69ee8fd96a
* Add commercial licence and update config files * Update license in headers * Revert "Update license in headers" This reverts commit 7ed7949485e88889a9ffc8075a9df1f8e936777e. * Update only spdx id * Remove LicenseRef- from package.json LicenseRef- no longer allowed in npm v3 package.json This fixes the warning in the logs and failing build check.
80 lines
2.5 KiB
TypeScript
80 lines
2.5 KiB
TypeScript
/*
|
|
Copyright 2024 New Vector Ltd.
|
|
Copyright 2020 The Matrix.org Foundation C.I.C.
|
|
|
|
SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
|
|
Please see LICENSE files in the repository root for full details.
|
|
*/
|
|
|
|
import { logger } from "matrix-js-sdk/src/logger";
|
|
|
|
import { IDestroyable } from "./IDestroyable";
|
|
import { arrayFastClone } from "./arrays";
|
|
|
|
export type WhenFn<T extends string | number> = (w: Whenable<T>) => void;
|
|
|
|
/**
|
|
* Whenables are a cheap way to have Observable patterns mixed with typical
|
|
* usage of Promises, without having to tear down listeners or calls. Whenables
|
|
* are intended to be used when a condition will be met multiple times and
|
|
* the consumer needs to know *when* that happens.
|
|
*/
|
|
export abstract class Whenable<T extends string | number> implements IDestroyable {
|
|
private listeners: { condition: T | null; fn: WhenFn<T> }[] = [];
|
|
|
|
/**
|
|
* Sets up a call to `fn` *when* the `condition` is met.
|
|
* @param condition The condition to match.
|
|
* @param fn The function to call.
|
|
* @returns This.
|
|
*/
|
|
public when(condition: T, fn: WhenFn<T>): Whenable<T> {
|
|
this.listeners.push({ condition, fn });
|
|
return this;
|
|
}
|
|
|
|
/**
|
|
* Sets up a call to `fn` *when* any of the `conditions` are met.
|
|
* @param conditions The conditions to match.
|
|
* @param fn The function to call.
|
|
* @returns This.
|
|
*/
|
|
public whenAnyOf(conditions: T[], fn: WhenFn<T>): Whenable<T> {
|
|
for (const condition of conditions) {
|
|
this.when(condition, fn);
|
|
}
|
|
return this;
|
|
}
|
|
|
|
/**
|
|
* Sets up a call to `fn` *when* any condition is met.
|
|
* @param fn The function to call.
|
|
* @returns This.
|
|
*/
|
|
public whenAnything(fn: WhenFn<T>): Whenable<T> {
|
|
this.listeners.push({ condition: null, fn });
|
|
return this;
|
|
}
|
|
|
|
/**
|
|
* Notifies all the listeners of a given condition.
|
|
* @param condition The new condition that has been met.
|
|
*/
|
|
protected notifyCondition(condition: T): void {
|
|
const listeners = arrayFastClone(this.listeners); // clone just in case the handler modifies us
|
|
for (const listener of listeners) {
|
|
if (listener.condition === null || listener.condition === condition) {
|
|
try {
|
|
listener.fn(this);
|
|
} catch (e) {
|
|
logger.error(`Error calling whenable listener for ${condition}:`, e);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
public destroy(): void {
|
|
this.listeners = [];
|
|
}
|
|
}
|