devdocs/assets/javascripts/lib/page.js

// TODO: This file was created by bulk-decaffeinate.
// Sanity-check the conversion and remove this comment.
/*
 * decaffeinate suggestions:
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS206: Consider reworking classes to avoid initClass
 * DS207: Consider shorter variations of null checks
 * DS208: Avoid top-level this
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/main/docs/suggestions.md
 */
/*
 * Based on github.com/visionmedia/page.js
 * Licensed under the MIT license
 * Copyright 2012 TJ Holowaychuk <tj@vision-media.ca>
*/

let running = false;
let currentState = null;
const callbacks = [];

this.page = function(value, fn) {
  if (typeof value === 'function') {
    page('*', value);
  } else if (typeof fn === 'function') {
    const route = new Route(value);
    callbacks.push(route.middleware(fn));
  } else if (typeof value === 'string') {
    page.show(value, fn);
  } else {
    page.start(value);
  }
};

page.start = function(options) {
  if (options == null) { options = {}; }
  if (!running) {
    running = true;
    addEventListener('popstate', onpopstate);
    addEventListener('click', onclick);
    page.replace(currentPath(), null, null, true);
  }
};

page.stop = function() {
  if (running) {
    running = false;
    removeEventListener('click', onclick);
    removeEventListener('popstate', onpopstate);
  }
};

page.show = function(path, state) {
  let res;
  if (path === (currentState != null ? currentState.path : undefined)) { return; }
  const context = new Context(path, state);
  const previousState = currentState;
  currentState = context.state;
  if (res = page.dispatch(context)) {
    currentState = previousState;
    location.assign(res);
  } else {
    context.pushState();
    updateCanonicalLink();
    track();
  }
  return context;
};

page.replace = function(path, state, skipDispatch, init) {
  let result;
  let context = new Context(path, state || currentState);
  context.init = init;
  currentState = context.state;
  if (!skipDispatch) { result = page.dispatch(context); }
  if (result) {
    context = new Context(result);
    context.init = init;
    currentState = context.state;
    page.dispatch(context);
  }
  context.replaceState();
  updateCanonicalLink();
  if (!skipDispatch) { track(); }
  return context;
};

page.dispatch = function(context) {
  let i = 0;
  var next = function() {
    let fn, res;
    if (fn = callbacks[i++]) { res = fn(context, next); }
    return res;
  };
  return next();
};

page.canGoBack = () => !Context.isIntialState(currentState);

page.canGoForward = () => !Context.isLastState(currentState);

var currentPath = () => location.pathname + location.search + location.hash;

class Context {
  static initClass() {
    this.initialPath = currentPath();
    this.sessionId = Date.now();
    this.stateId = 0;
  }

  static isIntialState(state) {
    return state.id === 0;
  }

  static isLastState(state) {
    return state.id === (this.stateId - 1);
  }

  static isInitialPopState(state) {
    return (state.path === this.initialPath) && (this.stateId === 1);
  }

  static isSameSession(state) {
    return state.sessionId === this.sessionId;
  }

  constructor(path, state) {
    if (path == null) { path = '/'; }
    this.path = path;
    if (state == null) { state = {}; }
    this.state = state;
    this.pathname = this.path.replace(/(?:\?([^#]*))?(?:#(.*))?$/, (_, query, hash) => {
      this.query = query;
      this.hash = hash;
      return '';
    });

    if (this.state.id == null) { this.state.id = this.constructor.stateId++; }
    if (this.state.sessionId == null) { this.state.sessionId = this.constructor.sessionId; }
    this.state.path = this.path;
  }

  pushState() {
    history.pushState(this.state, '', this.path);
  }

  replaceState() {
    try { history.replaceState(this.state, '', this.path); } catch (error) {} // NS_ERROR_FAILURE in Firefox
  }
}
Context.initClass();

