By Chris Done
Has 2 other scripts.
// ==UserScript==
// @name 4chan updater
// @namespace http://img.4chan.org/
// @description Script to update 4chan threads at user defined interval
// @include http://*.4chan.org/*/res/*.html*
// ==/UserScript==
// TODO: Add preference panel so prefs don't have to be hand edited in the source
// TODO: Add out-of-band form submit via ajax so the user can stay on the page.
(function() { // vim won't indent correctly without this -> )
// PREFERENCES: Change these to suit your taste.
const POLL_INTERVAL = 10; // how often to poll the server (in seconds)
const START_ON_PAGE_LOAD = false; // start updating automatically
const ALERT_WHEN_THREAD_DIES = false; // show alert dialog when thread dies
const DISABLE_FORMS_WHEN_THREAD_DIES = true; // prevent submitting to dead thread
const TITLE_WHEN_THREAD_DIES = '(THREAD DIED)'; // window/tab title
const NOTICE_WHEN_THREAD_DIES = 'This thread no longer exists';
const STARTED_CAPTION = 'Updater Running';
const STOPPED_CAPTION = 'Updater Stopped';
const THREAD_DIED_CAPTION = 'Thread Died';
// Allow 4chan extension and other Greasemonkey scripts to run on new posts.
// It takes more a bit more computing so don't use it unless you need it.
const RUN_SCRIPTS_ON_NEW_POSTS = true;
const DEBUG = false; // turn this on to get log messages
// END PREFERENCES
var last_update = null;
var monitor_div = null;
var monitor_link = null;
/* poll_timer pseudo-object to get all this shite in one place */
var poll_timer = {
id : null,
is_running: function() { return this.id },
start: function() {
if (this.is_running()) {
log_msg('timer already started { %s }, skipping', this.id);
} else {
log_msg('starting timer');
this.id = window.setInterval(poll_server, 1000 * POLL_INTERVAL);
}
},
stop: function() {
log_msg('stop timer');
clearInterval(this.id);
this.id = null;
}
}
// FUNCTIONS
function init_updater()
{
// bail if called on a framed document.
if (window.frameElement &&
window.parent.location.href.replace(/#.*/, '') == location.href) {
return;
}
last_update = new Date(document.lastModified);
set_up_controls();
START_ON_PAGE_LOAD && start_updater();
}
function set_up_controls()
{
GM_addStyle('#bupdater_monitor_div { color: #FFF; padding: 3px; border: 1px; position:fixed; bottom:2px; right:0px; }');
GM_addStyle('#bupdater_thread_died { color:red; text-align:center }');
GM_addStyle('div.running { background-color: #0A0; }');
GM_addStyle('div.thread404d { background-color: #A00; }');
GM_addStyle('div.stopped { background-color: #000; }');
monitor_link = document.createElement('a');
monitor_link.setAttribute('id', 'bupdater_monitor_link');
monitor_link.addEventListener('click', toggle_updater, false);
monitor_link.style.cursor = 'pointer';
monitor_link.style.color = 'white';
monitor_link.innerHTML = STOPPED_CAPTION;
monitor_div = document.createElement('div');
monitor_div.setAttribute('id', 'bupdater_monitor_div');
monitor_div.setAttribute('class', 'stopped');
monitor_div.appendChild(monitor_link);
$X('/html/body').appendChild(monitor_div);
}
function toggle_updater() {
poll_timer.is_running() ? stop_updater() : start_updater();
}
function start_updater()
{
monitor_link.innerHTML = STARTED_CAPTION;
monitor_div.setAttribute('class', 'running');
poll_timer.start();
}
function stop_updater()
{
monitor_link.innerHTML = STOPPED_CAPTION;
monitor_div.setAttribute('class', 'stopped');
poll_timer.stop();
}
function poll_server()
{
log_msg('polling server...');
var request = new XMLHttpRequest();
request.onreadystatechange = function () {
if (request.readyState == 4) {
switch (request.status) {
case 200: // OK
log_msg('updating page');
update_page(request);
// NOTE: update_page is responsible
// for restarting timer when it's done
break;
case 304: // Not Modified
log_msg('page not modified');
poll_timer.start();
break;
case 404: // Not Found
log_msg('thread died');
do_thread_died();
break;
default:
log_msg('unhandled server response: ' + request.status);
poll_timer.start();
break;
}
}
}
try {
poll_timer.stop(); // until request is handled
req_type = RUN_SCRIPTS_ON_NEW_POSTS ? 'HEAD' : 'GET';
request.open(req_type, window.location.href.replace(/#.*/, ''), true);
request.setRequestHeader('If-Modified-Since', last_update.toUTCString());
request.send(null);
} catch (e) {
log_msg('Error connecting to server: ' + e.toString());
}
}
function handle_iframe_loaded(iframe_doc)
{
var container = null;
