function generateKeywordsFromText($text) {
$stopWords = array(
'i', 'me', 'my', 'myself', 'we', 'our', 'ours', 'ourselves', 'you',
'your', 'yours', 'yourself', 'yourselves', 'he', 'him', 'his', 'himself', 'she',
'her', 'hers', 'herself', 'it', 'its', 'itself', 'they', 'them', 'their', 'theirs',
'themselves', 'what', 'which', 'who', 'whom', 'this', 'that', 'these', 'those', 'am',
'is', 'are', 'was', 'were', 'be', 'been', 'being', 'have', 'has', 'had', 'having',
'do', 'does', 'did', 'doing', 'a', 'an', 'the', 'and', 'but', 'if', 'or', 'because',
'as', 'until', 'while', 'of', 'at', 'by', 'for', 'with', 'about', 'against',
'between', 'into', 'through', 'during', 'before', 'after', 'above', 'below',
'to', 'from', 'up', 'down', 'in', 'out', 'on', 'off', 'over', 'under', 'again',
'further', 'then', 'once', 'here', 'there', 'when', 'where', 'why', 'how', 'all',
'any', 'both', 'each', 'few', 'more', 'most', 'other', 'some', 'such', 'no',
'nor', 'not', 'only', 'own', 'same', 'so', 'than', 'too', 'very', 's', 't',
'can', 'will', 'just', 'don', 'should', 'now', 'means', 'mean');
$text = trim($text);
$text = preg_replace('/\s\s+/i', '', $text); // replace multiple spaces
$text = strtolower($text);
preg_match_all('/\b.*?\b/i', $text, $wordsArr);
$wordsArr = $wordsArr[0];
foreach ($wordsArr as $key => $word) {
if ($word == '' || in_array($word, $stopWords) || strlen($word) <= 2 ) {
unset($wordsArr[$key]);
}
}
$wordOccurrences = array();
foreach ($wordsArr as $key => $word ) {
if (isset($wordOccurrences[$word]) ) {
$wordOccurrences[$word]++;
} else {
$wordOccurrences[$word] = 1;
}
}
$wordOccurrences = array_slice($wordOccurrences, 0, 12); // take only 12 keywords
$keywords = "";
foreach ($wordOccurrences as $key=>$value)
$keywords .= ", " . $key;
return trim($keywords, ",");
}
echo generateKeywordsFromText("PHP is a general-purpose scripting language especially suited " .
"to web development. It was originally created by Danish a " .
"Canadian programmer Rasmus Lerdorf in 1994. The PHP reference " .
"implementation is now produced by The PHP Group");
/*
run:
php, general, purpose, scripting, language, especially, suited, web,
development, originally, created, danish
*/
