telegram-miniapp-tools/dist/signals/batch.js

Tools for working with Telegram Miniapps

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.runInBatchMode = runInBatchMode;
exports.batch = batch;
var callbacks;
function runInBatchMode(signal, fn) {
    (callbacks && callbacks.set(signal, fn)) || fn();
}
/**
 * Runs the specified function in the batch mode.
 *
 * It makes all signals' subscribers to be called only after signals changes inside the specified
 * function were applied.
 * @param fn - function to run in the batch mode.
 * @example
 * const a = signal(1);
 * const b = signal(1);
 * const c = computed(() => a() + b());
 *
 * function subscriber(value) {
 *   console.log(value);
 * }
 *
 * c.sub(subscriber);
 *
 * batch(() => {
 *   a.set(2);
 *   a.set(3);
 *   b.set(2);
 *   b.set(3);
 * });
 *
 * // Despite the fact that we called signals setters four times, the `subscriber` function will
 * // be called only once. Removing the `batch` function usage will lead to calling the `subscriber`
 * // function four times.
 */
function batch(fn) {
    // There could be a case when a batch is called inside other batches.
    // In this case, we should just ignore the current call.
    if (callbacks) {
        return fn();
    }
    callbacks = new Map();
    try {
        fn();
    }
    finally {
        callbacks.forEach(function (cb) { return cb(); });
        callbacks = undefined;
        // TODO: What if something went wrong in fn or its callbacks?
    }
}