PHP Rapid Automatic Keyword Extraction

PHP Rapid Automatic Keyword Extraction PHP Rapid Automatic Keyword Extraction PHP Rapid Automatic Keyword Extraction

use TextAnalysis\Analysis\Keywords\Rake;
use TextAnalysis\Documents\TokensDocument;
use TextAnalysis\Tokenizers\WhitespaceTokenizer;
use StopWordFactory;
use TextAnalysis\Filters;

class GetKeywords 
{

   const NGRAM_SIZE = 3;
    
    /**
     * @var \TextAnalysis\Interfaces\ITokenTransformation[]
     */
    protected $tokenFilters = [];
    
    /**
     * @var \TextAnalysis\Interfaces\ITokenTransformation[]
     */    
    protected $contentFilters = [];

    public function get($content)
    {            
        foreach($this->getContentFilters() as $contentFilter)
        {
            $content = $contentFilter->transform($content);
        }            
        return $this->getKeywordScores($content);
    }
    /**
     * 
     * @return \TextAnalysis\Interfaces\ITokenTransformation[]
     */
    public function getContentFilters()
    {
        if(empty($this->contentFilters)) {
            
            $lambdaFunc = function($word){
                return  preg_replace('/[\x00-\x1F\x80-\xFF]/u', ' ', $word);
            };
            
            $this->contentFilters = [
                new Filters\StripTagsFilter(),
                new Filters\LowerCaseFilter(),
                new Filters\NumbersFilter(),           
                new Filters\EmailFilter(),
                new Filters\UrlFilter(),
                new Filters\PossessiveNounFilter(),
                new Filters\QuotesFilter(),
                new Filters\PunctuationFilter(),
                new Filters\CharFilter(),
                new Filters\LambdaFilter($lambdaFunc),
                new Filters\WhitespaceFilter()     
            ];
        }
        return $this->contentFilters;
    }
    
    /**
     * 
     * @return \TextAnalysis\Interfaces\ITokenTransformation[]
     */
    public function getTokenFilters()
    {
        if(empty($this->tokenFilters)) {
            $stopwords = StopWordFactory::get('stop-words-fox.txt');
            $this->tokenFilters = [              
                new Filters\StopWordsFilter($stopwords),
            ];
        }        
        return $this->tokenFilters;
    }
    
    /**
     * 
     * @param string $content
     * @return array
     */
    public function getKeywordScores($content)
    {        
        $tokens = (new WhitespaceTokenizer())->tokenize($content);       
        $tokenDoc = new TokensDocument(array_map('strval', $tokens));
        unset($tokens);
                
        foreach($this->getTokenFilters() as $filter)
        {
            $tokenDoc->applyTransformation($filter, false);
        }        
          
        $size = count($tokenDoc->toArray());
        if($size < self::NGRAM_SIZE) {
            return [];
        }           
        
        $rake = new Rake($tokenDoc, self::NGRAM_SIZE);
        return $rake->getKeywordScores();
    }
}