word/quiz.js

   1 Array.prototype.shuffle = function () {
   2         for (let i = this.length - 1; i > 0; i--) {
   3                 const j = Math.floor(Math.random() * (i + 1)); // random index 0..i
   4                 [this[i], this[j]] = [this[j], this[i]]; // swap elements
   5         }
   6         return this;
   7 };
   8
   9 Set.prototype.filter = function (f) {
  10         return new Set([...this].filter(f));
  11 };
  12
  13 class WordQuiz {
  14         dataselect(json) {
  15                 this.data = this.datafilter(json);
  16                 let rows = Object.values(this.data);
  17                 rows = rows.filter(row => !row[3].length); // remove referenced categories
  18                 return rows.shuffle();
  19         }
  20
  21         datafilter(json) {
  22                 // find viable rows from json data
  23                 let ids = new Set(Object.keys(json));
  24                 const selection = {...json}; // clone
  25
  26                 if (this.preset.cat !== undefined) {
  27                         ids.clear();
  28                         let children = [this.preset.cat];
  29                         for (let loop = 0; children.length && loop < 20; loop++) {
  30                                 for (let child of children) ids.add(child.toString());
  31                                 children = children.map(cat => json[cat][3]).filter(is => is).flat()
  32                         }
  33                 }
  34                 if (this.preset.image) {
  35                         ids = ids.filter(id => json[id][2]);
  36                 }
  37                 if (this.preset.level !== undefined) {
  38                         ids = ids.filter(id => json[id][1] <= this.preset.level);
  39                 }
  40
  41                 // keep only wanted ids
  42                 for (let id in selection) {
  43                         if (id && !ids.has(id)) {
  44                                 delete selection[id];
  45                         }
  46                 }
  47
  48                 // retain orphaned references in grandparent categories
  49                 for (let id in selection) {
  50                         selection[id][3] = function subresolve(subs) {
  51                                 //console.log(subs);
  52                                 return (subs || []).flatMap(sub =>
  53                                         sub in selection ? [sub] : subresolve(json[sub][3])
  54                                 );
  55                         }(selection[id][3]);
  56                 }
  57                 return selection;
  58         }
  59
  60         load(dataurl) {
  61                 this.preset = {};
  62                 let input;
  63                 if (input = window.location.hash.match(/\d+/)) {
  64                         this.preset.cat = parseInt(input[0]);
  65                 }
  66                 if (window.location.hash.match(/a/)) {
  67                         this.preset.level = 3;
  68                 }
  69
  70                 fetch(dataurl).then(res => res.json()).then(json => {
  71                         this.words = this.dataselect(json)
  72                         this.setup();
  73                 });
  74         }
  75
  76         log(...args) {
  77                 this.history.push([new Date().toISOString(), ...args]);
  78         }
  79
  80         stop(...args) {
  81                 this.log(...args);
  82                 window.onbeforeunload = null;
  83                 fetch('/word/report', {method: 'POST', body: JSON.stringify(this.history)});
  84         }
  85
  86         constructor(dataurl) {
  87                 this.load(dataurl);
  88                 this.history = [];
  89                 window.onbeforeunload = e => {
  90                         this.stop('abort');
  91                 };
  92         }
  93 }