Merge pull request #3084 from AHOHNMYC/js-helpers-polyfills

JS refactoring part 2: helper functions, poyfills

assets/js/_helpers.js

@@ -0,0 +1,249 @@
+'use strict';
+// Contains only auxiliary methods
+// May be included and executed unlimited number of times without any consequences
+
+// Polyfills for IE11
+Array.prototype.find = Array.prototype.find || function (condition) {
+    return this.filter(condition)[0];
+};
+Array.from = Array.from || function (source) {
+    return Array.prototype.slice.call(source);
+};
+NodeList.prototype.forEach = NodeList.prototype.forEach || function (callback) {
+    Array.from(this).forEach(callback);
+};
+String.prototype.includes = String.prototype.includes || function (searchString) {
+    return this.indexOf(searchString) >= 0;
+};
+String.prototype.startsWith = String.prototype.startsWith || function (prefix) {
+    return this.substr(0, prefix.length) === prefix;
+};
+Math.sign = Math.sign || function(x) {
+    x = +x;
+    if (!x) return x; // 0 and NaN
+    return x > 0 ? 1 : -1;
+};
+if (!window.hasOwnProperty('HTMLDetailsElement') && !window.hasOwnProperty('mockHTMLDetailsElement')) {
+    window.mockHTMLDetailsElement = true;
+    const style = 'details:not([open]) > :not(summary) {display: none}';
+    document.head.appendChild(document.createElement('style')).textContent = style;
+
+    addEventListener('click', function (e) {
+        if (e.target.nodeName !== 'SUMMARY') return;
+        const details = e.target.parentElement;
+        if (details.hasAttribute('open'))
+            details.removeAttribute('open');
+        else
+            details.setAttribute('open', '');
+    });
+}
+
+// Monstrous global variable for handy code
+// Includes: clamp, xhr, storage.{get,set,remove}
+window.helpers = window.helpers || {
+    /**
+     * https://en.wikipedia.org/wiki/Clamping_(graphics)
+     * @param {Number} num Source number
+     * @param {Number} min Low border
+     * @param {Number} max High border
+     * @returns {Number} Clamped value
+     */
+    clamp: function (num, min, max) {
+        if (max < min) {
+            var t = max; max = min; min = t; // swap max and min
+        }
+
+        if (max < num)
+            return max;
+        if (min > num)
+            return min;
+        return num;
+    },
+
+    /** @private */
+    _xhr: function (method, url, options, callbacks) {
+        const xhr = new XMLHttpRequest();
+        xhr.open(method, url);
+
+        // Default options
+        xhr.responseType = 'json';
+        xhr.timeout = 10000;
+        // Default options redefining
+        if (options.responseType)
+            xhr.responseType = options.responseType;
+        if (options.timeout)
+            xhr.timeout = options.timeout;
+
+        if (method === 'POST')
+            xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
+
+        // better than onreadystatechange because of 404 codes https://stackoverflow.com/a/36182963
+        xhr.onloadend = function () {
+            if (xhr.status === 200) {
+                if (callbacks.on200) {
+                    // fix for IE11. It doesn't convert response to JSON
+                    if (xhr.responseType === '' && typeof(xhr.response) === 'string')
+                        callbacks.on200(JSON.parse(xhr.response));
+                    else
+                        callbacks.on200(xhr.response);
+                }
+            } else {
+                // handled by onerror
+                if (xhr.status === 0) return;
+
+                if (callbacks.onNon200)
+                    callbacks.onNon200(xhr);
+            }
+        };
+
+        xhr.ontimeout = function () {
+            if (callbacks.onTimeout)
+                callbacks.onTimeout(xhr);
+        };
+
+        xhr.onerror = function () {
+            if (callbacks.onError)
+                callbacks.onError(xhr);
+        };
+
+        if (options.payload)
+            xhr.send(options.payload);
+        else
+            xhr.send();
+    },
+    /** @private */
+    _xhrRetry: function(method, url, options, callbacks) {
+        if (options.retries <= 0) {
+            console.warn('Failed to pull', options.entity_name);
+            if (callbacks.onTotalFail)
+                callbacks.onTotalFail();
+            return;
+        }
+        helpers._xhr(method, url, options, callbacks);
+    },
+    /**
+     * @callback callbackXhrOn200
+     * @param {Object} response - xhr.response
+     */
+    /**
+     * @callback callbackXhrError
+     * @param {XMLHttpRequest} xhr
+     */
+    /**
+     * @param {'GET'|'POST'} method - 'GET' or 'POST'
+     * @param {String} url - URL to send request to
+     * @param {Object} options - other XHR options
+     * @param {XMLHttpRequestBodyInit} [options.payload=null] - payload for POST-requests
+     * @param {'arraybuffer'|'blob'|'document'|'json'|'text'} [options.responseType=json]
+     * @param {Number} [options.timeout=10000]
+     * @param {Number} [options.retries=1]
+     * @param {String} [options.entity_name='unknown'] - string to log
+     * @param {Number} [options.retry_timeout=1000]
+     * @param {Object} callbacks - functions to execute on events fired
+     * @param {callbackXhrOn200} [callbacks.on200]
+     * @param {callbackXhrError} [callbacks.onNon200]
+     * @param {callbackXhrError} [callbacks.onTimeout]
+     * @param {callbackXhrError} [callbacks.onError]
+     * @param {callbackXhrError} [callbacks.onTotalFail] - if failed after all retries
+     */
+     xhr: function(method, url, options, callbacks) {
+        if (!options.retries || options.retries <= 1) {
+            helpers._xhr(method, url, options, callbacks);
+            return;
+        }
+
+        if (!options.entity_name) options.entity_name = 'unknown';
+        if (!options.retry_timeout) options.retry_timeout = 1000;
+        const retries_total = options.retries;
+        let currentTry = 1;
+
+        const retry = function () {
+            console.warn('Pulling ' + options.entity_name + ' failed... ' + (currentTry++) + '/' + retries_total);
+            setTimeout(function () {
+                options.retries--;
+                helpers._xhrRetry(method, url, options, callbacks);
+            }, options.retry_timeout);
+        };
+
+        // Pack retry() call into error handlers
+        callbacks._onError = callbacks.onError;
+        callbacks.onError = function (xhr) {
+            if (callbacks._onError)
+                callbacks._onError(xhr);
+            retry();
+        };
+        callbacks._onTimeout = callbacks.onTimeout;
+        callbacks.onTimeout = function (xhr) {
+            if (callbacks._onTimeout)
+                callbacks._onTimeout(xhr);
+            retry();
+        };
+
+        helpers._xhrRetry(method, url, options, callbacks);
+    },
+
+    /**
+     * @typedef {Object} invidiousStorage
+     * @property {(key:String) => Object} get
+     * @property {(key:String, value:Object)} set
+     * @property {(key:String)} remove
+     */
+
+    /**
+     * Universal storage, stores and returns JS objects. Uses inside localStorage or cookies
+     * @type {invidiousStorage}
+     */
+    storage: (function () {
+        // access to localStorage throws exception in Tor Browser, so try is needed
+        let localStorageIsUsable = false;
+        try{localStorageIsUsable = !!localStorage.setItem;}catch(e){}
+
+        if (localStorageIsUsable) {
+            return {
+                get: function (key) {
+                    if (!localStorage[key]) return;
+                    try {
+                        return JSON.parse(decodeURIComponent(localStorage[key]));
+                    } catch(e) {
+                        // Erase non parsable value
+                        helpers.storage.remove(key);
+                    }
+                },
+                set: function (key, value) { localStorage[key] = encodeURIComponent(JSON.stringify(value)); },
+                remove: function (key) { localStorage.removeItem(key); }
+            };
+        }
+
+        // TODO: fire 'storage' event for cookies
+        console.info('Storage: localStorage is disabled or unaccessible. Cookies used as fallback');
+        return {
+            get: function (key) {
+                const cookiePrefix = key + '=';
+                function findCallback(cookie) {return cookie.startsWith(cookiePrefix);}
+                const matchedCookie = document.cookie.split('; ').find(findCallback);
+                if (matchedCookie) {
+                    const cookieBody = matchedCookie.replace(cookiePrefix, '');
+                    if (cookieBody.length === 0) return;
+                    try {
+                        return JSON.parse(decodeURIComponent(cookieBody));
+                    } catch(e) {
+                        // Erase non parsable value
+                        helpers.storage.remove(key);
+                    }
+                }
+            },
+            set: function (key, value) {
+                const cookie_data = encodeURIComponent(JSON.stringify(value));
+
+                // Set expiration in 2 year
+                const date = new Date();
+                date.setFullYear(date.getFullYear()+2);
+
+                document.cookie = key + '=' + cookie_data + '; expires=' + date.toGMTString();
+            },
+            remove: function (key) {
+                document.cookie = key + '=; Max-Age=0';
+            }
+        };
+    })()
+};

assets/js/community.js

@@ -1,13 +1,6 @@
 'use strict';
 var community_data = JSON.parse(document.getElementById('community_data').textContent);
 
-String.prototype.supplant = function (o) {
-    return this.replace(/{([^{}]*)}/g, function (a, b) {
-        var r = o[b];
-        return typeof r === 'string' || typeof r === 'number' ? r : a;
-    });
-};
-
 function hide_youtube_replies(event) {
     var target = event.target;
 
@@ -38,13 +31,6 @@ function show_youtube_replies(event) {
     target.setAttribute('data-sub-text', sub_text);
 }
 
-function number_with_separator(val) {
-    while (/(\d+)(\d{3})/.test(val.toString())) {
-        val = val.toString().replace(/(\d+)(\d{3})/, '$1' + ',' + '$2');
-    }
-    return val;
-}
-
 function get_youtube_replies(target, load_more) {
     var continuation = target.getAttribute('data-continuation');
 
@@ -58,47 +44,39 @@ function get_youtube_replies(target, load_more) {
         '&hl=' + community_data.preferences.locale +
         '&thin_mode=' + community_data.preferences.thin_mode +
         '&continuation=' + continuation;
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('GET', url, true);
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('GET', url, {}, {
-        if (xhr.readyState === 4) {
+        on200: function (response) {
-            if (xhr.status === 200) {
+            if (load_more) {
-                if (load_more) {
+                body = body.parentNode.parentNode;
-                    body = body.parentNode.parentNode;
+                body.removeChild(body.lastElementChild);
-                    body.removeChild(body.lastElementChild);
+                body.innerHTML += response.contentHtml;
-                    body.innerHTML += xhr.response.contentHtml;
-                } else {
-                    body.removeChild(body.lastElementChild);
-
-                    var p = document.createElement('p');
-                    var a = document.createElement('a');
-                    p.appendChild(a);
-
-                    a.href = 'javascript:void(0)';
-                    a.onclick = hide_youtube_replies;
-                    a.setAttribute('data-sub-text', community_data.hide_replies_text);
-                    a.setAttribute('data-inner-text', community_data.show_replies_text);
-                    a.innerText = community_data.hide_replies_text;
-
-                    var div = document.createElement('div');
-                    div.innerHTML = xhr.response.contentHtml;
-
-                    body.appendChild(p);
-                    body.appendChild(div);
-                }
             } else {
-                body.innerHTML = fallback;
+                body.removeChild(body.lastElementChild);
+
+                var p = document.createElement('p');
+                var a = document.createElement('a');
+                p.appendChild(a);
+
+                a.href = 'javascript:void(0)';
+                a.onclick = hide_youtube_replies;
+                a.setAttribute('data-sub-text', community_data.hide_replies_text);
+                a.setAttribute('data-inner-text', community_data.show_replies_text);
+                a.textContent = community_data.hide_replies_text;
+
+                var div = document.createElement('div');
+                div.innerHTML = response.contentHtml;
+
+                body.appendChild(p);
+                body.appendChild(div);
             }
+        },
+        onNon200: function (xhr) {
+            body.innerHTML = fallback;
+        },
+        onTimeout: function (xhr) {
+            console.warn('Pulling comments failed');
+            body.innerHTML = fallback;
         }
-    };
+    });
-
-    xhr.ontimeout = function () {
-        console.warn('Pulling comments failed.');
-        body.innerHTML = fallback;
-    };
-
-    xhr.send();
 }

assets/js/embed.js

@@ -1,14 +1,7 @@
 'use strict';
 var video_data = JSON.parse(document.getElementById('video_data').textContent);
 
