Consolidated mutation observer handler for use by other reddit userscripts. By itself doesn't do much, but other scripts and use hooks to avoid redundant observers on the same thing.
اعتبارا من
// ==UserScript==
// @name Reddit Watcher
// @namespace https://lawrenzo.com/p/reddit-watcher
// @description Consolidated mutation observer handler for use by other reddit userscripts. By itself doesn't do much, but other scripts and use hooks to avoid redundant observers on the same thing.
// @version 1.3.2
// @author Lawrence Sim
// @license WTFPL (http://www.wtfpl.net)
// @grant unsafeWindow
// @match *://*.reddit.com/*
// ==/UserScript==
(function() {
if(unsafeWindow && !unsafeWindow.redditWatcher) {
var debug = false;
function watcherAbstract(funcs, opts, name) {
if(typeof funcs === "function") funcs = {get: funcs};
return {
name: name || "unnamed",
defaultOpts: opts || {childList:true},
hooks: {
update: [],
change: []
},
onUpdate: function(task) {
this.hooks.update.push(task);
},
update: function(mutated) {
if(debug) console.log(this.name + " updated");
this.hooks.update.forEach(task => task(this.watching, mutated));
},
onChange: function(task) {
this.hooks.change.push(task);
},
changed: function() {
if(debug) console.log(this.name + " changed");
this.hooks.change.forEach(task => task(this.watching));
},
un: function(func) {
let index = this.hooks.update.indexOf(func);
while(~index) {
this.hooks.update = this.hooks.splice(index, 1);
index = this.hooks.update.indexOf(func);
}
index = this.hooks.change.indexOf(func);
while(~index) {
this.hooks.change = this.change.splice(index, 1);
index = this.hooks.change.indexOf(func);
}
},
watching: null,
watcher: null,
get: funcs.get,
reset: function() {
if(debug) console.log(this.name + " reset");
if(!this.watcher) {
this.watcher = new MutationObserver(this.update.bind(this));
} else {
this.watcher.disconnect();
}
this.update();
this.observe(this.watching, this.defaultOpts);
},
observe: function(elem, opts) {
if(this.watcher) this.watcher.observe(elem, opts);
},
wasChanged: funcs.changed,
check: function() {
if(debug) console.log("checking " + this.name);
if(!this.watching || !document.body.contains(this.watching)) {
let requery = this.get();
if(requery && requery !== this.watching) {
this.watching = requery;
this.changed();
this.reset();
return true;
}
}
if(this.wasChanged && this.wasChanged(this.watching)) {
this.changed();
return true;
}
}
};
}
var lastFeed = null,
lastFirstPost = null;
var feedWatcher = watcherAbstract(
{
get: function() {
let listing = document.querySelector(".ListingLayout-outerContainer"),
posts = listing.querySelectorAll("div[data-testid='post-container']"),
feed = posts && posts.length > 1 && posts[0].parentNode;
while(feed && !feed.nextSibling) {
if(feed == listing) return null;
feed = feed.parentNode || null;
}
return feed && feed.parentNode;
},
changed: function(feed) {
if(lastFeed && lastFeed != feed) {
lastFeed = feed;
return false;
}
if(!lastFeed) lastFeed = feed;
let firstPost = lastFeed && lastFeed.querySelector("div[data-testid='post-container']");
if(firstPost !== lastFirstPost) {
lastFirstPost = firstPost;
return true;
}
}
},
{childList:true},
"feed"
);
var listingWatcher = watcherAbstract(
{get: () => document.querySelector(".ListingLayout-outerContainer")},
{childList:true, subtree:true},
"listing"
);
var bodyWatcher = watcherAbstract(
{get: () => document.body},
{childList:true},
"body"
);
listingWatcher.onChange(() => feedWatcher.check());
listingWatcher.onUpdate(() => feedWatcher.check());
listingWatcher.check();
var wasInFeed = !!listingWatcher.watching;
bodyWatcher.onUpdate(body => {
if(body.querySelectorAll(".ListingLayout-outerContainer div[data-testid='post-container']").length > 1) {
wasInFeed ? listingWatcher.check() : listingWatcher.reset();
wasInFeed = true;
} else {
if(wasInFeed) listingWatcher.watcher && listingWatcher.watcher.disconnect();
wasInFeed = false;
}
});
bodyWatcher.check();
unsafeWindow.redditWatcher = {
body: bodyWatcher,
listing: listingWatcher,
feed: feedWatcher,
update: function() { this.body.update(); }
};
}
})();