signal-desktop/js/reliable_trigger.js
2021-09-17 14:27:53 -04:00

140 lines
4.1 KiB
JavaScript

// Copyright 2017-2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
/* eslint-disable */
// This file was taken from Backbone and then modified. It does not conform to this
// project's standards.
(function () {
'use strict';
// Note: this is all the code required to customize Backbone's trigger() method to make
// it resilient to exceptions thrown by event handlers. Indentation and code styles
// were kept inline with the Backbone implementation for easier diffs.
// The changes are:
// 1. added 'name' parameter to triggerEvents to give it access to the
// current event name
// 2. added try/catch handlers to triggerEvents with error logging inside
// every while loop
// And of course, we update the protoypes of Backbone.Model/Backbone.View as well as
// Backbone.Events itself
const arr = [];
const slice = arr.slice;
// Regular expression used to split event strings.
const eventSplitter = /\s+/;
// Implement fancy features of the Events API such as multiple event
// names `"change blur"` and jQuery-style event maps `{change: action}`
// in terms of the existing API.
const eventsApi = function (obj, action, name, rest) {
if (!name) return true;
// Handle event maps.
if (typeof name === 'object') {
for (const key in name) {
obj[action](...[key, name[key]].concat(rest));
}
return false;
}
// Handle space separated event names.
if (eventSplitter.test(name)) {
const names = name.split(eventSplitter);
for (let i = 0, l = names.length; i < l; i++) {
obj[action](...[names[i]].concat(rest));
}
return false;
}
return true;
};
// A difficult-to-believe, but optimized internal dispatch function for
// triggering events. Tries to keep the usual cases speedy (most internal
// Backbone events have 3 arguments).
const triggerEvents = function (events, name, args) {
let ev,
i = -1,
l = events.length,
a1 = args[0],
a2 = args[1],
a3 = args[2];
const logError = function (error) {
window.SignalWindow.log.error(
'Model caught error triggering',
name,
'event:',
error && error.stack ? error.stack : error
);
};
switch (args.length) {
case 0:
while (++i < l) {
try {
(ev = events[i]).callback.call(ev.ctx);
} catch (error) {
logError(error);
}
}
return;
case 1:
while (++i < l) {
try {
(ev = events[i]).callback.call(ev.ctx, a1);
} catch (error) {
logError(error);
}
}
return;
case 2:
while (++i < l) {
try {
(ev = events[i]).callback.call(ev.ctx, a1, a2);
} catch (error) {
logError(error);
}
}
return;
case 3:
while (++i < l) {
try {
(ev = events[i]).callback.call(ev.ctx, a1, a2, a3);
} catch (error) {
logError(error);
}
}
return;
default:
while (++i < l) {
try {
(ev = events[i]).callback.apply(ev.ctx, args);
} catch (error) {
logError(error);
}
}
}
};
// Trigger one or many events, firing all bound callbacks. Callbacks are
// passed the same arguments as `trigger` is, apart from the event name
// (unless you're listening on `"all"`, which will cause your callback to
// receive the true name of the event as the first argument).
function trigger(name) {
if (!this._events) return this;
const args = slice.call(arguments, 1);
if (!eventsApi(this, 'trigger', name, args)) return this;
const events = this._events[name];
const allEvents = this._events.all;
if (events) triggerEvents(events, name, args);
if (allEvents) triggerEvents(allEvents, name, arguments);
return this;
}
Backbone.Model.prototype.trigger = Backbone.View.prototype.trigger = Backbone.Collection.prototype.trigger = Backbone.Events.trigger = trigger;
})();