yomichan/ext/mixed/js/dynamic-loader.js
2020-04-22 17:48:42 -04:00

83 lines
2.7 KiB
JavaScript

/*
* Copyright (C) 2020 Yomichan Authors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
const dynamicLoader = (() => {
function loadStyles(urls) {
const parent = document.head;
for (const url of urls) {
const node = parent.querySelector(`link[href='${escapeCSSAttribute(url)}']`);
if (node !== null) { continue; }
const style = document.createElement('link');
style.rel = 'stylesheet';
style.type = 'text/css';
style.href = url;
parent.appendChild(style);
}
}
function loadScripts(urls) {
return new Promise((resolve) => {
const parent = document.body;
for (const url of urls) {
const node = parent.querySelector(`script[src='${escapeCSSAttribute(url)}']`);
if (node !== null) { continue; }
const script = document.createElement('script');
script.async = false;
script.src = url;
parent.appendChild(script);
}
loadScriptSentinel(resolve);
});
}
function loadScriptSentinel(resolve, reject) {
const parent = document.body;
const script = document.createElement('script');
const sentinelEventName = 'dynamicLoaderSentinel';
const sentinelEventCallback = (e) => {
if (e.script !== script) { return; }
yomichan.off(sentinelEventName, sentinelEventCallback);
parent.removeChild(script);
resolve();
};
yomichan.on(sentinelEventName, sentinelEventCallback);
try {
script.async = false;
script.src = '/mixed/js/dynamic-loader-sentinel.js';
parent.appendChild(script);
} catch (e) {
yomichan.off(sentinelEventName, sentinelEventCallback);
reject(e);
}
}
function escapeCSSAttribute(value) {
return value.replace(/['\\]/g, (character) => `\\${character}`);
}
return {
loadStyles,
loadScripts
};
})();