-function get_playlist(plid, retries) {
+function get_playlist(plid) {
-    if (retries === undefined) retries = 5;
-
-    if (retries <= 0) {
-        console.warn('Failed to pull playlist');
-        return;
-    }
-
     var plid_url;
     if (plid.startsWith('RD')) {
         plid_url = '/api/v1/mixes/' + plid +
@@ -21,85 +14,49 @@ function get_playlist(plid, retries) {
             '&format=html&hl=' + video_data.preferences.locale;
     }
 
-    var xhr = new XMLHttpRequest();
+    helpers.xhr('GET', plid_url, {retries: 5, entity_name: 'playlist'}, {
-    xhr.responseType = 'json';
+        on200: function (response) {
-    xhr.timeout = 10000;
+            if (!response.nextVideo)
-    xhr.open('GET', plid_url, true);
+                return;
 
-    xhr.onreadystatechange = function () {
+            player.on('ended', function () {
-        if (xhr.readyState === 4) {
+                var url = new URL('https://example.com/embed/' + response.nextVideo);
-            if (xhr.status === 200) {
-                if (xhr.response.nextVideo) {
-                    player.on('ended', function () {
-                        var url = new URL('https://example.com/embed/' + xhr.response.nextVideo);
 
-                        url.searchParams.set('list', plid);
+                url.searchParams.set('list', plid);
-                        if (!plid.startsWith('RD')) {
+                if (!plid.startsWith('RD'))
-                            url.searchParams.set('index', xhr.response.index);
+                    url.searchParams.set('index', response.index);
-                        }
+                if (video_data.params.autoplay || video_data.params.continue_autoplay)
+                    url.searchParams.set('autoplay', '1');
+                if (video_data.params.listen !== video_data.preferences.listen)
+                    url.searchParams.set('listen', video_data.params.listen);
+                if (video_data.params.speed !== video_data.preferences.speed)
+                    url.searchParams.set('speed', video_data.params.speed);
+                if (video_data.params.local !== video_data.preferences.local)
+                    url.searchParams.set('local', video_data.params.local);
 
-                        if (video_data.params.autoplay || video_data.params.continue_autoplay) {
+                location.assign(url.pathname + url.search);
-                            url.searchParams.set('autoplay', '1');
+            });
-                        }
-
-                        if (video_data.params.listen !== video_data.preferences.listen) {
-                            url.searchParams.set('listen', video_data.params.listen);
-                        }
-
-                        if (video_data.params.speed !== video_data.preferences.speed) {
-                            url.searchParams.set('speed', video_data.params.speed);
-                        }
-
-                        if (video_data.params.local !== video_data.preferences.local) {
-                            url.searchParams.set('local', video_data.params.local);
-                        }
-
-                        location.assign(url.pathname + url.search);
-                    });
-                }
-            }
         }
-    };
+    });
-
-    xhr.onerror = function () {
-        console.warn('Pulling playlist failed... ' + retries + '/5');
-        setTimeout(function () { get_playlist(plid, retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        console.warn('Pulling playlist failed... ' + retries + '/5');
-        get_playlist(plid, retries - 1);
-    };
-
-    xhr.send();
 }
 
-window.addEventListener('load', function (e) {
+addEventListener('load', function (e) {
     if (video_data.plid) {
         get_playlist(video_data.plid);
     } else if (video_data.video_series) {
         player.on('ended', function () {
             var url = new URL('https://example.com/embed/' + video_data.video_series.shift());
 
-            if (video_data.params.autoplay || video_data.params.continue_autoplay) {
+            if (video_data.params.autoplay || video_data.params.continue_autoplay)
                 url.searchParams.set('autoplay', '1');
-            }
+            if (video_data.params.listen !== video_data.preferences.listen)
-
-            if (video_data.params.listen !== video_data.preferences.listen) {
                 url.searchParams.set('listen', video_data.params.listen);
-            }
+            if (video_data.params.speed !== video_data.preferences.speed)
-
-            if (video_data.params.speed !== video_data.preferences.speed) {
                 url.searchParams.set('speed', video_data.params.speed);
-            }
+            if (video_data.params.local !== video_data.preferences.local)
-
-            if (video_data.params.local !== video_data.preferences.local) {
                 url.searchParams.set('local', video_data.params.local);
-            }
+            if (video_data.video_series.length !== 0)
-
-            if (video_data.video_series.length !== 0) {
                 url.searchParams.set('playlist', video_data.video_series.join(','));
-            }
 
             location.assign(url.pathname + url.search);
         });

assets/js/handlers.js

@@ -1,8 +1,6 @@
 'use strict';
 
 (function () {
-    var n2a = function (n) { return Array.prototype.slice.call(n); };
-
     var video_player = document.getElementById('player_html5_api');
     if (video_player) {
         video_player.onmouseenter = function () { video_player['data-title'] = video_player['title']; video_player['title'] = ''; };
@@ -11,8 +9,8 @@
     }
 
     // For dynamically inserted elements
-    document.addEventListener('click', function (e) {
+    addEventListener('click', function (e) {
-        if (!e || !e.target) { return; }
+        if (!e || !e.target) return;
 
         var t = e.target;
         var handler_name = t.getAttribute('data-onclick');
@@ -29,6 +27,7 @@
                 get_youtube_replies(t, load_more, load_replies);
                 break;
             case 'toggle_parent':
+                e.preventDefault();
                 toggle_parent(t);
                 break;
             default:
@@ -36,118 +35,98 @@
         }
     });
 
-    n2a(document.querySelectorAll('[data-mouse="switch_classes"]')).forEach(function (e) {
+    document.querySelectorAll('[data-mouse="switch_classes"]').forEach(function (el) {
-        var classes = e.getAttribute('data-switch-classes').split(',');
+        var classes = el.getAttribute('data-switch-classes').split(',');
-        var ec = classes[0];
+        var classOnEnter = classes[0];
-        var lc = classes[1];
+        var classOnLeave = classes[1];
-        var onoff = function (on, off) {
+        function toggle_classes(toAdd, toRemove) {
-            var cs = e.getAttribute('class');
+            el.classList.add(toAdd);
-            cs = cs.split(off).join(on);
+            el.classList.remove(toRemove);
-            e.setAttribute('class', cs);
+        }
-        };
+        el.onmouseenter = function () { toggle_classes(classOnEnter, classOnLeave); };
-        e.onmouseenter = function () { onoff(ec, lc); };
+        el.onmouseleave = function () { toggle_classes(classOnLeave, classOnEnter); };
-        e.onmouseleave = function () { onoff(lc, ec); };
     });
 
-    n2a(document.querySelectorAll('[data-onsubmit="return_false"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onsubmit="return_false"]').forEach(function (el) {
-        e.onsubmit = function () { return false; };
+        el.onsubmit = function () { return false; };
     });
 
-    n2a(document.querySelectorAll('[data-onclick="mark_watched"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="mark_watched"]').forEach(function (el) {
-        e.onclick = function () { mark_watched(e); };
+        el.onclick = function () { mark_watched(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="mark_unwatched"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="mark_unwatched"]').forEach(function (el) {
-        e.onclick = function () { mark_unwatched(e); };
+        el.onclick = function () { mark_unwatched(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="add_playlist_video"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="add_playlist_video"]').forEach(function (el) {
-        e.onclick = function () { add_playlist_video(e); };
+        el.onclick = function () { add_playlist_video(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="add_playlist_item"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="add_playlist_item"]').forEach(function (el) {
-        e.onclick = function () { add_playlist_item(e); };
+        el.onclick = function () { add_playlist_item(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="remove_playlist_item"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="remove_playlist_item"]').forEach(function (el) {
-        e.onclick = function () { remove_playlist_item(e); };
+        el.onclick = function () { remove_playlist_item(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="revoke_token"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="revoke_token"]').forEach(function (el) {
-        e.onclick = function () { revoke_token(e); };
+        el.onclick = function () { revoke_token(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="remove_subscription"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="remove_subscription"]').forEach(function (el) {
-        e.onclick = function () { remove_subscription(e); };
+        el.onclick = function () { remove_subscription(el); };
     });
-    n2a(document.querySelectorAll('[data-onclick="notification_requestPermission"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onclick="notification_requestPermission"]').forEach(function (el) {
-        e.onclick = function () { Notification.requestPermission(); };
+        el.onclick = function () { Notification.requestPermission(); };
     });
 
-    n2a(document.querySelectorAll('[data-onrange="update_volume_value"]')).forEach(function (e) {
+    document.querySelectorAll('[data-onrange="update_volume_value"]').forEach(function (el) {
-        var cb = function () { update_volume_value(e); };
+        function update_volume_value() {
-        e.oninput = cb;
+            document.getElementById('volume-value').textContent = el.value;
-        e.onchange = cb;
+        }
+        el.oninput = update_volume_value;
+        el.onchange = update_volume_value;
     });
 
-    function update_volume_value(element) {
-        document.getElementById('volume-value').innerText = element.value;
-    }
 
     function revoke_token(target) {
         var row = target.parentNode.parentNode.parentNode.parentNode.parentNode;
         row.style.display = 'none';
         var count = document.getElementById('count');
-        count.innerText = count.innerText - 1;
+        count.textContent--;
 
-        var referer = window.encodeURIComponent(document.location.href);
         var url = '/token_ajax?action_revoke_token=1&redirect=false' +
-            '&referer=' + referer +
+            '&referer=' + encodeURIComponent(location.href) +
             '&session=' + target.getAttribute('data-session');
-        var xhr = new XMLHttpRequest();
-        xhr.responseType = 'json';
-        xhr.timeout = 10000;
-        xhr.open('POST', url, true);
-        xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-        xhr.onreadystatechange = function () {
+        var payload = 'csrf_token=' + target.parentNode.querySelector('input[name="csrf_token"]').value;
-            if (xhr.readyState === 4) {
+
-                if (xhr.status !== 200) {
+        helpers.xhr('POST', url, {payload: payload}, {
-                    count.innerText = parseInt(count.innerText) + 1;
+            onNon200: function (xhr) {
-                    row.style.display = '';
+                count.textContent++;
-                }
+                row.style.display = '';
             }
-        };
+        });
-
-        var csrf_token = target.parentNode.querySelector('input[name="csrf_token"]').value;
-        xhr.send('csrf_token=' + csrf_token);
     }
 
     function remove_subscription(target) {
         var row = target.parentNode.parentNode.parentNode.parentNode.parentNode;
         row.style.display = 'none';
         var count = document.getElementById('count');
-        count.innerText = count.innerText - 1;
+        count.textContent--;
 
