Adds time duration labels near each lesson title
// ==UserScript==
// @name Khan Academy timestamps
// @namespace https://www.khanacademy.org/
// @version 1.3
// @description Adds time duration labels near each lesson title
// @author nazikus
// @require http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js
// @match https://www.khanacademy.org/*/*
// @run-at document-end
// ==/UserScript==
/* jshint -W097 */
// TODO speed parameter button to adjust time labels accordingly
// https://developers.google.com/youtube/iframe_api_reference#Queueing_Functions
// TODO progress time on time label (text clipping background)
// http://nimbupani.com/using-background-clip-for-text-with-css-fallback.html
(function() {
'use strict';
console.log = function() {}; // disable debugging logs
// Vocabulary used here to correspond to KhanAcademy website structure:
// - Subject major section (math, science, computing)
// - Supertopic topic containing subtopics (Intergral Calculus)
// - Topic contains video lessons (Vector and Spaces, Integrals)
// - Module groups lessons of a single topic
// - Lesson actual video lesson (contains links to other lesons in a module)
var startProcessing = function(){
var currUrl = window.location.href;
// CASE Lesson - video lesson page
// Check if url contains a directory with a single character (e.g., '/v/', '/e/', etc)
if ( /\/\w\/[\w\-]+$/.test(currUrl) ) {
processLessonPage();
}
// CASE Topic - Topic page with Table of Contents (ToC)
// valid url examples:
// https://www.khanacademy.org/math/linear-algebra/vectors-and-spaces
// https://www.khanacademy.org/math/calculus-home/integral-calculus/indefinite-definite-integrals
// Check if current path has a sufficient depth for topic page and contains a ToC <div>
else if ([6,7].indexOf(currUrl.split('/').length) >= 0 && $('div[class^="contents"]').length ){
processTopicPage();
}
// Case Subject - page containing all the topics in the subject or supertopic
// valid url examples:
// https://www.khanacademy.org/math/linear-algebra
// https://www.khanacademy.org/math/calculus-home/integral-calculus
// Check if current path has a sufficient depth for subject/supertopic page and contains Topics <span>
else if ([5,6].indexOf(currUrl.split('/').length) >= 0 && $('span:contains("Topics")').length ){
processSubjectPage();
}
// Skip the rest
else {
console.log('No topics to label here, skipping...');
}
};
////////////////////////////////////////////////////////////////////////////////
var processLessonPage = function() {
console.log('Lesson page processing started...');
var hrefs = $('div[class^="tutorialNavOnSide"] a');
// create placeholder for Time Duration label of each lesson (master for cloning)
var labelClass = hrefs.find('div[class^="title"]').attr('class');
var labelMaster = $('<span>', {class: labelClass}).css({'float':'left'});
// select module header (where module time label to be appended)
var moduleLabelTarget = $('div[class^="navHeaderOnSide"]').eq(0);
// create placholder for Module Time Duration label with cumulated time (master for cloning)
var moduleLabelMaster = $('<span>').css({'float':'left'});
var moduleTimer = moduleTimerFactory(hrefs.length, {
targetEl: moduleLabelTarget,
labelEl: moduleLabelMaster.clone(),
title: moduleLabelTarget.find('a').text(),
});
hrefs.each( (function(labelToClone, modTimer) {
return function(idx, lessonHref){
var href = $(lessonHref);
var labelTarget = href.find('div[class^="info"]');
var lessonUrl = href.attr('href');
// get rgb colors of play button (as num array)
var bg = href.find('div[class^="circle"]:first').css('background');
var c = (bg ? bg.match(/rgb\((\d+),\s*(\d+),\s*(\d+)\)/).slice(1).map(function(v){return ~~v;}) : [0,0,0]);
// naive rgb channels deviation
var rgbDev = c.map(function(v){return Math.abs(v-this);},
c.reduce(function(s,v){return s+v;},0)/c.length )
.reduce(function(s,v){return s+v;})/c.length;
var isLessonPassed = rgbDev > 20; // if not white/grey button
// time duration label object
var labelObject = {
targetEl: labelTarget,
