>(items: Iterable<T>, template: ItemTemplate<T>): Array<unknown>;
|
|
render<T>(items: Iterable<T>, keyFn: KeyFn<T> | ItemTemplate<T>, template: ItemTemplate<T>): Array<unknown>;
|
|
update<T>(containerPart: ChildPart, [items, keyFnOrTemplate, template]: [
|
|
Iterable<T>,
|
|
KeyFn<T> | ItemTemplate<T>,
|
|
ItemTemplate<T>
|
|
]): unknown[] | typeof noChange;
|
|
}
|
|
export interface RepeatDirectiveFn {
|
|
<T>(items: Iterable<T>, keyFnOrTemplate: KeyFn<T> | ItemTemplate<T>, template?: ItemTemplate<T>): unknown;
|
|
<T>(items: Iterable<T>, template: ItemTemplate<T>): unknown;
|
|
<T>(items: Iterable<T>, keyFn: KeyFn<T> | ItemTemplate<T>, template: ItemTemplate<T>): unknown;
|
|
}
|
|
/**
|
|
* A directive that repeats a series of values (usually `TemplateResults`)
|
|
* generated from an iterable, and updates those items efficiently when the
|
|
* iterable changes based on user-provided `keys` associated with each item.
|
|
*
|
|
* Note that if a `keyFn` is provided, strict key-to-DOM mapping is maintained,
|
|
* meaning previous DOM for a given key is moved into the new position if
|
|
* needed, and DOM will never be reused with values for different keys (new DOM
|
|
* will always be created for new keys). This is generally the most efficient
|
|
* way to use `repeat` since it performs minimum unnecessary work for insertions
|
|
* and removals.
|
|
*
|
|
* The `keyFn` takes two parameters, the item and its index, and returns a unique key value.
|
|
*
|
|
* ```js
|
|
* html`
|
|
* <ol>
|
|
* ${repeat(this.items, (item) => item.id, (item, index) => {
|
|
* return html`<li>${index}: ${item.name}</li>`;
|
|
* })}
|
|
* </ol>
|
|
* `
|
|
* ```
|
|
*
|
|
* **Important**: If providing a `keyFn`, keys *must* be unique for all items in a
|
|
* given call to `repeat`. The behavior when two or more items have the same key
|
|
* is undefined.
|
|
*
|
|
* If no `keyFn` is provided, this directive will perform similar to mapping
|
|
* items to values, and DOM will be reused against potentially different items.
|
|
*/
|
|
export declare const repeat: RepeatDirectiveFn;
|
|
/**
|
|
* The type of the class that powers this directive. Necessary for naming the
|
|
* directive's return type.
|
|
*/
|
|
export type { RepeatDirective };
|
|
//# sourceMappingURL=repeat.d.ts.map
|