-        var referer = window.encodeURIComponent(document.location.href);
         var url = '/subscription_ajax?action_remove_subscriptions=1&redirect=false' +
-            '&referer=' + referer +
+            '&referer=' + encodeURIComponent(location.href) +
             '&c=' + target.getAttribute('data-ucid');
-        var xhr = new XMLHttpRequest();
-        xhr.responseType = 'json';
-        xhr.timeout = 10000;
-        xhr.open('POST', url, true);
-        xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-        xhr.onreadystatechange = function () {
+        var payload = 'csrf_token=' + target.parentNode.querySelector('input[name="csrf_token"]').value;
-            if (xhr.readyState === 4) {
+
-                if (xhr.status !== 200) {
+        helpers.xhr('POST', url, {payload: payload}, {
-                    count.innerText = parseInt(count.innerText) + 1;
+            onNon200: function (xhr) {
-                    row.style.display = '';
+                count.textContent++;
-                }
+                row.style.display = '';
             }
-        };
+        });
-
-        var csrf_token = target.parentNode.querySelector('input[name="csrf_token"]').value;
-        xhr.send('csrf_token=' + csrf_token);
     }
 
     // Handle keypresses
-    window.addEventListener('keydown', function (event) {
+    addEventListener('keydown', function (event) {
         // Ignore modifier keys
         if (event.ctrlKey || event.metaKey) return;
 

assets/js/notifications.js

@@ -1,43 +1,26 @@
 'use strict';
 var notification_data = JSON.parse(document.getElementById('notification_data').textContent);
 
+/** Boolean meaning 'some tab have stream' */
+const STORAGE_KEY_STREAM = 'stream';
+/** Number of notifications. May be increased or reset */
+const STORAGE_KEY_NOTIF_COUNT = 'notification_count';
+
 var notifications, delivered;
+var notifications_mock = { close: function () { } };
 
-function get_subscriptions(callback, retries) {
+function get_subscriptions() {
-    if (retries === undefined) retries = 5;
+    helpers.xhr('GET', '/api/v1/auth/subscriptions?fields=authorId', {
-
+        retries: 5,
-    if (retries <= 0) {
+        entity_name: 'subscriptions'
-        return;
+    }, {
-    }
+        on200: create_notification_stream
-
+    });
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('GET', '/api/v1/auth/subscriptions?fields=authorId', true);
-
-    xhr.onreadystatechange = function () {
-        if (xhr.readyState === 4) {
-            if (xhr.status === 200) {
-                var subscriptions = xhr.response;
-                callback(subscriptions);
-            }
-        }
-    };
-
-    xhr.onerror = function () {
-        console.warn('Pulling subscriptions failed... ' + retries + '/5');
-        setTimeout(function () { get_subscriptions(callback, retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        console.warn('Pulling subscriptions failed... ' + retries + '/5');
-        get_subscriptions(callback, retries - 1);
-    };
-
-    xhr.send();
 }
 
 function create_notification_stream(subscriptions) {
+    // sse.js can't be replaced to EventSource in place as it lack support of payload and headers
+    // see https://developer.mozilla.org/en-US/docs/Web/API/EventSource/EventSource
     notifications = new SSE(
         '/api/v1/auth/notifications?fields=videoId,title,author,authorId,publishedText,published,authorThumbnails,liveNow', {
             withCredentials: true,
@@ -49,96 +32,100 @@ function create_notification_stream(subscriptions) {
     var start_time = Math.round(new Date() / 1000);
 
     notifications.onmessage = function (event) {
-        if (!event.id) {
+        if (!event.id) return;
-            return;
-        }
 
         var notification = JSON.parse(event.data);
         console.info('Got notification:', notification);
 
-        if (start_time < notification.published && !delivered.includes(notification.videoId)) {
+        // Ignore not actual and delivered notifications
-            if (Notification.permission === 'granted') {
+        if (start_time > notification.published || delivered.includes(notification.videoId)) return;
-                var system_notification =
-                    new Notification((notification.liveNow ? notification_data.live_now_text : notification_data.upload_text).replace('`x`', notification.author), {
-                        body: notification.title,
-                        icon: '/ggpht' + new URL(notification.authorThumbnails[2].url).pathname,
-                        img: '/ggpht' + new URL(notification.authorThumbnails[4].url).pathname,
-                        tag: notification.videoId
-                    });
 
-                system_notification.onclick = function (event) {
+        delivered.push(notification.videoId);
-                    window.open('/watch?v=' + event.currentTarget.tag, '_blank');
-                };
-            }
 
-            delivered.push(notification.videoId);
+        let notification_count = helpers.storage.get(STORAGE_KEY_NOTIF_COUNT) || 0;
-            localStorage.setItem('notification_count', parseInt(localStorage.getItem('notification_count') || '0') + 1);
+        notification_count++;
-            var notification_ticker = document.getElementById('notification_ticker');
+        helpers.storage.set(STORAGE_KEY_NOTIF_COUNT, notification_count);
 
-            if (parseInt(localStorage.getItem('notification_count')) > 0) {
+        update_ticker_count();
-                notification_ticker.innerHTML =
+
-                    '<span id="notification_count">' + localStorage.getItem('notification_count') + '</span> <i class="icon ion-ios-notifications"></i>';
+        // permission for notifications handled on settings page. JS handler is in handlers.js
-            } else {
+        if (window.Notification && Notification.permission === 'granted') {
-                notification_ticker.innerHTML =
+            var notification_text = notification.liveNow ? notification_data.live_now_text : notification_data.upload_text;
-                    '<i class="icon ion-ios-notifications-outline"></i>';
+            notification_text = notification_text.replace('`x`', notification.author);
-            }
+
+            var system_notification = new Notification(notification_text, {
+                body: notification.title,
+                icon: '/ggpht' + new URL(notification.authorThumbnails[2].url).pathname,
+                img: '/ggpht' + new URL(notification.authorThumbnails[4].url).pathname
+            });
+
+            system_notification.onclick = function (e) {
+                open('/watch?v=' + notification.videoId, '_blank');
+            };
         }
     };
 
-    notifications.addEventListener('error', handle_notification_error);
+    notifications.addEventListener('error', function (e) {
+        console.warn('Something went wrong with notifications, trying to reconnect...');
+        notifications = notifications_mock;
+        setTimeout(get_subscriptions, 1000);
+    });
+
     notifications.stream();
 }
 
-function handle_notification_error(event) {
+function update_ticker_count() {
-    console.warn('Something went wrong with notifications, trying to reconnect...');
+    var notification_ticker = document.getElementById('notification_ticker');
-    notifications = { close: function () { } };
+
-    setTimeout(function () { get_subscriptions(create_notification_stream); }, 1000);
+    const notification_count = helpers.storage.get(STORAGE_KEY_STREAM);
+    if (notification_count > 0) {
+        notification_ticker.innerHTML =
+            '<span id="notification_count">' + notification_count + '</span> <i class="icon ion-ios-notifications"></i>';
+    } else {
+        notification_ticker.innerHTML =
+            '<i class="icon ion-ios-notifications-outline"></i>';
+    }
 }
 
-window.addEventListener('load', function (e) {
+function start_stream_if_needed() {
-    localStorage.setItem('notification_count', document.getElementById('notification_count') ? document.getElementById('notification_count').innerText : '0');
+    // random wait for other tabs set 'stream' flag
-
+    setTimeout(function () {
-    if (localStorage.getItem('stream')) {
+        if (!helpers.storage.get(STORAGE_KEY_STREAM)) {
-        localStorage.removeItem('stream');
+            // if no one set 'stream', set it by yourself and start stream
-    } else {
+            helpers.storage.set(STORAGE_KEY_STREAM, true);
-        setTimeout(function () {
+            notifications = notifications_mock;
-            if (!localStorage.getItem('stream')) {
+            get_subscriptions();
-                notifications = { close: function () { } };
-                localStorage.setItem('stream', true);
-                get_subscriptions(create_notification_stream);
-            }
-        }, Math.random() * 1000 + 50);
-    }
-
-    window.addEventListener('storage', function (e) {
-        if (e.key === 'stream' && !e.newValue) {
-            if (notifications) {
-                localStorage.setItem('stream', true);
-            } else {
-                setTimeout(function () {
-                    if (!localStorage.getItem('stream')) {
-                        notifications = { close: function () { } };
-                        localStorage.setItem('stream', true);
-                        get_subscriptions(create_notification_stream);
-                    }
-                }, Math.random() * 1000 + 50);
-            }
-        } else if (e.key === 'notification_count') {
-            var notification_ticker = document.getElementById('notification_ticker');
-
-            if (parseInt(e.newValue) > 0) {
-                notification_ticker.innerHTML =
-                    '<span id="notification_count">' + e.newValue + '</span> <i class="icon ion-ios-notifications"></i>';
-            } else {
-                notification_ticker.innerHTML =
-                    '<i class="icon ion-ios-notifications-outline"></i>';
-            }
         }
-    });
+    }, Math.random() * 1000 + 50); // [0.050 .. 1.050) second
-});
+}
 
-window.addEventListener('unload', function (e) {
+
-    if (notifications) {
+addEventListener('storage', function (e) {
-        localStorage.removeItem('stream');
+    if (e.key === STORAGE_KEY_NOTIF_COUNT)
+        update_ticker_count();
+
+    // if 'stream' key was removed
+    if (e.key === STORAGE_KEY_STREAM && !helpers.storage.get(STORAGE_KEY_STREAM)) {
+        if (notifications) {
+            // restore it if we have active stream
+            helpers.storage.set(STORAGE_KEY_STREAM, true);
+        } else {
+            start_stream_if_needed();
+        }
     }
 });
+
+addEventListener('load', function () {
+    var notification_count_el = document.getElementById('notification_count');
+    var notification_count = notification_count_el ? parseInt(notification_count_el.textContent) : 0;
+    helpers.storage.set(STORAGE_KEY_NOTIF_COUNT, notification_count);
+
+    if (helpers.storage.get(STORAGE_KEY_STREAM))
+        helpers.storage.remove(STORAGE_KEY_STREAM);
+    start_stream_if_needed();
+});
+
+addEventListener('unload', function () {
+    // let chance to other tabs to be a streamer via firing 'storage' event
+    if (notifications) helpers.storage.remove(STORAGE_KEY_STREAM);
+});

assets/js/player.js

@@ -42,45 +42,53 @@ embed_url = location.origin + '/embed/' + video_data.id + embed_url.search;
 var save_player_pos_key = 'save_player_pos';
 
 videojs.Vhs.xhr.beforeRequest = function(options) {
-    if (options.uri.indexOf('videoplayback') === -1 && options.uri.indexOf('local=true') === -1) {
+    // set local if requested not videoplayback
-        options.uri = options.uri + '?local=true';
+    if (!options.uri.includes('videoplayback')) {
+        if (!options.uri.includes('local=true'))
+            options.uri += '?local=true';
     }
     return options;
 };
 
 var player = videojs('player', options);
 