labelEl: labelToClone.clone(),
title: href.text(),
isPassed: isLessonPassed
};
// FETCH URL
fetchAndAppendVideoDurationLabel(lessonUrl, labelObject, modTimer);
};
})(labelMaster, moduleTimer) );
};
////////////////////////////////////////////////////////////////////////////////
var processTopicPage = function() {
console.log('Topic page processing starged...');
// cleanup (while debugging)
// $('span[class^="nodeTitle"]').remove();
// $('span[style^="float: right"]').remove();
// select topic modules, skip (slice) first div which is ToC
var topicModules = $('div[class^="moduleList"] > div[class^="module"]').slice(1);
// create placeholder for time duration label of each lesson (master for cloning)
var labelClass = topicModules.find('> div > a div[class^="nodeTitle"]').attr('class'),
labelColor = $('div[class^="header"][style^="background"').css('background-color'),
labelMaster = $('<span>', {class: labelClass}).css({'float':'right', 'color': labelColor});
// create placholder for Module Time Duration label with cumulated time (master for cloning)
var moduleLabelMaster = $('<span>').css({'float':'right'}),
topicLabel = $('<span>');
$('h1[class^="title"]').after( topicLabel );
var topicTimerInstance = topicTimerFactory(topicModules.length, topicLabel);
console.log('Modules in topic: %s', topicModules.length);
// iterate over each topic module in a separate worker
topicModules.each(function(){
window.setTimeout(function(that, lMaster, mlMaster, topicTimerInst){
var hrefs = $(that).find('> div > a');
// get all hrefs links in current module
// get urls as string array (for debugging)
// var urls = hrefs.map(function(){return this.href;}).get();
// change dipslay alignment of divs containing time label
hrefs.find('div[class^="nodeTitle"]').css('display', 'inline-block');
// select module header (where module time label to be appended)
var moduleLabelTarget = $(that).find('> h2 > div[style^="color:"]');
var moduleObject = {
targetEl: moduleLabelTarget,
labelEl: mlMaster.clone(),
title: moduleLabelTarget.find('a').text(),
};
// module time tracker, lesson counter & label creation
var moduleTimer = moduleTimerFactory(hrefs.length, moduleObject, topicTimerInst);
var moduleHasVideos = hrefs.map(function(){ return Boolean( $(this).attr('href').match(/\/v\/[\w\-]+$/) );})
.toArray().reduce(function(s,v){return s+v;},0) > 0;
if (hrefs.length === 0) { topicTimerInst.decSize(); }
if (!moduleHasVideos) { topicTimerInst.decSize(); }
console.log('Module "%s", lessons %d', moduleObject.title, hrefs.length);
// Info: extra closure here is to pass params into $.each()'s lambda
hrefs.each( (function(labelToClone, modTimer){
return function(idx, lessonHref){
var href = $(lessonHref),
labelTarget = href.find('> div[class^="nodeInfo"]'),
lessonUrl = href.attr('href');
// get rgb colors of play button (as num array)
var bg = href.find('div[class^="circle"]:first').css('background');
var c = (bg ? bg.match(/rgb\((\d+),\s*(\d+),\s*(\d+)\)/).slice(1).map(function(v){return ~~v;}) : [0,0,0]);
// naive rgb channels deviation
var rgbDev = c.map(function(v){return Math.abs(v-this);},
c.reduce(function(s,v){return s+v;},0)/c.length )
.reduce(function(s,v){return s+v;})/c.length;
var isLessonPassed = rgbDev > 20; // if not white/grey button
// time duration label object
var labelObject = {
targetEl: labelTarget,
labelEl: labelToClone.clone(),
title: href.text(),
isPassed: isLessonPassed
};
// FETCH URL
fetchAndAppendVideoDurationLabel(lessonUrl, labelObject, modTimer);
};})(lMaster, moduleTimer, topicTimerInst) ); // return hrefs.each()
}, 0, this, labelMaster, moduleLabelMaster, topicTimerInstance); // return window.setTimeout()
}); // return topicModules.each();
};
////////////////////////////////////////////////////////////////////////////////
var processSubjectPage = function(){
console.log('Subject page processing started...');
var subjTiming = {sec: 0, secFin: 0};
var topicHrefs = $('div[class^="linkArea"] > div[class^="link"] > a');
var c = 0;
var uMap = ['/calculus-home/precalculus', '/algebra-home/precalculus'];
