Katten\Purge\Purger

Complexity

Total Complexity

12

Size/Duplication

Total Lines	110
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	3

Importance

Changes

0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	4	1
A	purge()	0	14	3
A	getPurgedCss()	0	13	3
A	filter()	0	15	3
A	preprocess()	0	11	2

<?php



namespace Katten\Purge;


use Sabberworm\CSS\CSSList\Document;
use Sabberworm\CSS\RuleSet\DeclarationBlock;



class Purger {


    /**
     * @var $cssBlocks
     *      A hash table of css DeclarationBlock objects
     */ 
    private $cssBlocks;
      
    

    public function __construct(BlockHashTable $hashTable) {
        
        $this->cssBlocks = $hashTable;
    }
    
    
        
    /**
     * Compares the CSS selectors against those found in the Crawler object
     * 
     * @param PurgeHtmlCrawler $dom
     */ 
    public function purge(PurgeHtmlCrawler $dom) {
        
        foreach ($this->cssBlocks->getBlockCollection() as $block) {
            
            $decBlock = $block[BlockHashTable::BLOCK_VALUE];
            
            $unusedBlock = $this->filter($decBlock, $dom);
            
            if ($unusedBlock == null) {
                $hash = $this->cssBlocks->hashBlock($decBlock);
                $this->cssBlocks->setUsedFlag($hash, true);
            }
        }
    }
    
    
    
    /**
     * Get all unused css from the cssBlocks hashtable
     * 
     * @return
     *      An array of DeclarationBlock objects
     */ 
    public function getPurgedCss() {
        
        $unusedCss = [];
        
        foreach ($this->cssBlocks->getBlockCollection() as $block) {
            
            if (!$block[BlockHashTable::IS_USED]) {
                $unusedCss[] = $block[BlockHashTable::BLOCK_VALUE];
            }
        }
        
        return $unusedCss;
    }
    
       
    
    /**
     * Filter out any used CSS on a selector by selector basis
     * 
     * @param DeclarationBlock $block
     * 
     * @return mixed
     *      Return the DeclarationBlock if no usage is found
     *      otherwise, return null
     */ 
    public function filter(DeclarationBlock $block, PurgeHtmlCrawler $dom) {
              
        foreach ($block->getSelectors() as $selector) {
            
            $processedSelector = $this->preprocess($selector->getSelector());
            
            $usage = $dom->findFirstInstance($processedSelector);

            if (count($usage) > 0) {
                return null;
            }
        }

        return $block;
    }
    
    
          
    /**
     * Strip any pseudo classes out of the selector 
     * 
     * @param string $selector
     * 
     * @return string
     *      A processed selector string
     */ 
    public function preprocess($selector) {

        if (strstr($selector, ':')) {
            $processedSelector = preg_replace('/\([^()]+\)|::?[^ ,:.(]+/i', '', $selector);
        }
        else {
            $processedSelector = $selector;
        }
               
        return $processedSelector;
    }
    
}