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
9 Set.prototype.filter = function (f) {
10 return new Set([...this].filter(f));
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();
22 // find viable rows from json data
23 let ids = new Set(Object.keys(json));
24 const selection = {...json}; // clone
26 for (let cat of selection[''][3]) {
28 selection[cat][1] = 0; // keep root categories
31 if (this.preset.cat !== undefined) {
33 let children = this.preset.cat;
34 for (let loop = 0; children.length && loop < 20; loop++) {
35 for (let child of children) ids.add(child.toString());
36 children = children.map(cat => json[cat][3]).filter(is => is).flat()
39 if (this.preset.images) {
40 ids = ids.filter(id => json[id][2]);
42 if (this.preset.level !== undefined) {
43 ids = ids.filter(id => json[id][1] <= this.preset.level);
46 // keep only wanted ids
47 for (let id in selection) {
48 if (id && !ids.has(id)) {
53 // retain orphaned references in grandparent categories
54 for (let id in selection) {
55 selection[id][3] = function subresolve(subs) {
57 return (subs || []).flatMap(sub =>
58 sub in selection ? [sub] : json[sub] ? subresolve(json[sub][3]) : []
65 configure(params = window.location.hash.split('#')) {
66 const opts = new Map(params.map(arg => arg.split(/[:=](.*)/)));
67 for (let [query, val] of opts) {
68 if (query.match(/^\d+$/)) {
69 this.preset.cat = [parseInt(query)];
71 else if (query === 'level') {
72 this.preset.level = parseInt(val);
75 this.preset[query] = val;
78 this.preset.dataurl = `/data/wordlist.${this.preset.lang}.json`
82 this.form = document.getElementById('quiz');
87 fetch(this.preset.dataurl).then(res => res.json()).then(json => {
88 this.words = this.dataselect(json)
94 this.history.push([new Date().toISOString(), ...args]);
99 window.onbeforeunload = null;
100 fetch('/word/report', {method: 'POST', body: JSON.stringify(this.history)});
104 this.preset = {images: true, lang: 'en'};
107 window.onbeforeunload = e => {
110 window.onhashchange = e => {