-player.on('error', () => {
+player.on('error', function () {
-    if (video_data.params.quality !== 'dash') {
+    if (video_data.params.quality === 'dash') return;
-        if (!player.currentSrc().includes("local=true") && !video_data.local_disabled) {
+
-            var currentSources = player.currentSources();
+    var localNotDisabled = (
-            for (var i = 0; i < currentSources.length; i++) {
+        !player.currentSrc().includes('local=true') && !video_data.local_disabled
-                currentSources[i]["src"] += "&local=true"
+    );
-            }
+    var reloadMakesSense = (
-            player.src(currentSources)
+        player.error().code === MediaError.MEDIA_ERR_NETWORK ||
-        }
+        player.error().code === MediaError.MEDIA_ERR_SRC_NOT_SUPPORTED
-        else if (player.error().code === 2 || player.error().code === 4) {
+    );
-            setTimeout(function (event) {
+
-                console.log('An error occurred in the player, reloading...');
+    if (localNotDisabled) {
-    
+        // add local=true to all current sources
-                var currentTime = player.currentTime();
+        player.src(player.currentSources().map(function (source) {
-                var playbackRate = player.playbackRate();
+            source.src += '&local=true';
-                var paused = player.paused();
+        }));
-    
+    } else if (reloadMakesSense) {
-                player.load();
+        setTimeout(function () {
-    
+            console.warn('An error occurred in the player, reloading...');
-                if (currentTime > 0.5) currentTime -= 0.5;
+
-    
+            // After load() all parameters are reset. Save them
-                player.currentTime(currentTime);
+            var currentTime = player.currentTime();
-                player.playbackRate(playbackRate);
+            var playbackRate = player.playbackRate();
-    
+            var paused = player.paused();
-                if (!paused) player.play();
+
-            }, 10000);
+            player.load();
-        }
+
+            if (currentTime > 0.5) currentTime -= 0.5;
+
+            player.currentTime(currentTime);
+            player.playbackRate(playbackRate);
+            if (!paused) player.play();
+        }, 5000);
     }
 });
 
-if (video_data.params.quality == 'dash') {
+if (video_data.params.quality === 'dash') {
     player.reloadSourceOnError({
         errorInterval: 10
     });
@@ -89,7 +97,7 @@ if (video_data.params.quality == 'dash') {
 /**
  * Function for add time argument to url
  * @param {String} url
- * @returns urlWithTimeArg
+ * @returns {URL} urlWithTimeArg
  */
 function addCurrentTimeToURL(url) {
     var urlUsed = new URL(url);
@@ -112,18 +120,12 @@ var shareOptions = {
     description: player_data.description,
     image: player_data.thumbnail,
     get embedCode() {
-        return '<iframe id="ivplayer" width="640" height="360" src="' +
+        // Single quotes inside here required. HTML inserted as is into value attribute of input
-            addCurrentTimeToURL(embed_url) + '" style="border:none;"></iframe>';
+        return "<iframe id='ivplayer' width='640' height='360' src='" +
+            addCurrentTimeToURL(embed_url) + "' style='border:none;'></iframe>";
     }
 };
 
-const storage = (function () {
-    try { if (localStorage.length !== -1) return localStorage; }
-    catch (e) { console.info('No storage available: ' + e); }
-
-    return undefined;
-})();
-
 if (location.pathname.startsWith('/embed/')) {
     var overlay_content = '<h1><a rel="noopener" target="_blank" href="' + location.origin + '/watch?v=' + video_data.id + '">' + player_data.title + '</a></h1>';
     player.overlay({
@@ -162,7 +164,7 @@ if (isMobile()) {
     buttons.forEach(function (child) {primary_control_bar.removeChild(child);});
 
     var operations_bar_element = operations_bar.el();
-    operations_bar_element.className += ' mobile-operations-bar';
+    operations_bar_element.classList.add('mobile-operations-bar');
     player.addChild(operations_bar);
 
     // Playback menu doesn't work when it's initialized outside of the primary control bar
@@ -175,8 +177,8 @@ if (isMobile()) {
         operations_bar_element.append(share_element);
 
         if (video_data.params.quality === 'dash') {
-                var http_source_selector = document.getElementsByClassName('vjs-http-source-selector vjs-menu-button')[0];
+            var http_source_selector = document.getElementsByClassName('vjs-http-source-selector vjs-menu-button')[0];
-                operations_bar_element.append(http_source_selector);
+            operations_bar_element.append(http_source_selector);
         }
     });
 }
@@ -220,14 +222,14 @@ player.playbackRate(video_data.params.speed);
  * Method for getting the contents of a cookie
  *
  * @param {String} name Name of cookie
- * @returns cookieValue
+ * @returns {String|null} cookieValue
  */
 function getCookieValue(name) {
-    var value = document.cookie.split(';').filter(function (item) {return item.includes(name + '=');});
+    var cookiePrefix = name + '=';
-
+    var matchedCookie = document.cookie.split(';').find(function (item) {return item.includes(cookiePrefix);});
-    return (value.length >= 1)
+    if (matchedCookie)
-        ? value[0].substring((name + '=').length, value[0].length)
+        return matchedCookie.replace(cookiePrefix, '');
-        : null;
+    return null;
 }
 
 /**
@@ -257,11 +259,11 @@ function updateCookie(newVolume, newSpeed) {
     date.setTime(date.getTime() + 63115200);
 
     var ipRegex = /^((\d+\.){3}\d+|[A-Fa-f0-9]*:[A-Fa-f0-9:]*:[A-Fa-f0-9:]+)$/;
-    var domainUsed = window.location.hostname;
+    var domainUsed = location.hostname;
 
     // Fix for a bug in FF where the leading dot in the FQDN is not ignored
     if (domainUsed.charAt(0) !== '.' && !ipRegex.test(domainUsed) && domainUsed !== 'localhost')
-        domainUsed = '.' + window.location.hostname;
+        domainUsed = '.' + location.hostname;
 
     document.cookie = 'PREFS=' + cookieData + '; SameSite=Strict; path=/; domain=' +
         domainUsed + '; expires=' + date.toGMTString() + ';';
@@ -280,7 +282,7 @@ player.on('volumechange', function () {
 
 player.on('waiting', function () {
     if (player.playbackRate() > 1 && player.liveTracker.isLive() && player.liveTracker.atLiveEdge()) {
-        console.info('Player has caught up to source, resetting playbackRate.');
+        console.info('Player has caught up to source, resetting playbackRate');
         player.playbackRate(1);
     }
 });
@@ -292,12 +294,12 @@ if (video_data.premiere_timestamp && Math.round(new Date() / 1000) < video_data.
 if (video_data.params.save_player_pos) {
     const url = new URL(location);
     const hasTimeParam = url.searchParams.has('t');
-    const remeberedTime = get_video_time();
+    const rememberedTime = get_video_time();
     let lastUpdated = 0;
 
-    if(!hasTimeParam) set_seconds_after_start(remeberedTime);
+    if(!hasTimeParam) set_seconds_after_start(rememberedTime);
 
-    const updateTime = function () {
+    player.on('timeupdate', function () {
         const raw = player.currentTime();
         const time = Math.floor(raw);
 
@@ -305,9 +307,7 @@ if (video_data.params.save_player_pos) {
             save_video_time(time);
             lastUpdated = time;
         }
-    };
+    });
-
-    player.on('timeupdate', updateTime);
 }
 else remove_all_video_times();
 
@@ -347,53 +347,31 @@ if (!video_data.params.listen && video_data.params.quality === 'dash') {
                         targetQualityLevel = 0;
                         break;
                     default:
-                        const targetHeight = Number.parseInt(video_data.params.quality_dash, 10);
+                        const targetHeight = parseInt(video_data.params.quality_dash);
                         for (let i = 0; i < qualityLevels.length; i++) {
-                            if (qualityLevels[i].height <= targetHeight) {
+                            if (qualityLevels[i].height <= targetHeight)
                                 targetQualityLevel = i;
-                            } else {
+                            else
                                 break;
-                            }
                         }
                 }
-                for (let i = 0; i < qualityLevels.length; i++) {
+                qualityLevels.forEach(function (level, index) {
-                    qualityLevels[i].enabled = (i === targetQualityLevel);
+                    level.enabled = (index === targetQualityLevel);
-                }
+                });
             });
         });
     }
 }
 
 player.vttThumbnails({
-    src: location.origin + '/api/v1/storyboards/' + video_data.id + '?height=90',
+    src: '/api/v1/storyboards/' + video_data.id + '?height=90',
     showTimestamp: true
 });
 
 // Enable annotations
 if (!video_data.params.listen && video_data.params.annotations) {
-    window.addEventListener('load', function (e) {
+    addEventListener('load', function (e) {
-        var video_container = document.getElementById('player');
+        addEventListener('__ar_annotation_click', function (e) {
-        let xhr = new XMLHttpRequest();
-        xhr.responseType = 'text';
-        xhr.timeout = 60000;
-        xhr.open('GET', '/api/v1/annotations/' + video_data.id, true);
-
-        xhr.onreadystatechange = function () {
-            if (xhr.readyState === 4) {
-                if (xhr.status === 200) {
-                    videojs.registerPlugin('youtubeAnnotationsPlugin', youtubeAnnotationsPlugin);
-                    if (!player.paused()) {
-                        player.youtubeAnnotationsPlugin({ annotationXml: xhr.response, videoContainer: video_container });
-                    } else {
-                        player.one('play', function (event) {
-                            player.youtubeAnnotationsPlugin({ annotationXml: xhr.response, videoContainer: video_container });
-                        });
-                    }
-                }
-            }
-        };
-
-        window.addEventListener('__ar_annotation_click', function (e) {
             const url = e.detail.url,
                   target = e.detail.target,
                   seconds = e.detail.seconds;
@@ -406,41 +384,48 @@ if (!video_data.params.listen && video_data.params.annotations) {
             path = path.pathname + path.search;
 
             if (target === 'current') {
-                window.location.href = path;
+                location.href = path;
             } else if (target === 'new') {
-                window.open(path, '_blank');
+                open(path, '_blank');
+            }
+        });
+
+        helpers.xhr('GET', '/api/v1/annotations/' + video_data.id, {
+            responseType: 'text',
+            timeout: 60000
+        }, {
+            on200: function (response) {
+                var video_container = document.getElementById('player');
+                videojs.registerPlugin('youtubeAnnotationsPlugin', youtubeAnnotationsPlugin);
+                if (player.paused()) {
+                    player.one('play', function (event) {
+                        player.youtubeAnnotationsPlugin({ annotationXml: response, videoContainer: video_container });
+                    });
+                } else {
+                    player.youtubeAnnotationsPlugin({ annotationXml: response, videoContainer: video_container });
+                }
             }
         });
 
-        xhr.send();
     });
 }
 
-function increase_volume(delta) {
+function change_volume(delta) {
     const curVolume = player.volume();
     let newVolume = curVolume + delta;
-    if (newVolume > 1) {
+    newVolume = helpers.clamp(newVolume, 0, 1);
-        newVolume = 1;
-    } else if (newVolume < 0) {
-        newVolume = 0;
-    }
     player.volume(newVolume);
 }
 
 function toggle_muted() {
-    const isMuted = player.muted();
+    player.muted(!player.muted());
-    player.muted(!isMuted);
 }
 
 function skip_seconds(delta) {
     const duration = player.duration();
     const curTime = player.currentTime();
     let newTime = curTime + delta;
-    if (newTime > duration) {
+    newTime = helpers.clamp(newTime, 0, duration);
-        newTime = duration;
-    } else if (newTime < 0) {
-        newTime = 0;
-    }
     player.currentTime(newTime);
 }
 
