public function getAllKeywordsSorted($text)
{
// split the text into words
$words = $this->config->trigger('get_words', $text);
// get the candidates
$keywords = $this->config->trigger('filter_keywords', $words);
// normalize each candidate
$normalized = $this->config->trigger('normalize_keywords', $keywords);
if (count($keywords) != count($normalized)) {
throw new \RuntimeException("{normalize_keywords} event returned invalid data");
}
$graph = new PageRank();
$sorted = $graph->sort(array_values($normalized), true);
if ($sorted == $normalized) {
// PageRank failed, probably because the input was invalid
return [];
}
$top = array_slice($sorted, 0, 10);
// build an index of words and positions (so we can collapse compount keywords)
$index = [];
$pindex = [];
// search for coumpounds keywords
$prev = [];
$phrases = [];
foreach ($normalized as $pos => $word) {
if (empty($top[$word])) {
if (count($prev) > 1 && count($prev) < 4) {
$phrases[] = $prev;
}
$prev = [];
continue;
}
$prev[] = [$pos, $word];
}
if (count($prev) > 1 && count($prev) < 4) {
$phrases[] = $prev;
}
foreach ($phrases as $prev) {
$start = current($prev)[0];
$end = end($prev)[0];
$zwords = array_slice($words, $start, $end - $start + 1, true);
if (count(array_filter($zwords, 'ctype_punct')) > 0) {
continue;
}
$phrase = implode(' ', $zwords);
$score = 0;
foreach ($prev as $word) {
$score += $top[$word[1]];
}
$sorted[trim($phrase)] = $score / ($end - $start);
}
// denormalize each single words
foreach ($normalized as $pos => $word) {
if (!empty($sorted[$word]) && $word != $words[$pos]) {
$sorted[$words[$pos]] = $sorted[$word];
unset($sorted[$word]);
}
}
arsort($sorted);
return $sorted;
}
