site/node_modules/mathjax-full/ts/util/Retries.ts

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2024-10-14 06:09:33 +00:00
/*************************************************************
*
* Copyright (c) 2017-2022 The MathJax Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview Implements methods for handling asynchronous actions
*
* @author dpvc@mathjax.org (Davide Cervone)
*/
/*****************************************************************/
/*
* The legacy MathJax object (FIXME: remove this after all v2 code is gone)
*/
declare var MathJax: {Callback: {After: Function}};
/*****************************************************************/
/**
* Allow us to pass a promise as part of an Error object
*/
export interface RetryError extends Error {
retry: Promise<any>;
}
/*****************************************************************/
/**
* A wrapper for actions that may be asynchronous. This will
* rerun the action after the asychronous action completes.
* Usually, this is for dynamic loading of files. Legacy
* MathJax does that a lot, so we still need it for now, but
* may be able to go without it in the future.
*
* Example:
*
* HandleRetriesFor(() => {
*
* html.findMath()
* .compile()
* .getMetrics()
* .typeset()
* .updateDocument();
*
* }).catch(err => {
* console.log(err.message);
* });
*
* @param {Function} code The code to run that might cause retries
* @return {Promise} A promise that is satisfied when the code
* runs completely, and fails if the code
* generates an error (that is not a retry).
*/
export function handleRetriesFor(code: Function): Promise<any> {
return new Promise(function run(ok: Function, fail: Function) {
try {
ok(code());
} catch (err) {
if (err.retry && err.retry instanceof Promise) {
err.retry.then(() => run(ok, fail))
.catch((perr: Error) => fail(perr));
} else if (err.restart && err.restart.isCallback) {
// FIXME: Remove this branch when all legacy code is gone
MathJax.Callback.After(() => run(ok, fail), err.restart);
} else {
fail(err);
}
}
});
}
/*****************************************************************/
/**
* Tells HandleRetriesFor() to wait for this promise to be fulfilled
* before rerunning the code. Causes an error to be thrown, so
* calling this terminates the code at that point.
*
* @param {Promise} promise The promise that must be satisfied before
* actions will continue
*/
export function retryAfter(promise: Promise<any>) {
let err = new Error('MathJax retry') as RetryError;
err.retry = promise;
throw err;
}