SimplePie::get_categories(): array|null

2371    public function get_categories()2372    {2373        $categories = [];2374 2375        foreach ((array) $this->get_channel_tags(self::NAMESPACE_ATOM_10, 'category') as $category) {2376            $term = null;2377            $scheme = null;2378            $label = null;2379            if (isset($category['attribs']['']['term'])) {2380                $term = $this->sanitize($category['attribs']['']['term'], self::CONSTRUCT_TEXT);2381            }2382            if (isset($category['attribs']['']['scheme'])) {2383                $scheme = $this->sanitize($category['attribs']['']['scheme'], self::CONSTRUCT_TEXT);2384            }2385            if (isset($category['attribs']['']['label'])) {2386                $label = $this->sanitize($category['attribs']['']['label'], self::CONSTRUCT_TEXT);2387            }2388            $categories[] = $this->registry->create(Category::class, [$term, $scheme, $label]);2389        }2390        foreach ((array) $this->get_channel_tags(self::NAMESPACE_RSS_20, 'category') as $category) {2391            // This is really the label, but keep this as the term also for BC.2392            // Label will also work on retrieving because that falls back to term.2393            $term = $this->sanitize($category['data'], self::CONSTRUCT_TEXT);2394            if (isset($category['attribs']['']['domain'])) {2395                $scheme = $this->sanitize($category['attribs']['']['domain'], self::CONSTRUCT_TEXT);2396            } else {2397                $scheme = null;2398            }2399            $categories[] = $this->registry->create(Category::class, [$term, $scheme, null]);2400        }2401        foreach ((array) $this->get_channel_tags(self::NAMESPACE_DC_11, 'subject') as $category) {2402            $categories[] = $this->registry->create(Category::class, [$this->sanitize($category['data'], self::CONSTRUCT_TEXT), null, null]);2403        }2404        foreach ((array) $this->get_channel_tags(self::NAMESPACE_DC_10, 'subject') as $category) {2405            $categories[] = $this->registry->create(Category::class, [$this->sanitize($category['data'], self::CONSTRUCT_TEXT), null, null]);2406        }2407 2408        if (!empty($categories)) {2409            return array_unique($categories);2410        }2411 2412        return null;2413    }