class Route {
  constructor(path, options) {
    this.path = path;
    if (options == null) { options = {}; }
    this.keys = [];
    this.regexp = pathtoRegexp(this.path, this.keys);
  }

  middleware(fn) {
    return (context, next) => {
      let params;
      if (this.match(context.pathname, (params = []))) {
        context.params = params;
        return fn(context, next);
      } else {
        return next();
      }
    };
  }

  match(path, params) {
    let matchData;
    if (!(matchData = this.regexp.exec(path))) { return; }

    const iterable = matchData.slice(1);
    for (let i = 0; i < iterable.length; i++) {
      var key;
      var value = iterable[i];
      if (typeof value === 'string') { value = decodeURIComponent(value); }
      if ((key = this.keys[i])) {
        params[key.name] = value;
      } else {
        params.push(value);
      }
    }
    return true;
  }
}

var pathtoRegexp = function(path, keys) {
  if (path instanceof RegExp) { return path; }

  if (path instanceof Array) { path = `(${path.join('|')})`; }
  path = path
    .replace(/\/\(/g, '(?:/')
    .replace(/(\/)?(\.)?:(\w+)(?:(\(.*?\)))?(\?)?/g, function(_, slash, format, key, capture, optional) {
      if (slash == null) { slash = ''; }
      if (format == null) { format = ''; }
      keys.push({name: key, optional: !!optional});
      let str = optional ? '' : slash;
      str += '(?:';
      if (optional) { str += slash; }
      str += format;
      str += capture || (format ? '([^/.]+?)' : '([^/]+?)');
      str += ')';
      if (optional) { str += optional; }
      return str;
  }).replace(/([\/.])/g, '\\$1')
    .replace(/\*/g, '(.*)');

  return new RegExp(`^${path}$`);
};

var onpopstate = function(event) {
  if (!event.state || Context.isInitialPopState(event.state)) { return; }

  if (Context.isSameSession(event.state)) {
    page.replace(event.state.path, event.state);
  } else {
    location.reload();
  }
};

var onclick = function(event) {
  try {
    if ((event.which !== 1) || event.metaKey || event.ctrlKey || event.shiftKey || event.defaultPrevented) { return; }
  } catch (error) {
    return;
  }

  let link = $.eventTarget(event);
  while (link && (link.tagName !== 'A')) { link = link.parentNode; }

  if (link && !link.target && isSameOrigin(link.href)) {
    event.preventDefault();
    let path = link.pathname + link.search + link.hash;
    path = path.replace(/^\/\/+/, '/'); // IE11 bug
    page.show(path);
  }
};

var isSameOrigin = url => url.indexOf(`${location.protocol}//${location.hostname}`) === 0;

var updateCanonicalLink = function() {
  if (!this.canonicalLink) { this.canonicalLink = document.head.querySelector('link[rel="canonical"]'); }
  return this.canonicalLink.setAttribute('href', `https://${location.host}${location.pathname}`);
};

const trackers = [];

page.track = function(fn) {
  trackers.push(fn);
};

var track = function() {
  if (app.config.env !== 'production') { return; }
  if (navigator.doNotTrack === '1') { return; }
  if (navigator.globalPrivacyControl) { return; }

  const consentGiven = Cookies.get('analyticsConsent');
  const consentAsked = Cookies.get('analyticsConsentAsked');

  if (consentGiven === '1') {
    for (var tracker of Array.from(trackers)) { tracker.call(); }
  } else if ((consentGiven === undefined) && (consentAsked === undefined)) {
    // Only ask for consent once per browser session
    Cookies.set('analyticsConsentAsked', '1');

    new app.views.Notif('AnalyticsConsent', {autoHide: null});
  }
};

this.resetAnalytics = function() {
  for (var cookie of Array.from(document.cookie.split(/;\s?/))) {
    var name = cookie.split('=')[0];
    if ((name[0] === '_') && (name[1] !== '_')) {
      Cookies.expire(name);
    }
  }
};