@@ -450,57 +435,21 @@ function set_seconds_after_start(delta) {
 }
 
 function save_video_time(seconds) {
-    const videoId = video_data.id;
     const all_video_times = get_all_video_times();
-
+    all_video_times[video_data.id] = seconds;
-    all_video_times[videoId] = seconds;
+    helpers.storage.set(save_player_pos_key, all_video_times);
-
-    set_all_video_times(all_video_times);
 }
 
 function get_video_time() {
-    try {
+    return get_all_video_times()[video_data.id] || 0;
-        const videoId = video_data.id;
-        const all_video_times = get_all_video_times();
-        const timestamp = all_video_times[videoId];
-
-        return timestamp || 0;
-    }
-    catch (e) {
-        return 0;
-    }
-}
-
-function set_all_video_times(times) {
-    if (storage) {
-        if (times) {
-            try {
-                storage.setItem(save_player_pos_key, JSON.stringify(times));
-            } catch (e) {
-                console.warn('set_all_video_times: ' + e);
-            }
-        } else {
-            storage.removeItem(save_player_pos_key);
-        }
-    }
 }
 
 function get_all_video_times() {
-    if (storage) {
+    return helpers.storage.get(save_player_pos_key) || {};
-        const raw = storage.getItem(save_player_pos_key);
-        if (raw !== null) {
-            try {
-                return JSON.parse(raw);
-            } catch (e) {
-                console.warn('get_all_video_times: ' + e);
-            }
-        }
-    }
-    return {};
 }
 
 function remove_all_video_times() {
-    set_all_video_times(null);
+    helpers.storage.remove(save_player_pos_key);
 }
 
 function set_time_percent(percent) {
@@ -516,21 +465,23 @@ function toggle_play() { player.paused() ? play() : pause(); }
 
 const toggle_captions = (function () {
     let toggledTrack = null;
-    const onChange = function (e) {
+
-        toggledTrack = null;
+    function bindChange(onOrOff) {
-    };
+        player.textTracks()[onOrOff]('change', function (e) {
-    const bindChange = function (onOrOff) {
+            toggledTrack = null;
-        player.textTracks()[onOrOff]('change', onChange);
+        });
-    };
+    }
+
     // Wrapper function to ignore our own emitted events and only listen
     // to events emitted by Video.js on click on the captions menu items.
-    const setMode = function (track, mode) {
+    function setMode(track, mode) {
         bindChange('off');
         track.mode = mode;
-        window.setTimeout(function () {
+        setTimeout(function () {
             bindChange('on');
         }, 0);
-    };
+    }
+
     bindChange('on');
     return function () {
         if (toggledTrack !== null) {
@@ -578,15 +529,11 @@ function increase_playback_rate(steps) {
     const maxIndex = options.playbackRates.length - 1;
     const curIndex = options.playbackRates.indexOf(player.playbackRate());
     let newIndex = curIndex + steps;
-    if (newIndex > maxIndex) {
+    newIndex = helpers.clamp(newIndex, 0, maxIndex);
-        newIndex = maxIndex;
-    } else if (newIndex < 0) {
-        newIndex = 0;
-    }
     player.playbackRate(options.playbackRates[newIndex]);
 }
 
-window.addEventListener('keydown', function (e) {
+addEventListener('keydown', function (e) {
     if (e.target.tagName.toLowerCase() === 'input') {
         // Ignore input when focus is on certain elements, e.g. form fields.
         return;
@@ -619,10 +566,10 @@ window.addEventListener('keydown', function (e) {
         case 'MediaStop':  action = stop; break;
 
         case 'ArrowUp':
-            if (isPlayerFocused) action = increase_volume.bind(this, 0.1);
+            if (isPlayerFocused) action = change_volume.bind(this, 0.1);
             break;
         case 'ArrowDown':
-            if (isPlayerFocused) action = increase_volume.bind(this, -0.1);
+            if (isPlayerFocused) action = change_volume.bind(this, -0.1);
             break;
 
         case 'm':
@@ -673,12 +620,11 @@ window.addEventListener('keydown', function (e) {
             // TODO: Add support to play back previous video.
             break;
 
-        case '.':
+        // TODO: More precise step. Now FPS is taken equal to 29.97
-            // TODO: Add support for next-frame-stepping.
+        // Common FPS: https://forum.videohelp.com/threads/81868#post323588
-            break;
+        // Possible solution is new HTMLVideoElement.requestVideoFrameCallback() https://wicg.github.io/video-rvfc/
-        case ',':
+        case ',': action = function () { pause(); skip_seconds(-1/29.97); }; break;
-            // TODO: Add support for previous-frame-stepping.
+        case '.': action = function () { pause(); skip_seconds( 1/29.97); }; break;
-            break;
 
         case '>': action = increase_playback_rate.bind(this, 1); break;
         case '<': action = increase_playback_rate.bind(this, -1); break;
@@ -697,10 +643,6 @@ window.addEventListener('keydown', function (e) {
 // Add support for controlling the player volume by scrolling over it. Adapted from
 // https://github.com/ctd1500/videojs-hotkeys/blob/bb4a158b2e214ccab87c2e7b95f42bc45c6bfd87/videojs.hotkeys.js#L292-L328
 (function () {
-    const volumeStep = 0.05;
-    const enableVolumeScroll = true;
-    const enableHoverScroll = true;
-    const doc = document;
     const pEl = document.getElementById('player');
 
     var volumeHover = false;
@@ -710,39 +652,23 @@ window.addEventListener('keydown', function (e) {
         volumeSelector.onmouseout = function () { volumeHover = false; };
     }
 
-    var mouseScroll = function mouseScroll(event) {
+    function mouseScroll(event) {
-        var activeEl = doc.activeElement;
-        if (enableHoverScroll) {
-            // If we leave this undefined then it can match non-existent elements below
-            activeEl = 0;
-        }
-
         // When controls are disabled, hotkeys will be disabled as well
-        if (player.controls()) {
+        if (!player.controls() || !volumeHover) return;
-            if (volumeHover) {
-                if (enableVolumeScroll) {
-                    event = window.event || event;
-                    var delta = Math.max(-1, Math.min(1, (event.wheelDelta || -event.detail)));
-                    event.preventDefault();
 
-                    if (delta === 1) {
+        event.preventDefault();
-                        increase_volume(volumeStep);
+        var wheelMove = event.wheelDelta || -event.detail;
-                    } else if (delta === -1) {
+        var volumeSign = Math.sign(wheelMove);
-                        increase_volume(-volumeStep);
+
-                    }
+        change_volume(volumeSign * 0.05); // decrease/increase by 5%
-                }
+    }
-            }
-        }
-    };
 
     player.on('mousewheel', mouseScroll);
     player.on('DOMMouseScroll', mouseScroll);
 }());
 
 // Since videojs-share can sometimes be blocked, we defer it until last
-if (player.share) {
+if (player.share) player.share(shareOptions);
-    player.share(shareOptions);
-}
 
 // show the preferred caption by default
 if (player_data.preferred_caption_found) {
@@ -763,7 +689,7 @@ if (navigator.vendor === 'Apple Computer, Inc.' && video_data.params.listen) {
 }
 
 // Watch on Invidious link
-if (window.location.pathname.startsWith('/embed/')) {
+if (location.pathname.startsWith('/embed/')) {
     const Button = videojs.getComponent('Button');
     let watch_on_invidious_button = new Button(player);
 
@@ -778,3 +704,11 @@ if (window.location.pathname.startsWith('/embed/')) {
     var cb = player.getChild('ControlBar');
     cb.addChild(watch_on_invidious_button);
 }
+
+addEventListener('DOMContentLoaded', function () {
+    // Save time during redirection on another instance
+    const changeInstanceLink = document.querySelector('#watch-on-another-invidious-instance > a');
+    if (changeInstanceLink) changeInstanceLink.addEventListener('click', function () {
+        changeInstanceLink.href = addCurrentTimeToURL(changeInstanceLink.href);
+    });
+});

assets/js/playlist_widget.js

@@ -1,5 +1,6 @@
 'use strict';
 var playlist_data = JSON.parse(document.getElementById('playlist_data').textContent);
+var payload = 'csrf_token=' + playlist_data.csrf_token;
 
 function add_playlist_video(target) {
     var select = target.parentNode.children[0].children[1];
@@ -8,21 +9,12 @@ function add_playlist_video(target) {
     var url = '/playlist_ajax?action_add_video=1&redirect=false' +
         '&video_id=' + target.getAttribute('data-id') +
         '&playlist_id=' + option.getAttribute('data-plid');
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('POST', url, {payload: payload}, {
-        if (xhr.readyState === 4) {
+        on200: function (response) {
-            if (xhr.status === 200) {
+            option.textContent = '✓' + option.textContent;
-                option.innerText = '✓' + option.innerText;
-            }
         }
-    };
+    });
-
-    xhr.send('csrf_token=' + playlist_data.csrf_token);
 }
 
 function add_playlist_item(target) {
@@ -32,21 +24,12 @@ function add_playlist_item(target) {
     var url = '/playlist_ajax?action_add_video=1&redirect=false' +
         '&video_id=' + target.getAttribute('data-id') +
         '&playlist_id=' + target.getAttribute('data-plid');
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('POST', url, {payload: payload}, {
-        if (xhr.readyState === 4) {
+        onNon200: function (xhr) {
-            if (xhr.status !== 200) {
+            tile.style.display = '';
-                tile.style.display = '';
-            }
         }
-    };
+    });
-
-    xhr.send('csrf_token=' + playlist_data.csrf_token);
 }
 
 function remove_playlist_item(target) {
@@ -56,19 +39,10 @@ function remove_playlist_item(target) {
     var url = '/playlist_ajax?action_remove_video=1&redirect=false' +
         '&set_video_id=' + target.getAttribute('data-index') +
         '&playlist_id=' + target.getAttribute('data-plid');
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('POST', url, {payload: payload}, {
-        if (xhr.readyState === 4) {
+        onNon200: function (xhr) {
-            if (xhr.status !== 200) {
+            tile.style.display = '';
-                tile.style.display = '';
-            }
         }
-    };
+    });
-
-    xhr.send('csrf_token=' + playlist_data.csrf_token);
 }

assets/js/subscribe_widget.js

@@ -1,8 +1,9 @@
 'use strict';
 var subscribe_data = JSON.parse(document.getElementById('subscribe_data').textContent);
+var payload = 'csrf_token=' + subscribe_data.csrf_token;
 
 var subscribe_button = document.getElementById('subscribe');
-subscribe_button.parentNode['action'] = 'javascript:void(0)';
+subscribe_button.parentNode.action = 'javascript:void(0)';
 
 if (subscribe_button.getAttribute('data-type') === 'subscribe') {
     subscribe_button.onclick = subscribe;
@@ -10,87 +11,34 @@ if (subscribe_button.getAttribute('data-type') === 'subscribe') {
     subscribe_button.onclick = unsubscribe;
 }
 
