☰

mutations

GitHub mutations observer library script

Tính đến 14-04-2017. Xem phiên bản mới nhất.

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/28721/188072/mutations.js 

/* GitHub mutations observer library script v0.1.5
 * Detect changes to various elements and trigger an event
 * Copyright © 2017 Rob Garrison
 * License: MIT
 */
/* jshint esnext:true, unused:true */
(() => {
	"use strict";

	// prefix for event & document body class name, e.g. "ghmo:container"
	const prefix = "ghmo",
		targets = {
			// pjax container (covers general, repo & gists)
			"[data-pjax-container]": {
				count: 0,
				name: "container"
			},
			// comment preview active
			".js-preview-body": {
				count: 0,
				name: "preview"
			},
			// progressively loaded comments; "# items not shown"
			// example: https://github.com/isaacs/github/issues/18
			".js-discussion": {
				count: 0,
				name: "comments"
			},
			// progressively loaded content (diff files)
			".js-diff-progressive-container, .data.blob-wrapper, .js-diff-load-container": {
				count: 0,
				name: "diff"
			}
		},
		list = Object.keys(targets),
		container = document.querySelector("body");

	let timer;

	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;
		});
	}

	// prevent script from installing more than once
	if (!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);
			let mindx, target, lindx,
				llen = list.length,
				mlen = mutations.length;
			for (mindx = 0; mindx < mlen; mindx++) {
				target = mutations[mindx].target;
				if (target) {
					for (lindx = 0; lindx < llen; lindx++) {
						if (target.matches(list[lindx])) {
							targets[lindx].count++;
						}
					}
				}
				timer = setTimeout(() => {
					fireEvents();
				}, 200);
			}
		}).observe(container, {
			childList: true,
			subtree: true
		});

	}

})();