+ this.data = this.datafilter(json);
+ let rows = Object.values(this.data);
+ rows = rows.filter(row => !row[3].length); // remove referenced categories
+ return rows.shuffle();
+ }
+
+ datafilter(json) {
+ // find viable rows from json data
+ let ids = new Set(Object.keys(json));
+ const selection = {...json}; // clone
+
+ for (let cat of selection[''][3]) {
+ if (selection[cat])
+ selection[cat][1] = 0; // keep root categories
+ }
+
+ if (this.preset.cat !== undefined) {
+ ids.clear();
+ let children = this.preset.cat;
+ for (let loop = 0; children.length && loop < 20; loop++) {
+ for (let child of children) ids.add(child.toString());
+ children = children.map(cat => json[cat][3]).filter(is => is).flat()
+ }
+ }
+ if (this.preset.images) {
+ ids = ids.filter(id => json[id][2]);
+ }
+ if (this.preset.level !== undefined) {
+ ids = ids.filter(id => json[id][1] <= this.preset.level);
+ }
+
+ // keep only wanted ids
+ for (let id in selection) {
+ if (id && !ids.has(id)) {
+ delete selection[id];
+ }
+ }
+
+ // retain orphaned references in grandparent categories
+ for (let id in selection) {
+ selection[id][3] = function subresolve(subs) {
+ //console.log(subs);
+ return (subs || []).flatMap(sub =>
+ sub in selection ? [sub] : json[sub] ? subresolve(json[sub][3]) : []
+ );
+ }(selection[id][3]);
+ }
+ return selection;
+ }
+
+ configure(params) {
+ const opts = new Map(params.map(arg => arg.split(/[:=](.*)/)));
+ for (let [query, val] of opts) {
+ if (query.match(/^\d+$/)) {
+ this.preset.cat = [parseInt(query)];
+ }
+ else if (query === 'level') {
+ this.preset.level = parseInt(val);
+ }
+ else {
+ this.preset[query] = val;
+ }
+ }