-function subscribe(retries) {
+function subscribe() {
-    if (retries === undefined) retries = 5;
-
-    if (retries <= 0) {
-        console.warn('Failed to subscribe.');
-        return;
-    }
-
-    var url = '/subscription_ajax?action_create_subscription_to_channel=1&redirect=false' +
-        '&c=' + subscribe_data.ucid;
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
-
     var fallback = subscribe_button.innerHTML;
     subscribe_button.onclick = unsubscribe;
     subscribe_button.innerHTML = '<b>' + subscribe_data.unsubscribe_text + ' | ' + subscribe_data.sub_count_text + '</b>';
 
-    xhr.onreadystatechange = function () {
+    var url = '/subscription_ajax?action_create_subscription_to_channel=1&redirect=false' +
-        if (xhr.readyState === 4) {
+        '&c=' + subscribe_data.ucid;
-            if (xhr.status !== 200) {
+
-                subscribe_button.onclick = subscribe;
+    helpers.xhr('POST', url, {payload: payload, retries: 5, entity_name: 'subscribe request'}, {
-                subscribe_button.innerHTML = fallback;
+        onNon200: function (xhr) {
-            }
+            subscribe_button.onclick = subscribe;
+            subscribe_button.innerHTML = fallback;
         }
-    };
+    });
-
-    xhr.onerror = function () {
-        console.warn('Subscribing failed... ' + retries + '/5');
-        setTimeout(function () { subscribe(retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        console.warn('Subscribing failed... ' + retries + '/5');
-        subscribe(retries - 1);
-    };
-
-    xhr.send('csrf_token=' + subscribe_data.csrf_token);
 }
 
-function unsubscribe(retries) {
+function unsubscribe() {
-    if (retries === undefined)
-        retries = 5;
-
-    if (retries <= 0) {
-        console.warn('Failed to subscribe');
-        return;
-    }
-
-    var url = '/subscription_ajax?action_remove_subscriptions=1&redirect=false' +
-        '&c=' + subscribe_data.ucid;
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
-
     var fallback = subscribe_button.innerHTML;
     subscribe_button.onclick = subscribe;
     subscribe_button.innerHTML = '<b>' + subscribe_data.subscribe_text + ' | ' + subscribe_data.sub_count_text + '</b>';
 
-    xhr.onreadystatechange = function () {
+    var url = '/subscription_ajax?action_remove_subscriptions=1&redirect=false' +
-        if (xhr.readyState === 4) {
+        '&c=' + subscribe_data.ucid;
-            if (xhr.status !== 200) {
+
-                subscribe_button.onclick = unsubscribe;
+    helpers.xhr('POST', url, {payload: payload, retries: 5, entity_name: 'unsubscribe request'}, {
-                subscribe_button.innerHTML = fallback;
+        onNon200: function (xhr) {
-            }
+            subscribe_button.onclick = unsubscribe;
+            subscribe_button.innerHTML = fallback;
         }
-    };
+    });
-
-    xhr.onerror = function () {
-        console.warn('Unsubscribing failed... ' + retries + '/5');
-        setTimeout(function () { unsubscribe(retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        console.warn('Unsubscribing failed... ' + retries + '/5');
-        unsubscribe(retries - 1);
-    };
-
-    xhr.send('csrf_token=' + subscribe_data.csrf_token);
 }

assets/js/themes.js

@@ -1,90 +1,44 @@
 'use strict';
 var toggle_theme = document.getElementById('toggle_theme');
-toggle_theme.href = 'javascript:void(0);';
+toggle_theme.href = 'javascript:void(0)';
 
+const STORAGE_KEY_THEME = 'dark_mode';
+const THEME_DARK = 'dark';
+const THEME_LIGHT = 'light';
+
+// TODO: theme state controlled by system
 toggle_theme.addEventListener('click', function () {
-    var dark_mode = document.body.classList.contains('light-theme');
+    const isDarkTheme = helpers.storage.get(STORAGE_KEY_THEME) === THEME_DARK;
-
+    const newTheme = isDarkTheme ? THEME_LIGHT : THEME_DARK;
-    var url = '/toggle_theme?redirect=false';
+    setTheme(newTheme);
-    var xhr = new XMLHttpRequest();
+    helpers.storage.set(STORAGE_KEY_THEME, newTheme);
-    xhr.responseType = 'json';
+    helpers.xhr('GET', '/toggle_theme?redirect=false', {}, {});
-    xhr.timeout = 10000;
-    xhr.open('GET', url, true);
-
-    set_mode(dark_mode);
-    try {
-        window.localStorage.setItem('dark_mode', dark_mode ? 'dark' : 'light');
-    } catch (e) {}
-
-    xhr.send();
 });
 
-window.addEventListener('storage', function (e) {
+/** @param {THEME_DARK|THEME_LIGHT} theme */
-    if (e.key === 'dark_mode') {
+function setTheme(theme) {
-        update_mode(e.newValue);
+    // By default body element has .no-theme class that uses OS theme via CSS @media rules
-    }
+    // It rewrites using hard className below
-});
+    if (theme === THEME_DARK) {
-
+        toggle_theme.children[0].className = 'icon ion-ios-sunny';
-window.addEventListener('DOMContentLoaded', function () {
+        document.body.className = 'dark-theme';
-    const dark_mode = document.getElementById('dark_mode_pref').textContent;
-    try {
-        // Update localStorage if dark mode preference changed on preferences page
-        window.localStorage.setItem('dark_mode', dark_mode);
-    } catch (e) {}
-    update_mode(dark_mode);
-});
-
-
-var darkScheme = window.matchMedia('(prefers-color-scheme: dark)');
-var lightScheme = window.matchMedia('(prefers-color-scheme: light)');
-
-darkScheme.addListener(scheme_switch);
-lightScheme.addListener(scheme_switch);
-
-function scheme_switch (e) {
-  // ignore this method if we have a preference set
-  try {
-    if (localStorage.getItem('dark_mode')) {
-      return;
-    }
-  } catch (exception) {}
-  if (e.matches) {
-    if (e.media.includes('dark')) {
-      set_mode(true);
-    } else if (e.media.includes('light')) {
-      set_mode(false);
-    }
-  }
-}
-
-function set_mode (bool) {
-    if (bool) {
-        // dark
-        toggle_theme.children[0].setAttribute('class', 'icon ion-ios-sunny');
-        document.body.classList.remove('no-theme');
-        document.body.classList.remove('light-theme');
-        document.body.classList.add('dark-theme');
     } else {
-        // light
+        toggle_theme.children[0].className = 'icon ion-ios-moon';
-        toggle_theme.children[0].setAttribute('class', 'icon ion-ios-moon');
+        document.body.className = 'light-theme';
-        document.body.classList.remove('no-theme');
-        document.body.classList.remove('dark-theme');
-        document.body.classList.add('light-theme');
     }
 }
 
-function update_mode (mode) {
+// Handles theme change event caused by other tab
-    if (mode === 'true' /* for backwards compatibility */ || mode === 'dark') {
+addEventListener('storage', function (e) {
-        // If preference for dark mode indicated
+    if (e.key === STORAGE_KEY_THEME)
-        set_mode(true);
+        setTheme(helpers.storage.get(STORAGE_KEY_THEME));
+});
+
+// Set theme from preferences on page load
+addEventListener('DOMContentLoaded', function () {
+    const prefTheme = document.getElementById('dark_mode_pref').textContent;
+    if (prefTheme) {
+        setTheme(prefTheme);
+        helpers.storage.set(STORAGE_KEY_THEME, prefTheme);
     }
-    else if (mode === 'false' /* for backwards compatibility */ || mode === 'light') {
+});
-        // If preference for light mode indicated
-        set_mode(false);
-    }
-    else if (document.getElementById('dark_mode_pref').textContent === '' && window.matchMedia('(prefers-color-scheme: dark)').matches) {
-        // If no preference indicated here and no preference indicated on the preferences page (backend), but the browser tells us that the operating system has a dark theme
-        set_mode(true);
-    }
-    // else do nothing, falling back to the mode defined by the `dark_mode` preference on the preferences page (backend)
-}

assets/js/watch.js

@@ -1,5 +1,7 @@
 'use strict';
 var video_data = JSON.parse(document.getElementById('video_data').textContent);
+var spinnerHTML = '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3>';
+var spinnerHTMLwithHR = spinnerHTML + '<hr>';
 
 String.prototype.supplant = function (o) {
     return this.replace(/{([^{}]*)}/g, function (a, b) {
@@ -10,24 +12,24 @@ String.prototype.supplant = function (o) {
 
 function toggle_parent(target) {
     var body = target.parentNode.parentNode.children[1];
-    if (body.style.display === null || body.style.display === '') {
+    if (body.style.display === 'none') {
-        target.textContent = '[ + ]';
-        body.style.display = 'none';
-    } else {
         target.textContent = '[ − ]';
         body.style.display = '';
+    } else {
+        target.textContent = '[ + ]';
+        body.style.display = 'none';
     }
 }
 
 function toggle_comments(event) {
     var target = event.target;
     var body = target.parentNode.parentNode.parentNode.children[1];
-    if (body.style.display === null || body.style.display === '') {
+    if (body.style.display === 'none') {
-        target.textContent = '[ + ]';
-        body.style.display = 'none';
-    } else {
         target.textContent = '[ − ]';
         body.style.display = '';
+    } else {
+        target.textContent = '[ + ]';
+        body.style.display = 'none';
     }
 }
 
@@ -79,56 +81,31 @@ if (continue_button) {
 function next_video() {
     var url = new URL('https://example.com/watch?v=' + video_data.next_video);
 
-    if (video_data.params.autoplay || video_data.params.continue_autoplay) {
+    if (video_data.params.autoplay || video_data.params.continue_autoplay)
         url.searchParams.set('autoplay', '1');
-    }
+    if (video_data.params.listen !== video_data.preferences.listen)
-
-    if (video_data.params.listen !== video_data.preferences.listen) {
         url.searchParams.set('listen', video_data.params.listen);
-    }
+    if (video_data.params.speed !== video_data.preferences.speed)
-
-    if (video_data.params.speed !== video_data.preferences.speed) {
         url.searchParams.set('speed', video_data.params.speed);
-    }
+    if (video_data.params.local !== video_data.preferences.local)
-
-    if (video_data.params.local !== video_data.preferences.local) {
         url.searchParams.set('local', video_data.params.local);
-    }
-
     url.searchParams.set('continue', '1');
+
     location.assign(url.pathname + url.search);
 }
 
 function continue_autoplay(event) {
     if (event.target.checked) {
-        player.on('ended', function () {
+        player.on('ended', next_video);
-            next_video();
-        });
     } else {
         player.off('ended');
     }
 }
 
-function number_with_separator(val) {
+function get_playlist(plid) {
-    while (/(\d+)(\d{3})/.test(val.toString())) {
-        val = val.toString().replace(/(\d+)(\d{3})/, '$1' + ',' + '$2');
-    }
-    return val;
-}
-
-function get_playlist(plid, retries) {
-    if (retries === undefined) retries = 5;
     var playlist = document.getElementById('playlist');
 