var insert_func = null;
var last_item = null;
// dont try to run on 404'd pages
if (!iframe_doc.getElementById("navtop")) {
return;
}
last_update = new Date(iframe_doc.lastModified);
// FIXME: All these xpaths need major optimization
if ( (container = $X("//div[@class='4chan_ext_thread_replies']")) ) {
add_post = function(item, cont) { cont.appendChild(item); }
} else {
container = $X("//form[@name='delform']");
last_item = $X("//form[@name='delform']//table[last()-1]", document);
add_post = function(item, cont) {
cont.insertBefore(item, last_item.nextSibling);
}
}
current_reply_count =
$X("count(//form[@name='delform']//td[@class='reply' or @class='replyhl'])", document);
new_replies = $x("//form[@name='delform']//table[position() > " +
current_reply_count +
"]//td[@class='reply' or @class='replyhl']/ancestor::table",
iframe_doc);
for (var i = 0; i < new_replies.length; i++) {
add_post(new_replies[i], container);
}
poll_timer.start();
}
function update_page(request)
{
if (request.responseText) {
last_update = new Date(request.getResponseHeader('Last-Modified'));
document.getElementsByName('delform')[0].innerHTML =
request.responseText.split(/<form .*?name=["]delform["].*?>/i)[1];
// rerun 4chan's script to highlight replies
unsafeWindow.init();
poll_timer.start();
} else {
// HACK HACK: we can't reload the main page into an iframe due to
// a recursion guard mechanism in Fireflodge so we call
// 'dat.4chan.org' and let it redirect back to img.4chan.org.
// This both bypasses the guard and makes me cringe.
url = window.location.href.replace(/#.*/, '').replace('img','dat');
dom_from_hidden_iframe(url, handle_iframe_loaded); // NOTE: handle_iframe_loaded restarts timer when page rendering is done.
}
}
function do_thread_died()
{
stop_updater();
// display thread died message
var delform = document.getElementsByName('delform')[0];
thread_died_message = document.createElement('h2');
thread_died_message.setAttribute('id', 'bupdater_thread_died');
thread_died_message.innerHTML = NOTICE_WHEN_THREAD_DIES;
delform.parentNode.insertBefore(thread_died_message, delform);
monitor_link.innerHTML = THREAD_DIED_CAPTION;
monitor_div.setAttribute('class', 'thread404d');
// add thread died message to page title
document.title = TITLE_WHEN_THREAD_DIES;
// disable forms if the user requested
DISABLE_FORMS_WHEN_THREAD_DIES && disable_forms();
// do alert dialog if the user requested one
ALERT_WHEN_THREAD_DIES && alert(NOTICE_WHEN_THREAD_DIES);
}
function disable_forms()
{
// change submit button title so the user knows why it's disabled
$X("/html/body//form[@name='post']//input[@type='submit']").value =
TITLE_WHEN_THREAD_DIES;
// disable all inputs but textarea so the user can copy their text still
// if they want to save or use it somewhere else.
inputs = $x("/html/body//form//input");
for (i = 0; i < inputs.length; i++) {
inputs[i].disabled='true';
}
}
// list nodes matching this expression, optionally relative to the node `root'
function $x( xpath, root )
{
var doc = root ? root.evaluate ? root : root.ownerDocument : document, next;
var got = doc.evaluate( xpath, root||doc, null, 0, null ), result = [];
switch (got.resultType) {
case got.STRING_TYPE:
return got.stringValue;
case got.NUMBER_TYPE:
return got.numberValue;
case got.BOOLEAN_TYPE:
return got.booleanValue;
default:
while ((next = got.iterateNext()))
result.push( next );
return result;
}
}
function $X( xpath, root )
{
var got = $x( xpath, root );
return got instanceof Array ? got[0] : got;
}
function log_msg(msg)
{
DEBUG && console.log(msg);
}
function dom_from_hidden_iframe(url, cb/*( xml )*/) {
function loaded() {
doc = iframe.contentDocument;
iframe.removeEventListener('load', loaded, false);
doc.removeEventListener('DOMContentLoaded', loaded, false);
// avoid racing with GM's DOMContentLoaded callback
setTimeout(function() { cb( doc ); }, 10);
};
var iframe = null;
if ( !(iframe = document.getElementById('updater_iframe')) ) {
iframe = document.createElement('iframe');
iframe.style.height = iframe.style.width = '0';
iframe.style.visibility = 'hidden';
iframe.style.position = 'absolute';
iframe.id = 'updater_iframe';
document.body.appendChild(iframe);
}
iframe.addEventListener('load', loaded, false);
log_msg('loading new content into iframe');
try {
iframe.src = url;
} catch(e) {
log_msg('Error in another script in the iframe');
}
}
window.addEventListener("load", function() { init_updater(); }, false);
})();
