GitHub mutations observer library script
Tính đến
Script này sẽ không được không được cài đặt trực tiếp. Nó là một thư viện cho các script khác để bao gồm các chỉ thị meta
// @require https://update.greasyfork.org/scripts/28721/882023/mutations.js
/* GitHub mutations observer library script v0.4.3
* Detect changes to various elements and trigger an event
* This script is meant to be used as a library for GitHub-based userscripts
* Copyright © 2020 Rob Garrison
* License: MIT
*/
(() => {
"use strict";
// prefix for event & document body class name, e.g. "ghmo:container"
const prefix = "ghmo",
disableAttr = `data-${prefix}-disable`,
debounceInterval = 200,
targets = {
// pjax container (covers general, repo & gists)
// .news = newsfeed layout
"[data-pjax-container], .news": {
count: 0,
name: "container"
},
// comment preview active
".js-preview-body": {
count: 0,
name: "preview"
},
// .js-discussion = wrapper for progressively loaded comments;
// "# items not shown" example: https://github.com/isaacs/github/issues/18
// .discussion-item = issue status changed (github-issue-show-status)
// #progressive-timeline-item-container = load hidden items (old?)
// #js-progressive-timeline-item-container = load hidden items
".js-discussion, .discussion-item, .toolbar-item, #progressive-timeline-item-container, #js-progressive-timeline-item-container": {
count: 0,
name: "comments"
},
// progressively loaded content (diff files)
".js-diff-progressive-container, .data.blob-wrapper, .js-diff-load-container, .diff-table tbody": {
count: 0,
name: "diff"
},
// issues/pr sidebar & timeline sections: e.g. form actions, commit
// references, deployment state & PR checks container
".js-updatable-content, .js-updatable-content-preserve-scroll-position": {
count: 0,
name: "updatable"
},
// user profile menu (loads on hover)
"details-menu": {
count: 0,
name: "menu"
}
},
list = Object.keys(targets);
function fireEvents() {
list.forEach(selector => {
if (targets[selector].count > 0) {
// event => "ghmo:container", "ghmo:comments"
const event = new Event(prefix + ":" + targets[selector].name);
document.dispatchEvent(event);
}
targets[selector].count = 0;
});
}
function init() {
// prevent error when library is loaded at document-start & no body exists
const container = document.querySelector("body");
let timer;
// prevent script from installing more than once
if (container && !container.classList.contains(prefix + "-enabled")) {
container.classList.add(prefix + "-enabled");
// bound to document.body... this may be bad for performance
// http://stackoverflow.com/a/39332340/145346
new MutationObserver(mutations => {
clearTimeout(timer);
/* document.body attribute used to disable updates; it *should not*
* be used regularly as multiple scripts may enable or disable the
* observers at inappropriate times. It is best that each script handles
* the mutation events triggered by this library on its own
*/
if (container.getAttribute(disableAttr)) {
return;
}
let mindx, target, lindx,
llen = list.length,
mlen = mutations.length;
// avoiding use of forEach loops for performance reasons
for (mindx = 0; mindx < mlen; mindx++) {
target = mutations[mindx].target;
if (target) {
for (lindx = 0; lindx < llen; lindx++) {
if (target.matches(list[lindx])) {
targets[list[lindx]].count++;
}
}
}
timer = setTimeout(() => {
fireEvents();
}, debounceInterval);
}
}).observe(container, {
childList: true,
subtree: true
});
}
}
if (document.readyState === "loading") {
document.addEventListener("DOMContentLoaded", () => init);
} else {
init();
}
})();