console.log('urls in subject: %s', topicHrefs.length);
// iterate over links, get their timings from cache
topicHrefs.each(function(){
var href = $(this),
url = href.attr('href'),
urlKey = url.indexOf(uMap[0])>-1 ? url.replace(uMap[0],uMap[1]): url;
var cachedT = localStorage.getItem(urlKey);
console.log('url %s: %s', href.attr('href'), cachedT);
if (cachedT){
var cachedTs = cachedT.split('|');
href.parent().css({'line-height':'1em', 'padding-bottom':'5px'});
href.append('<br>'+cachedTs[2]);
subjTiming.sec += ~~cachedTs[0];
subjTiming.secFin += ~~cachedTs[1];
c++;
}
});
if (c === topicHrefs.length){
var s = subjTiming.sec, f = subjTiming.secFin;
$('div[class^="header"]').css('flex-flow', 'row wrap');
$('h1[class^="title"]').after( $('<span>').css({'width':'100%','margin-top':'-50px','font-size':'1.4em'})
.text( formatSeconds(s, f) ) );
localStorage.setItem(location.pathname, s+'|'+f+'|'+formatSeconds(s,f));
}
};
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/////////////////// UTILITY FACTORIES & ASYNC FUNCTIONS //////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
// starts requests (one for video page, and one for YouTube API),
// parses them out, caches, and appends corresponding time labels to DOM in async
var fetchAndAppendVideoDurationLabel = function(lessonUrl, labelObject, moduleTimer){
// if url is not a video lesson (eg, exercise or read material)
if ( !(/\/v\//.test(lessonUrl)) ) {
// just append empty time duration and continue to the next link
labelObject.labelEl.text('[--:--]');
labelObject.targetEl.append( labelObject.labelEl );
moduleTimer.decSize(); // non-video lessons do not contribute to module time
return ; // true - continue, false - break from $.each()
}
// check if lesson time duration is cached yet
var cachedTd = localStorage.getItem(lessonUrl);
if (cachedTd) {
labelObject.labelEl.text( cachedTd.split('|')[1] );
labelObject.targetEl.append( labelObject.labelEl );
moduleTimer.addTime( ~~cachedTd.split('|')[0], labelObject.isPassed ? ~~cachedTd.split('|')[0] : 0 );
console.log('Cached: (%s) %s', labelObject.title, cachedTd.split('|')[1]);
return ;
}
var api = 'https://www.googleapis.com/youtube/v3/videos?id={id}&part=contentDetails&key={yek}';
var h = 'cmQyAhWMshjc2Go8HAnmOWhzauSnIkBfBySazIA';
// get lesson page html in async request (inside a worker)
var lessonHtml = $.ajax({
url: lessonUrl,
datatype: 'html',
labObj: labelObject,
modTimer: moduleTimer
})
.done(function(htmlData){
// get youtube video id
var videoId = $($.parseHTML(htmlData))
.filter('meta[property="og:video"]').attr('content').split('/').pop();
// perform async YouTube API call to get video duration
$.ajax({
url: api.replace('\x7b\x69\x64\x7d', videoId)
.replace('\x7b\x79\x65\x6b\x7d', h.split('').reverse().join('')),
datatype: 'json',
lObj: this.labObj,
mTimer: this.modTimer,
vLessonUrl: this.url,
success: function(jsonResponse){
var duration = jsonResponse.items[0]
.contentDetails.duration.match(/PT(\d+H)?(\d+M)?(\d+S)?/);
var hours = (parseInt(duration[1]) || 0),
minutes = (parseInt(duration[2]) || 0),
seconds = (parseInt(duration[3]) || 0),
totalSec = hours * 3600 + minutes * 60 + seconds,
stamp = formatSeconds(totalSec);
// attach cloned label to the DOM
this.lObj.labelEl.text( stamp );
this.lObj.targetEl.append( this.lObj.labelEl );
// cache lesson time duration
localStorage.setItem(this.vLessonUrl, totalSec+'|'+this.lObj.labelEl.text());
console.log('(%s) %s. %s %s', this.mTimer.getLabel().title,
this.mTimer.getCount(), this.lObj.title, stamp);
// MODULE TIMING
this.mTimer.addTime( totalSec, this.lObj.isPassed ? totalSec : 0);
},
error: function(data) { console.error('YouTube API error:\n%s', data); }
}); // YouTube $.ajax():success
}) // lesson $.ajax().done()
.fail(function(){ console.error('Could not retrieve URL: %s', this.url); });
}; // fetchAndAppendVideoDurationLabel()
// factory (closure) for counting processed lessons (hrefs), cummulating module
// total time and attaching corresponding time label to DOM.