-    if (retries <= 0) {
+    playlist.innerHTML = spinnerHTMLwithHR;
-        console.warn('Failed to pull playlist');
-        playlist.innerHTML = '';
-        return;
-    }
-
-    playlist.innerHTML = ' \
-        <h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3> \
-        <hr>';
 
     var plid_url;
     if (plid.startsWith('RD')) {
@@ -142,225 +119,148 @@ function get_playlist(plid, retries) {
             '&format=html&hl=' + video_data.preferences.locale;
     }
 
-    var xhr = new XMLHttpRequest();
+    helpers.xhr('GET', plid_url, {retries: 5, entity_name: 'playlist'}, {
-    xhr.responseType = 'json';
+        on200: function (response) {
-    xhr.timeout = 10000;
+            playlist.innerHTML = response.playlistHtml;
-    xhr.open('GET', plid_url, true);
 
-    xhr.onreadystatechange = function () {
+            if (!response.nextVideo) return;
-        if (xhr.readyState === 4) {
-            if (xhr.status === 200) {
-                playlist.innerHTML = xhr.response.playlistHtml;
-                var nextVideo = document.getElementById(xhr.response.nextVideo);
-                nextVideo.parentNode.parentNode.scrollTop = nextVideo.offsetTop;
 
-                if (xhr.response.nextVideo) {
+            var nextVideo = document.getElementById(response.nextVideo);
-                    player.on('ended', function () {
+            nextVideo.parentNode.parentNode.scrollTop = nextVideo.offsetTop;
-                        var url = new URL('https://example.com/watch?v=' + xhr.response.nextVideo);
 
-                        url.searchParams.set('list', plid);
+            player.on('ended', function () {
-                        if (!plid.startsWith('RD')) {
+                var url = new URL('https://example.com/watch?v=' + response.nextVideo);
-                            url.searchParams.set('index', xhr.response.index);
-                        }
 
-                        if (video_data.params.autoplay || video_data.params.continue_autoplay) {
+                url.searchParams.set('list', plid);
-                            url.searchParams.set('autoplay', '1');
+                if (!plid.startsWith('RD'))
-                        }
+                    url.searchParams.set('index', response.index);
+                if (video_data.params.autoplay || video_data.params.continue_autoplay)
+                    url.searchParams.set('autoplay', '1');
+                if (video_data.params.listen !== video_data.preferences.listen)
+                    url.searchParams.set('listen', video_data.params.listen);
+                if (video_data.params.speed !== video_data.preferences.speed)
+                    url.searchParams.set('speed', video_data.params.speed);
+                if (video_data.params.local !== video_data.preferences.local)
+                    url.searchParams.set('local', video_data.params.local);
 
-                        if (video_data.params.listen !== video_data.preferences.listen) {
+                location.assign(url.pathname + url.search);
-                            url.searchParams.set('listen', video_data.params.listen);
+            });
-                        }
+        },
-
+        onNon200: function (xhr) {
-                        if (video_data.params.speed !== video_data.preferences.speed) {
+            playlist.innerHTML = '';
-                            url.searchParams.set('speed', video_data.params.speed);
+            document.getElementById('continue').style.display = '';
-                        }
+        },
-
+        onError: function (xhr) {
-                        if (video_data.params.local !== video_data.preferences.local) {
+            playlist.innerHTML = spinnerHTMLwithHR;
-                            url.searchParams.set('local', video_data.params.local);
+        },
-                        }
+        onTimeout: function (xhr) {
-
+            playlist.innerHTML = spinnerHTMLwithHR;
-                        location.assign(url.pathname + url.search);
-                    });
-                }
-            } else {
-                playlist.innerHTML = '';
-                document.getElementById('continue').style.display = '';
-            }
         }
-    };
+    });
-
-    xhr.onerror = function () {
-        playlist = document.getElementById('playlist');
-        playlist.innerHTML =
-            '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3><hr>';
-
-        console.warn('Pulling playlist timed out... ' + retries + '/5');
-        setTimeout(function () { get_playlist(plid, retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        playlist = document.getElementById('playlist');
-        playlist.innerHTML =
-            '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3><hr>';
-
-        console.warn('Pulling playlist timed out... ' + retries + '/5');
-        get_playlist(plid, retries - 1);
-    };
-
-    xhr.send();
 }
 
-function get_reddit_comments(retries) {
+function get_reddit_comments() {
-    if (retries === undefined) retries = 5;
     var comments = document.getElementById('comments');
 
-    if (retries <= 0) {
-        console.warn('Failed to pull comments');
-        comments.innerHTML = '';
-        return;
-    }
-
     var fallback = comments.innerHTML;
-    comments.innerHTML =
+    comments.innerHTML = spinnerHTML;
-        '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3>';
 
     var url = '/api/v1/comments/' + video_data.id +
         '?source=reddit&format=html' +
         '&hl=' + video_data.preferences.locale;
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('GET', url, true);
 
-    xhr.onreadystatechange = function () {
+    var onNon200 = function (xhr) { comments.innerHTML = fallback; };
-        if (xhr.readyState === 4) {
+    if (video_data.params.comments[1] === 'youtube')
-            if (xhr.status === 200) {
+        onNon200 = function (xhr) {};
-                comments.innerHTML = ' \
+
-                <div> \
+    helpers.xhr('GET', url, {retries: 5, entity_name: ''}, {
-                    <h3> \
+        on200: function (response) {
-                        <a href="javascript:void(0)">[ − ]</a> \
+            comments.innerHTML = ' \
-                        {title} \
+            <div> \
-                    </h3> \
+                <h3> \
-                    <p> \
+                    <a href="javascript:void(0)">[ − ]</a> \
-                        <b> \
+                    {title} \
-                            <a href="javascript:void(0)" data-comments="youtube"> \
+                </h3> \
-                                {youtubeCommentsText} \
+                <p> \
-                            </a> \
-                        </b> \
-                    </p> \
                     <b> \
-                        <a rel="noopener" target="_blank" href="https://reddit.com{permalink}">{redditPermalinkText}</a> \
+                        <a href="javascript:void(0)" data-comments="youtube"> \
+                            {youtubeCommentsText} \
+                        </a> \
                     </b> \
-                </div> \
+                </p> \
-                <div>{contentHtml}</div> \
+                <b> \
-                <hr>'.supplant({
+                    <a rel="noopener" target="_blank" href="https://reddit.com{permalink}">{redditPermalinkText}</a> \
-                    title: xhr.response.title,
+                </b> \
-                    youtubeCommentsText: video_data.youtube_comments_text,
+            </div> \
-                    redditPermalinkText: video_data.reddit_permalink_text,
+            <div>{contentHtml}</div> \
-                    permalink: xhr.response.permalink,
+            <hr>'.supplant({
-                    contentHtml: xhr.response.contentHtml
+                title: response.title,
-                });
+                youtubeCommentsText: video_data.youtube_comments_text,
+                redditPermalinkText: video_data.reddit_permalink_text,
+                permalink: response.permalink,
+                contentHtml: response.contentHtml
+            });
 
-                comments.children[0].children[0].children[0].onclick = toggle_comments;
+            comments.children[0].children[0].children[0].onclick = toggle_comments;
-                comments.children[0].children[1].children[0].onclick = swap_comments;
+            comments.children[0].children[1].children[0].onclick = swap_comments;
-            } else {
+        },
-                if (video_data.params.comments[1] === 'youtube') {
+        onNon200: onNon200, // declared above
-                    console.warn('Pulling comments failed... ' + retries + '/5');
+    });
-                    setTimeout(function () { get_youtube_comments(retries - 1); }, 1000);
-                } else {
-                    comments.innerHTML = fallback;
-                }
-            }
-        }
-    };
-
-    xhr.onerror = function () {
-        console.warn('Pulling comments failed... ' + retries + '/5');
-        setTimeout(function () { get_reddit_comments(retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        console.warn('Pulling comments failed... ' + retries + '/5');
-        get_reddit_comments(retries - 1);
-    };
-
-    xhr.send();
 }
 
-function get_youtube_comments(retries) {
+function get_youtube_comments() {
-    if (retries === undefined) retries = 5;
     var comments = document.getElementById('comments');
 
-    if (retries <= 0) {
-        console.warn('Failed to pull comments');
-        comments.innerHTML = '';
-        return;
-    }
-
     var fallback = comments.innerHTML;
-    comments.innerHTML =
+    comments.innerHTML = spinnerHTML;
-        '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3>';
 
     var url = '/api/v1/comments/' + video_data.id +
         '?format=html' +
         '&hl=' + video_data.preferences.locale +
         '&thin_mode=' + video_data.preferences.thin_mode;
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('GET', url, true);
 
-    xhr.onreadystatechange = function () {
+    var onNon200 = function (xhr) { comments.innerHTML = fallback; };
-        if (xhr.readyState === 4) {
+    if (video_data.params.comments[1] === 'youtube')
-            if (xhr.status === 200) {
+        onNon200 = function (xhr) {};
-                comments.innerHTML = ' \
-                <div> \
-                    <h3> \
-                        <a href="javascript:void(0)">[ − ]</a> \
-                        {commentsText}  \
-                    </h3> \
-                    <b> \
-                        <a href="javascript:void(0)" data-comments="reddit"> \
-                            {redditComments} \
-                        </a> \
-                    </b> \
-                </div> \
-                <div>{contentHtml}</div> \
-                <hr>'.supplant({
-                    contentHtml: xhr.response.contentHtml,
-                    redditComments: video_data.reddit_comments_text,
-                    commentsText: video_data.comments_text.supplant(
-                        { commentCount: number_with_separator(xhr.response.commentCount) }
-                    )
-                });
 
-                comments.children[0].children[0].children[0].onclick = toggle_comments;
+    helpers.xhr('GET', url, {retries: 5, entity_name: 'comments'}, {
-                comments.children[0].children[1].children[0].onclick = swap_comments;
+        on200: function (response) {
-            } else {
+            comments.innerHTML = ' \
-                if (video_data.params.comments[1] === 'youtube') {
+            <div> \
-                    setTimeout(function () { get_youtube_comments(retries - 1); }, 1000);
+                <h3> \
-                } else {
+                    <a href="javascript:void(0)">[ − ]</a> \
-                    comments.innerHTML = '';
+                    {commentsText}  \
-                }
+                </h3> \
-            }
+                <b> \
+                    <a href="javascript:void(0)" data-comments="reddit"> \
+                        {redditComments} \
+                    </a> \
+                </b> \
+            </div> \
+            <div>{contentHtml}</div> \
+            <hr>'.supplant({
+                contentHtml: response.contentHtml,
+                redditComments: video_data.reddit_comments_text,
+                commentsText: video_data.comments_text.supplant({
+                    // toLocaleString correctly splits number with local thousands separator. e.g.:
+                    // '1,234,567.89' for user with English locale
+                    // '1 234 567,89' for user with Russian locale
+                    // '1.234.567,89' for user with Portuguese locale
+                    commentCount: response.commentCount.toLocaleString()
+                })
+            });
+
+            comments.children[0].children[0].children[0].onclick = toggle_comments;
+            comments.children[0].children[1].children[0].onclick = swap_comments;
+        },
+        onNon200: onNon200, // declared above
+        onError: function (xhr) {
+            comments.innerHTML = spinnerHTML;
+        },
+        onTimeout: function (xhr) {
+            comments.innerHTML = spinnerHTML;
         }
-    };
+    });
-
-    xhr.onerror = function () {
-        comments.innerHTML =
-            '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3>';
-        console.warn('Pulling comments failed... ' + retries + '/5');
-        setTimeout(function () { get_youtube_comments(retries - 1); }, 1000);
-    };
-
-    xhr.ontimeout = function () {
-        comments.innerHTML =
-            '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3>';
-        console.warn('Pulling comments failed... ' + retries + '/5');
-        get_youtube_comments(retries - 1);
-    };
-
-    xhr.send();
 }
 