// Invoked for each topic module separately
var moduleTimerFactory = function(numberOfLessons, moduleLabelObj, topicTimer){
var totalSeconds = 0,
totalSecondsFinished = 0,
lessonsCount = 0,
moduleSize = numberOfLessons,
mlObj = moduleLabelObj;
// if its the last lesson link to process in the module, then
// insert module (total) time label near module title (target)
var checkAndAttachToDom = function(){
if (lessonsCount >= moduleSize){
mlObj.labelEl.text( formatSeconds(totalSeconds,totalSecondsFinished) );
mlObj.targetEl.append( mlObj.labelEl );
if (topicTimer) topicTimer.addTime(totalSeconds, totalSecondsFinished)
}
};
return {
// some lessons are not video lessons, so skip those and decrease size
getCount: function(){ return lessonsCount; },
getLabel: function(){ return moduleLabelObj; },
decSize: function(){ moduleSize--; checkAndAttachToDom(); },
addTime: function(seconds, secondsFinished) {
totalSeconds += seconds;
totalSecondsFinished += secondsFinished;
lessonsCount++;
checkAndAttachToDom();
},
};
};
// factory (closure) for counting modules, cummulating module
// total time and attaching corresponding time label to DOM.
// Invoked once during topic page processing
var topicTimerFactory = function(numberOfModules, targetEl){
var topicSeconds = 0,
topicSecondsFinished = 0,
topicSize = numberOfModules,
moduleCount = 0;
// if its the last module to process in the topic, then
// insert topic (total) time label in topic header title (targetEl)
var checkAndAttachToDom = function(){
if (moduleCount >= topicSize){
console.log("Topic timing: %s", formatSeconds(topicSeconds, topicSecondsFinished));
var timerStr = formatSeconds(topicSeconds,topicSecondsFinished);
targetEl.text( timerStr );
// update topic timer value in cache, to be used in processSubjectPage();
localStorage.setItem(window.location.pathname, topicSeconds+'|'+topicSecondsFinished+'|'+timerStr);
}
};
return{
decSize: function(){ topicSize--; checkAndAttachToDom(); },
addTime: function(seconds, secondsFinished) {
topicSeconds += seconds;
topicSecondsFinished += secondsFinished;
moduleCount++;
console.log("Module #%s %s", moduleCount, formatSeconds(seconds, secondsFinished));
checkAndAttachToDom();
}
};
};
////////////////////////////////////////////////////////////////////////////////
// helper function to format number of seconds to label string to be displayed
var formatSeconds = function(seconds, secondsFinished){
var hours = Math.floor(seconds/60/60),
minutes = Math.floor(seconds/60) - hours*60;
var totalStr = (hours ? ( String(hours).length>2 ? String(hours) : ('0'+hours).slice(-2)+':') : '') +
('0'+minutes).slice(-2) +':'+ ('0'+seconds%60).slice(-2);
var finishedStr = '';
if (secondsFinished) {
var fHours = Math.floor(secondsFinished/60/60),
fMinutes = Math.floor(secondsFinished/60) - fHours*60,
fSeconds = secondsFinished;
// hourse, not fHourse, to force HH-zeros if no finished hours
finishedStr = (hours?('0'+fHours).slice(-2)+':':'') + ('0'+fMinutes).slice(-2) +':'+ ('0'+fSeconds%60).slice(-2) + ' / ';
}
return '[' + finishedStr + totalStr + ']';
};
///////////////////////////////
///////////////////////////////
//// START THE WHOLE THING ////
///////////////////////////////
///////////////////////////////
startProcessing();
})();
// alternative to YouTube API:
// http://stackoverflow.com/questions/30084140/youtube-video-title-with-api-v3-without-api-key