 function get_youtube_replies(target, load_more, load_replies) {
@@ -368,91 +268,72 @@ function get_youtube_replies(target, load_more, load_replies) {
 
     var body = target.parentNode.parentNode;
     var fallback = body.innerHTML;
-    body.innerHTML =
+    body.innerHTML = spinnerHTML;
-        '<h3 style="text-align:center"><div class="loading"><i class="icon ion-ios-refresh"></i></div></h3>';
 
     var url = '/api/v1/comments/' + video_data.id +
         '?format=html' +
         '&hl=' + video_data.preferences.locale +
         '&thin_mode=' + video_data.preferences.thin_mode +
         '&continuation=' + continuation;
-    if (load_replies) {
+    if (load_replies) url += '&action=action_get_comment_replies';
-        url += '&action=action_get_comment_replies';
-    }
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('GET', url, true);
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('GET', url, {}, {
-        if (xhr.readyState === 4) {
+        on200: function (response) {
-            if (xhr.status === 200) {
+            if (load_more) {
-                if (load_more) {
+                body = body.parentNode.parentNode;
-                    body = body.parentNode.parentNode;
+                body.removeChild(body.lastElementChild);
-                    body.removeChild(body.lastElementChild);
+                body.innerHTML += response.contentHtml;
-                    body.innerHTML += xhr.response.contentHtml;
-                } else {
-                    body.removeChild(body.lastElementChild);
-
-                    var p = document.createElement('p');
-                    var a = document.createElement('a');
-                    p.appendChild(a);
-
-                    a.href = 'javascript:void(0)';
-                    a.onclick = hide_youtube_replies;
-                    a.setAttribute('data-sub-text', video_data.hide_replies_text);
-                    a.setAttribute('data-inner-text', video_data.show_replies_text);
-                    a.innerText = video_data.hide_replies_text;
-
-                    var div = document.createElement('div');
-                    div.innerHTML = xhr.response.contentHtml;
-
-                    body.appendChild(p);
-                    body.appendChild(div);
-                }
             } else {
-                body.innerHTML = fallback;
+                body.removeChild(body.lastElementChild);
+
+                var p = document.createElement('p');
+                var a = document.createElement('a');
+                p.appendChild(a);
+
+                a.href = 'javascript:void(0)';
+                a.onclick = hide_youtube_replies;
+                a.setAttribute('data-sub-text', video_data.hide_replies_text);
+                a.setAttribute('data-inner-text', video_data.show_replies_text);
+                a.textContent = video_data.hide_replies_text;
+
+                var div = document.createElement('div');
+                div.innerHTML = response.contentHtml;
+
+                body.appendChild(p);
+                body.appendChild(div);
             }
+        },
+        onNon200: function (xhr) {
+            body.innerHTML = fallback;
+        },
+        onTimeout: function (xhr) {
+            console.warn('Pulling comments failed');
+            body.innerHTML = fallback;
         }
-    };
+    });
-
-    xhr.ontimeout = function () {
-        console.warn('Pulling comments failed.');
-        body.innerHTML = fallback;
-    };
-
-    xhr.send();
 }
 
 if (video_data.play_next) {
     player.on('ended', function () {
         var url = new URL('https://example.com/watch?v=' + video_data.next_video);
 
-        if (video_data.params.autoplay || video_data.params.continue_autoplay) {
+        if (video_data.params.autoplay || video_data.params.continue_autoplay)
             url.searchParams.set('autoplay', '1');
-        }
+        if (video_data.params.listen !== video_data.preferences.listen)
-
-        if (video_data.params.listen !== video_data.preferences.listen) {
             url.searchParams.set('listen', video_data.params.listen);
-        }
+        if (video_data.params.speed !== video_data.preferences.speed)
-
-        if (video_data.params.speed !== video_data.preferences.speed) {
             url.searchParams.set('speed', video_data.params.speed);
-        }
+        if (video_data.params.local !== video_data.preferences.local)
-
-        if (video_data.params.local !== video_data.preferences.local) {
             url.searchParams.set('local', video_data.params.local);
-        }
-
         url.searchParams.set('continue', '1');
+
         location.assign(url.pathname + url.search);
     });
 }
 
-window.addEventListener('load', function (e) {
+addEventListener('load', function (e) {
-    if (video_data.plid) {
+    if (video_data.plid)
         get_playlist(video_data.plid);
-    }
 
     if (video_data.params.comments[0] === 'youtube') {
         get_youtube_comments();

assets/js/watched_widget.js

@@ -1,5 +1,6 @@
 'use strict';
 var watched_data = JSON.parse(document.getElementById('watched_data').textContent);
+var payload = 'csrf_token=' + watched_data.csrf_token;
 
 function mark_watched(target) {
     var tile = target.parentNode.parentNode.parentNode.parentNode.parentNode;
@@ -7,45 +8,27 @@ function mark_watched(target) {
 
     var url = '/watch_ajax?action_mark_watched=1&redirect=false' +
         '&id=' + target.getAttribute('data-id');
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('POST', url, {payload: payload}, {
-        if (xhr.readyState === 4) {
+        onNon200: function (xhr) {
-            if (xhr.status !== 200) {
+            tile.style.display = '';
-                tile.style.display = '';
-            }
         }
-    };
+    });
-
-    xhr.send('csrf_token=' + watched_data.csrf_token);
 }
 
 function mark_unwatched(target) {
     var tile = target.parentNode.parentNode.parentNode.parentNode.parentNode;
     tile.style.display = 'none';
     var count = document.getElementById('count');
-    count.innerText = count.innerText - 1;
+    count.textContent--;
 
     var url = '/watch_ajax?action_mark_unwatched=1&redirect=false' +
         '&id=' + target.getAttribute('data-id');
-    var xhr = new XMLHttpRequest();
-    xhr.responseType = 'json';
-    xhr.timeout = 10000;
-    xhr.open('POST', url, true);
-    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 
-    xhr.onreadystatechange = function () {
+    helpers.xhr('POST', url, {payload: payload}, {
-        if (xhr.readyState === 4) {
+        onNon200: function (xhr) {
-            if (xhr.status !== 200) {
+            count.textContent++;
-                count.innerText = count.innerText - 1 + 2;
+            tile.style.display = '';
-                tile.style.display = '';
-            }
         }
-    };
+    });
-
-    xhr.send('csrf_token=' + watched_data.csrf_token);
 }

src/invidious/comments.cr

@@ -481,7 +481,7 @@ def template_reddit_comments(root, locale)
 
         html << <<-END_HTML
         <p>
-          <a href="javascript:void(0)" data-onclick="toggle_parent">[ - ]</a>
+          <a href="javascript:void(0)" data-onclick="toggle_parent">[ − ]</a>
           <b><a href="https://www.reddit.com/user/#{child.author}">#{child.author}</a></b>
           #{translate_count(locale, "comments_points_count", child.score, NumberFormatting::Separator)}
           <span title="#{child.created_utc.to_s(translate(locale, "%a %B %-d %T %Y UTC"))}">#{translate(locale, "`x` ago", recode_date(child.created_utc, locale))}</span>

src/invidious/views/licenses.ecr

@@ -9,6 +9,20 @@
 <body>
     <h1><%= translate(locale, "JavaScript license information") %></h1>
     <table id="jslicense-labels1">
+        <tr>
+            <td>
+                <a href="/js/_helpers.js?v=<%= ASSET_COMMIT %>">_helpers.js</a>
+            </td>
+
+            <td>
+                <a href="https://www.gnu.org/licenses/agpl-3.0.html">AGPL-3.0</a>
+            </td>
+
+            <td>
+                <a href="/js/_helpers.js?v=<%= ASSET_COMMIT %>"><%= translate(locale, "source") %></a>
+            </td>
+        </tr>
+
         <tr>
             <td>
                 <a href="/js/community.js?v=<%= ASSET_COMMIT %>">community.js</a>

src/invidious/views/template.ecr

@@ -17,6 +17,7 @@
     <link rel="stylesheet" href="/css/grids-responsive-min.css?v=<%= ASSET_COMMIT %>">
     <link rel="stylesheet" href="/css/ionicons.min.css?v=<%= ASSET_COMMIT %>">
     <link rel="stylesheet" href="/css/default.css?v=<%= ASSET_COMMIT %>">
+    <script src="/js/_helpers.js?v=<%= ASSET_COMMIT %>"></script>
 </head>
 
 <%

src/invidious/views/watch.ecr

@@ -278,24 +278,24 @@ we're going to need to do it here in order to allow for translations.
                                     </div>
                                 <% end %>
                                 <p style="width:100%"><%= rv["title"] %></p>
-                                <h5 class="pure-g">
-                                    <div class="pure-u-14-24">
-                                        <% if rv["ucid"]? %>
-                                            <b style="width:100%"><a href="/channel/<%= rv["ucid"] %>"><%= rv["author"]? %><% if rv["author_verified"]? == "true" %>&nbsp;<i class="icon ion ion-md-checkmark-circle"></i><% end %></a></b>
-                                        <% else %>
-                                            <b style="width:100%"><%= rv["author"]? %><% if rv["author_verified"]? == "true" %>&nbsp;<i class="icon ion ion-md-checkmark-circle"></i><% end %></b>
-                                        <% end %>
-                                    </div>
-
-                                    <div class="pure-u-10-24" style="text-align:right">
-                                        <b class="width:100%"><%=
-                                            views = rv["view_count"]?.try &.to_i?
-                                            views ||= rv["view_count_short"]?.try { |x| short_text_to_number(x) }
-                                            translate_count(locale, "generic_views_count", views || 0, NumberFormatting::Short)
-                                        %></b>
-                                    </div>
-                                </h5>
                             </a>
+                            <h5 class="pure-g">
+                                <div class="pure-u-14-24">
+                                    <% if rv["ucid"]? %>
+                                        <b style="width:100%"><a href="/channel/<%= rv["ucid"] %>"><%= rv["author"]? %><% if rv["author_verified"]? == "true" %>&nbsp;<i class="icon ion ion-md-checkmark-circle"></i><% end %></a></b>
+                                    <% else %>
+                                        <b style="width:100%"><%= rv["author"]? %><% if rv["author_verified"]? == "true" %>&nbsp;<i class="icon ion ion-md-checkmark-circle"></i><% end %></b>
+                                    <% end %>
+                                </div>
+
+                                <div class="pure-u-10-24" style="text-align:right">
+                                    <b class="width:100%"><%=
+                                        views = rv["view_count"]?.try &.to_i?
+                                        views ||= rv["view_count_short"]?.try { |x| short_text_to_number(x) }
+                                        translate_count(locale, "generic_views_count", views || 0, NumberFormatting::Short)
+                                    %></b>
+                                </div>
+                            </h5>
                         <% end %>
                     <% end %>
                 </div>